[ Index ]

PHP Cross Reference of WordPress Trunk (Updated Daily)

Search

title

Body

[close]

/wp-includes/ -> link-template.php (source)

   1  <?php
   2  /**
   3   * WordPress Link Template Functions
   4   *
   5   * @package WordPress
   6   * @subpackage Template
   7   */
   8  
   9  /**
  10   * Displays the permalink for the current post.
  11   *
  12   * @since 1.2.0
  13   * @since 4.4.0 Added the `$post` parameter.
  14   *
  15   * @param int|WP_Post $post Optional. Post ID or post object. Default is the global `$post`.
  16   */
  17  function the_permalink( $post = 0 ) {
  18      /**
  19       * Filters the display of the permalink for the current post.
  20       *
  21       * @since 1.5.0
  22       * @since 4.4.0 Added the `$post` parameter.
  23       *
  24       * @param string      $permalink The permalink for the current post.
  25       * @param int|WP_Post $post      Post ID, WP_Post object, or 0. Default 0.
  26       */
  27      echo esc_url( apply_filters( 'the_permalink', get_permalink( $post ), $post ) );
  28  }
  29  
  30  /**
  31   * Retrieves a trailing-slashed string if the site is set for adding trailing slashes.
  32   *
  33   * Conditionally adds a trailing slash if the permalink structure has a trailing
  34   * slash, strips the trailing slash if not. The string is passed through the
  35   * {@see 'user_trailingslashit'} filter. Will remove trailing slash from string, if
  36   * site is not set to have them.
  37   *
  38   * @since 2.2.0
  39   *
  40   * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
  41   *
  42   * @param string $url         URL with or without a trailing slash.
  43   * @param string $type_of_url Optional. The type of URL being considered (e.g. single, category, etc)
  44   *                            for use in the filter. Default empty string.
  45   * @return string The URL with the trailing slash appended or stripped.
  46   */
  47  function user_trailingslashit( $url, $type_of_url = '' ) {
  48      global $wp_rewrite;
  49      if ( $wp_rewrite->use_trailing_slashes ) {
  50          $url = trailingslashit( $url );
  51      } else {
  52          $url = untrailingslashit( $url );
  53      }
  54  
  55      /**
  56       * Filters the trailing-slashed string, depending on whether the site is set to use trailing slashes.
  57       *
  58       * @since 2.2.0
  59       *
  60       * @param string $url         URL with or without a trailing slash.
  61       * @param string $type_of_url The type of URL being considered. Accepts 'single', 'single_trackback',
  62       *                            'single_feed', 'single_paged', 'commentpaged', 'paged', 'home', 'feed',
  63       *                            'category', 'page', 'year', 'month', 'day', 'post_type_archive'.
  64       */
  65      return apply_filters( 'user_trailingslashit', $url, $type_of_url );
  66  }
  67  
  68  /**
  69   * Displays the permalink anchor for the current post.
  70   *
  71   * The permalink mode title will use the post title for the 'a' element 'id'
  72   * attribute. The id mode uses 'post-' with the post ID for the 'id' attribute.
  73   *
  74   * @since 0.71
  75   *
  76   * @param string $mode Optional. Permalink mode. Accepts 'title' or 'id'. Default 'id'.
  77   */
  78  function permalink_anchor( $mode = 'id' ) {
  79      $post = get_post();
  80      switch ( strtolower( $mode ) ) {
  81          case 'title':
  82              $title = sanitize_title( $post->post_title ) . '-' . $post->ID;
  83              echo '<a id="' . $title . '"></a>';
  84              break;
  85          case 'id':
  86          default:
  87              echo '<a id="post-' . $post->ID . '"></a>';
  88              break;
  89      }
  90  }
  91  
  92  /**
  93   * Determine whether post should always use a plain permalink structure.
  94   *
  95   * @since 5.7.0
  96   *
  97   * @param int|WP_Post|null $post   Optional. Post ID or post object. Defaults to global $post.
  98   * @param bool|null        $sample Optional. Whether to force consideration based on sample links.
  99   *                                 If omitted, a sample link is generated if a post object is passed
 100   *                                 with the filter property set to 'sample'.
 101   * @return bool Whether to use a plain permalink structure.
 102   */
 103  function wp_force_plain_post_permalink( $post = null, $sample = null ) {
 104      if (
 105          null === $sample &&
 106          is_object( $post ) &&
 107          isset( $post->filter ) &&
 108          'sample' === $post->filter
 109      ) {
 110          $sample = true;
 111      } else {
 112          $post   = get_post( $post );
 113          $sample = $sample ?? false;
 114      }
 115  
 116      if ( ! $post ) {
 117          return true;
 118      }
 119  
 120      $post_status_obj = get_post_status_object( get_post_status( $post ) );
 121      $post_type_obj   = get_post_type_object( get_post_type( $post ) );
 122  
 123      if ( ! $post_status_obj || ! $post_type_obj ) {
 124          return true;
 125      }
 126  
 127      if (
 128          // Publicly viewable links never have plain permalinks.
 129          is_post_status_viewable( $post_status_obj ) ||
 130          (
 131              // Private posts don't have plain permalinks if the user can read them.
 132              $post_status_obj->private &&
 133              current_user_can( 'read_post', $post->ID )
 134          ) ||
 135          // Protected posts don't have plain links if getting a sample URL.
 136          ( $post_status_obj->protected && $sample )
 137      ) {
 138          return false;
 139      }
 140  
 141      return true;
 142  }
 143  
 144  /**
 145   * Retrieves the full permalink for the current post or post ID.
 146   *
 147   * This function is an alias for get_permalink().
 148   *
 149   * @since 3.9.0
 150   *
 151   * @see get_permalink()
 152   *
 153   * @param int|WP_Post $post      Optional. Post ID or post object. Default is the global `$post`.
 154   * @param bool        $leavename Optional. Whether to keep post name or page name. Default false.
 155   * @return string|false The permalink URL. False if the post does not exist.
 156   */
 157  function get_the_permalink( $post = 0, $leavename = false ) {
 158      return get_permalink( $post, $leavename );
 159  }
 160  
 161  /**
 162   * Retrieves the full permalink for the current post or post ID.
 163   *
 164   * @since 1.0.0
 165   *
 166   * @param int|WP_Post $post      Optional. Post ID or post object. Default is the global `$post`.
 167   * @param bool        $leavename Optional. Whether to keep post name or page name. Default false.
 168   * @return string|false The permalink URL. False if the post does not exist.
 169   */
 170  function get_permalink( $post = 0, $leavename = false ) {
 171      $rewritecode = array(
 172          '%year%',
 173          '%monthnum%',
 174          '%day%',
 175          '%hour%',
 176          '%minute%',
 177          '%second%',
 178          $leavename ? '' : '%postname%',
 179          '%post_id%',
 180          '%category%',
 181          '%author%',
 182          $leavename ? '' : '%pagename%',
 183      );
 184  
 185      if ( is_object( $post ) && isset( $post->filter ) && 'sample' === $post->filter ) {
 186          $sample = true;
 187      } else {
 188          $post   = get_post( $post );
 189          $sample = false;
 190      }
 191  
 192      if ( empty( $post->ID ) ) {
 193          return false;
 194      }
 195  
 196      if ( 'page' === $post->post_type ) {
 197          return get_page_link( $post, $leavename, $sample );
 198      } elseif ( 'attachment' === $post->post_type ) {
 199          return get_attachment_link( $post, $leavename );
 200      } elseif ( in_array( $post->post_type, get_post_types( array( '_builtin' => false ) ), true ) ) {
 201          return get_post_permalink( $post, $leavename, $sample );
 202      }
 203  
 204      $permalink = get_option( 'permalink_structure' );
 205  
 206      /**
 207       * Filters the permalink structure for a post before token replacement occurs.
 208       *
 209       * Only applies to posts with post_type of 'post'.
 210       *
 211       * @since 3.0.0
 212       *
 213       * @param string  $permalink The site's permalink structure.
 214       * @param WP_Post $post      The post in question.
 215       * @param bool    $leavename Whether to keep the post name.
 216       */
 217      $permalink = apply_filters( 'pre_post_link', $permalink, $post, $leavename );
 218  
 219      if (
 220          $permalink &&
 221          ! wp_force_plain_post_permalink( $post )
 222      ) {
 223  
 224          $category = '';
 225          if ( str_contains( $permalink, '%category%' ) ) {
 226              $cats = get_the_category( $post->ID );
 227              if ( $cats ) {
 228                  $cats = wp_list_sort(
 229                      $cats,
 230                      array(
 231                          'term_id' => 'ASC',
 232                      )
 233                  );
 234  
 235                  /**
 236                   * Filters the category that gets used in the %category% permalink token.
 237                   *
 238                   * @since 3.5.0
 239                   *
 240                   * @param WP_Term  $cat  The category to use in the permalink.
 241                   * @param array    $cats Array of all categories (WP_Term objects) associated with the post.
 242                   * @param WP_Post  $post The post in question.
 243                   */
 244                  $category_object = apply_filters( 'post_link_category', $cats[0], $cats, $post );
 245  
 246                  $category_object = get_term( $category_object, 'category' );
 247                  $category        = $category_object->slug;
 248                  if ( $category_object->parent ) {
 249                      $category = get_category_parents( $category_object->parent, false, '/', true ) . $category;
 250                  }
 251              }
 252              /*
 253               * Show default category in permalinks,
 254               * without having to assign it explicitly.
 255               */
 256              if ( empty( $category ) ) {
 257                  $default_category = get_term( get_option( 'default_category' ), 'category' );
 258                  if ( $default_category && ! is_wp_error( $default_category ) ) {
 259                      $category = $default_category->slug;
 260                  }
 261              }
 262          }
 263  
 264          $author = '';
 265          if ( str_contains( $permalink, '%author%' ) ) {
 266              $authordata = get_userdata( $post->post_author );
 267              $author     = $authordata->user_nicename;
 268          }
 269  
 270          /*
 271           * This is not an API call because the permalink is based on the stored post_date value,
 272           * which should be parsed as local time regardless of the default PHP timezone.
 273           */
 274          $date = explode( ' ', str_replace( array( '-', ':' ), ' ', $post->post_date ) );
 275  
 276          $rewritereplace = array(
 277              $date[0],
 278              $date[1],
 279              $date[2],
 280              $date[3],
 281              $date[4],
 282              $date[5],
 283              $post->post_name,
 284              $post->ID,
 285              $category,
 286              $author,
 287              $post->post_name,
 288          );
 289  
 290          $permalink = home_url( str_replace( $rewritecode, $rewritereplace, $permalink ) );
 291          $permalink = user_trailingslashit( $permalink, 'single' );
 292  
 293      } else { // If they're not using the fancy permalink option.
 294          $permalink = home_url( '?p=' . $post->ID );
 295      }
 296  
 297      /**
 298       * Filters the permalink for a post.
 299       *
 300       * Only applies to posts with post_type of 'post'.
 301       *
 302       * @since 1.5.0
 303       *
 304       * @param string  $permalink The post's permalink.
 305       * @param WP_Post $post      The post in question.
 306       * @param bool    $leavename Whether to keep the post name.
 307       */
 308      return apply_filters( 'post_link', $permalink, $post, $leavename );
 309  }
 310  
 311  /**
 312   * Retrieves the permalink for a post of a custom post type.
 313   *
 314   * @since 3.0.0
 315   * @since 6.1.0 Returns false if the post does not exist.
 316   *
 317   * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
 318   *
 319   * @param int|WP_Post $post      Optional. Post ID or post object. Default is the global `$post`.
 320   * @param bool        $leavename Optional. Whether to keep post name. Default false.
 321   * @param bool        $sample    Optional. Is it a sample permalink. Default false.
 322   * @return string|false The post permalink URL. False if the post does not exist.
 323   */
 324  function get_post_permalink( $post = 0, $leavename = false, $sample = false ) {
 325      global $wp_rewrite;
 326  
 327      $post = get_post( $post );
 328  
 329      if ( ! $post ) {
 330          return false;
 331      }
 332  
 333      $post_link = $wp_rewrite->get_extra_permastruct( $post->post_type );
 334  
 335      $slug = $post->post_name;
 336  
 337      $force_plain_link = wp_force_plain_post_permalink( $post );
 338  
 339      $post_type = get_post_type_object( $post->post_type );
 340  
 341      if ( $post_type->hierarchical ) {
 342          $slug = get_page_uri( $post );
 343      }
 344  
 345      if ( ! empty( $post_link ) && ( ! $force_plain_link || $sample ) ) {
 346          if ( ! $leavename ) {
 347              $post_link = str_replace( "%$post->post_type%", $slug, $post_link );
 348          }
 349          $post_link = home_url( user_trailingslashit( $post_link ) );
 350      } else {
 351          if ( $post_type->query_var && ( isset( $post->post_status ) && ! $force_plain_link ) ) {
 352              $post_link = add_query_arg( $post_type->query_var, $slug, '' );
 353          } else {
 354              $post_link = add_query_arg(
 355                  array(
 356                      'post_type' => $post->post_type,
 357                      'p'         => $post->ID,
 358                  ),
 359                  ''
 360              );
 361          }
 362          $post_link = home_url( $post_link );
 363      }
 364  
 365      /**
 366       * Filters the permalink for a post of a custom post type.
 367       *
 368       * @since 3.0.0
 369       *
 370       * @param string  $post_link The post's permalink.
 371       * @param WP_Post $post      The post in question.
 372       * @param bool    $leavename Whether to keep the post name.
 373       * @param bool    $sample    Is it a sample permalink.
 374       */
 375      return apply_filters( 'post_type_link', $post_link, $post, $leavename, $sample );
 376  }
 377  
 378  /**
 379   * Retrieves the permalink for the current page or page ID.
 380   *
 381   * Respects page_on_front. Use this one.
 382   *
 383   * @since 1.5.0
 384   *
 385   * @param int|WP_Post $post      Optional. Post ID or object. Default uses the global `$post`.
 386   * @param bool        $leavename Optional. Whether to keep the page name. Default false.
 387   * @param bool        $sample    Optional. Whether it should be treated as a sample permalink.
 388   *                               Default false.
 389   * @return string The page permalink.
 390   */
 391  function get_page_link( $post = 0, $leavename = false, $sample = false ) {
 392      $post = get_post( $post );
 393  
 394      if ( 'page' === get_option( 'show_on_front' ) && (int) get_option( 'page_on_front' ) === $post->ID ) {
 395          $link = home_url( '/' );
 396      } else {
 397          $link = _get_page_link( $post, $leavename, $sample );
 398      }
 399  
 400      /**
 401       * Filters the permalink for a page.
 402       *
 403       * @since 1.5.0
 404       *
 405       * @param string $link    The page's permalink.
 406       * @param int    $post_id The ID of the page.
 407       * @param bool   $sample  Is it a sample permalink.
 408       */
 409      return apply_filters( 'page_link', $link, $post->ID, $sample );
 410  }
 411  
 412  /**
 413   * Retrieves the page permalink.
 414   *
 415   * Ignores page_on_front. Internal use only.
 416   *
 417   * @since 2.1.0
 418   * @access private
 419   *
 420   * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
 421   *
 422   * @param int|WP_Post $post      Optional. Post ID or object. Default uses the global `$post`.
 423   * @param bool        $leavename Optional. Whether to keep the page name. Default false.
 424   * @param bool        $sample    Optional. Whether it should be treated as a sample permalink.
 425   *                               Default false.
 426   * @return string The page permalink.
 427   */
 428  function _get_page_link( $post = 0, $leavename = false, $sample = false ) {
 429      global $wp_rewrite;
 430  
 431      $post = get_post( $post );
 432  
 433      $force_plain_link = wp_force_plain_post_permalink( $post );
 434  
 435      $link = $wp_rewrite->get_page_permastruct();
 436  
 437      if ( ! empty( $link ) && ( ( isset( $post->post_status ) && ! $force_plain_link ) || $sample ) ) {
 438          if ( ! $leavename ) {
 439              $link = str_replace( '%pagename%', get_page_uri( $post ), $link );
 440          }
 441  
 442          $link = home_url( $link );
 443          $link = user_trailingslashit( $link, 'page' );
 444      } else {
 445          $link = home_url( '?page_id=' . $post->ID );
 446      }
 447  
 448      /**
 449       * Filters the permalink for a non-page_on_front page.
 450       *
 451       * @since 2.1.0
 452       *
 453       * @param string $link    The page's permalink.
 454       * @param int    $post_id The ID of the page.
 455       */
 456      return apply_filters( '_get_page_link', $link, $post->ID );
 457  }
 458  
 459  /**
 460   * Retrieves the permalink for an attachment.
 461   *
 462   * This can be used in the WordPress Loop or outside of it.
 463   *
 464   * @since 2.0.0
 465   *
 466   * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
 467   *
 468   * @param int|WP_Post $post      Optional. Post ID or object. Default uses the global `$post`.
 469   * @param bool        $leavename Optional. Whether to keep the page name. Default false.
 470   * @return string The attachment permalink.
 471   */
 472  function get_attachment_link( $post = null, $leavename = false ) {
 473      global $wp_rewrite;
 474  
 475      $link = false;
 476  
 477      $post             = get_post( $post );
 478      $force_plain_link = wp_force_plain_post_permalink( $post );
 479      $parent_id        = $post->post_parent;
 480      $parent           = $parent_id ? get_post( $parent_id ) : false;
 481      $parent_valid     = true; // Default for no parent.
 482      if (
 483          $parent_id &&
 484          (
 485              $post->post_parent === $post->ID ||
 486              ! $parent ||
 487              ! is_post_type_viewable( get_post_type( $parent ) )
 488          )
 489      ) {
 490          // Post is either its own parent or parent post unavailable.
 491          $parent_valid = false;
 492      }
 493  
 494      if ( $force_plain_link || ! $parent_valid ) {
 495          $link = false;
 496      } elseif ( $wp_rewrite->using_permalinks() && $parent ) {
 497          if ( 'page' === $parent->post_type ) {
 498              $parentlink = _get_page_link( $post->post_parent ); // Ignores page_on_front.
 499          } else {
 500              $parentlink = get_permalink( $post->post_parent );
 501          }
 502  
 503          if ( is_numeric( $post->post_name ) || str_contains( get_option( 'permalink_structure' ), '%category%' ) ) {
 504              $name = 'attachment/' . $post->post_name; // <permalink>/<int>/ is paged so we use the explicit attachment marker.
 505          } else {
 506              $name = $post->post_name;
 507          }
 508  
 509          if ( ! str_contains( $parentlink, '?' ) ) {
 510              $link = user_trailingslashit( trailingslashit( $parentlink ) . '%postname%' );
 511          }
 512  
 513          if ( ! $leavename ) {
 514              $link = str_replace( '%postname%', $name, $link );
 515          }
 516      } elseif ( $wp_rewrite->using_permalinks() && ! $leavename ) {
 517          $link = home_url( user_trailingslashit( $post->post_name ) );
 518      }
 519  
 520      if ( ! $link ) {
 521          $link = home_url( '/?attachment_id=' . $post->ID );
 522      }
 523  
 524      /**
 525       * Filters the permalink for an attachment.
 526       *
 527       * @since 2.0.0
 528       * @since 5.6.0 Providing an empty string will now disable
 529       *              the view attachment page link on the media modal.
 530       *
 531       * @param string $link    The attachment's permalink.
 532       * @param int    $post_id Attachment ID.
 533       */
 534      return apply_filters( 'attachment_link', $link, $post->ID );
 535  }
 536  
 537  /**
 538   * Retrieves the permalink for the year archives.
 539   *
 540   * @since 1.5.0
 541   *
 542   * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
 543   *
 544   * @param int|false $year Integer of year. False for current year.
 545   * @return string The permalink for the specified year archive.
 546   */
 547  function get_year_link( $year ) {
 548      global $wp_rewrite;
 549      if ( ! $year ) {
 550          $year = current_time( 'Y' );
 551      }
 552      $yearlink = $wp_rewrite->get_year_permastruct();
 553      if ( ! empty( $yearlink ) ) {
 554          $yearlink = str_replace( '%year%', $year, $yearlink );
 555          $yearlink = home_url( user_trailingslashit( $yearlink, 'year' ) );
 556      } else {
 557          $yearlink = home_url( '?m=' . $year );
 558      }
 559  
 560      /**
 561       * Filters the year archive permalink.
 562       *
 563       * @since 1.5.0
 564       *
 565       * @param string $yearlink Permalink for the year archive.
 566       * @param int    $year     Year for the archive.
 567       */
 568      return apply_filters( 'year_link', $yearlink, $year );
 569  }
 570  
 571  /**
 572   * Retrieves the permalink for the month archives with year.
 573   *
 574   * @since 1.0.0
 575   *
 576   * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
 577   *
 578   * @param int|false $year  Integer of year. False for current year.
 579   * @param int|false $month Integer of month. False for current month.
 580   * @return string The permalink for the specified month and year archive.
 581   */
 582  function get_month_link( $year, $month ) {
 583      global $wp_rewrite;
 584      if ( ! $year ) {
 585          $year = current_time( 'Y' );
 586      }
 587      if ( ! $month ) {
 588          $month = current_time( 'm' );
 589      }
 590      $monthlink = $wp_rewrite->get_month_permastruct();
 591      if ( ! empty( $monthlink ) ) {
 592          $monthlink = str_replace( '%year%', $year, $monthlink );
 593          $monthlink = str_replace( '%monthnum%', zeroise( (int) $month, 2 ), $monthlink );
 594          $monthlink = home_url( user_trailingslashit( $monthlink, 'month' ) );
 595      } else {
 596          $monthlink = home_url( '?m=' . $year . zeroise( $month, 2 ) );
 597      }
 598  
 599      /**
 600       * Filters the month archive permalink.
 601       *
 602       * @since 1.5.0
 603       *
 604       * @param string $monthlink Permalink for the month archive.
 605       * @param int    $year      Year for the archive.
 606       * @param int    $month     The month for the archive.
 607       */
 608      return apply_filters( 'month_link', $monthlink, $year, $month );
 609  }
 610  
 611  /**
 612   * Retrieves the permalink for the day archives with year and month.
 613   *
 614   * @since 1.0.0
 615   *
 616   * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
 617   *
 618   * @param int|false $year  Integer of year. False for current year.
 619   * @param int|false $month Integer of month. False for current month.
 620   * @param int|false $day   Integer of day. False for current day.
 621   * @return string The permalink for the specified day, month, and year archive.
 622   */
 623  function get_day_link( $year, $month, $day ) {
 624      global $wp_rewrite;
 625      if ( ! $year ) {
 626          $year = current_time( 'Y' );
 627      }
 628      if ( ! $month ) {
 629          $month = current_time( 'm' );
 630      }
 631      if ( ! $day ) {
 632          $day = current_time( 'j' );
 633      }
 634  
 635      $daylink = $wp_rewrite->get_day_permastruct();
 636      if ( ! empty( $daylink ) ) {
 637          $daylink = str_replace( '%year%', $year, $daylink );
 638          $daylink = str_replace( '%monthnum%', zeroise( (int) $month, 2 ), $daylink );
 639          $daylink = str_replace( '%day%', zeroise( (int) $day, 2 ), $daylink );
 640          $daylink = home_url( user_trailingslashit( $daylink, 'day' ) );
 641      } else {
 642          $daylink = home_url( '?m=' . $year . zeroise( $month, 2 ) . zeroise( $day, 2 ) );
 643      }
 644  
 645      /**
 646       * Filters the day archive permalink.
 647       *
 648       * @since 1.5.0
 649       *
 650       * @param string $daylink Permalink for the day archive.
 651       * @param int    $year    Year for the archive.
 652       * @param int    $month   Month for the archive.
 653       * @param int    $day     The day for the archive.
 654       */
 655      return apply_filters( 'day_link', $daylink, $year, $month, $day );
 656  }
 657  
 658  /**
 659   * Displays the permalink for the feed type.
 660   *
 661   * @since 3.0.0
 662   *
 663   * @param string $anchor The link's anchor text.
 664   * @param string $feed   Optional. Feed type. Possible values include 'rss2', 'atom'.
 665   *                       Default is the value of get_default_feed().
 666   */
 667  function the_feed_link( $anchor, $feed = '' ) {
 668      $link = '<a href="' . esc_url( get_feed_link( $feed ) ) . '">' . $anchor . '</a>';
 669  
 670      /**
 671       * Filters the feed link anchor tag.
 672       *
 673       * @since 3.0.0
 674       *
 675       * @param string $link The complete anchor tag for a feed link.
 676       * @param string $feed The feed type. Possible values include 'rss2', 'atom',
 677       *                     or an empty string for the default feed type.
 678       */
 679      echo apply_filters( 'the_feed_link', $link, $feed );
 680  }
 681  
 682  /**
 683   * Retrieves the permalink for the feed type.
 684   *
 685   * @since 1.5.0
 686   *
 687   * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
 688   *
 689   * @param string $feed Optional. Feed type. Possible values include 'rss2', 'atom'.
 690   *                     Default is the value of get_default_feed().
 691   * @return string The feed permalink.
 692   */
 693  function get_feed_link( $feed = '' ) {
 694      global $wp_rewrite;
 695  
 696      $permalink = $wp_rewrite->get_feed_permastruct();
 697  
 698      if ( $permalink ) {
 699          if ( str_contains( $feed, 'comments_' ) ) {
 700              $feed      = str_replace( 'comments_', '', $feed );
 701              $permalink = $wp_rewrite->get_comment_feed_permastruct();
 702          }
 703  
 704          if ( get_default_feed() === $feed ) {
 705              $feed = '';
 706          }
 707  
 708          $permalink = str_replace( '%feed%', $feed, $permalink );
 709          $permalink = preg_replace( '#/+#', '/', "/$permalink" );
 710          $output    = home_url( user_trailingslashit( $permalink, 'feed' ) );
 711      } else {
 712          if ( empty( $feed ) ) {
 713              $feed = get_default_feed();
 714          }
 715  
 716          if ( str_contains( $feed, 'comments_' ) ) {
 717              $feed = str_replace( 'comments_', 'comments-', $feed );
 718          }
 719  
 720          $output = home_url( "?feed={$feed}" );
 721      }
 722  
 723      /**
 724       * Filters the feed type permalink.
 725       *
 726       * @since 1.5.0
 727       *
 728       * @param string $output The feed permalink.
 729       * @param string $feed   The feed type. Possible values include 'rss2', 'atom',
 730       *                       or an empty string for the default feed type.
 731       */
 732      return apply_filters( 'feed_link', $output, $feed );
 733  }
 734  
 735  /**
 736   * Retrieves the permalink for the post comments feed.
 737   *
 738   * @since 2.2.0
 739   *
 740   * @param int    $post_id Optional. Post ID. Default is the ID of the global `$post`.
 741   * @param string $feed    Optional. Feed type. Possible values include 'rss2', 'atom'.
 742   *                        Default is the value of get_default_feed().
 743   * @return string The permalink for the comments feed for the given post on success, empty string on failure.
 744   */
 745  function get_post_comments_feed_link( $post_id = 0, $feed = '' ) {
 746      $post_id = absint( $post_id );
 747  
 748      if ( ! $post_id ) {
 749          $post_id = get_the_ID();
 750      }
 751  
 752      if ( empty( $feed ) ) {
 753          $feed = get_default_feed();
 754      }
 755  
 756      $post = get_post( $post_id );
 757  
 758      // Bail out if the post does not exist.
 759      if ( ! $post instanceof WP_Post ) {
 760          return '';
 761      }
 762  
 763      $unattached = 'attachment' === $post->post_type && 0 === (int) $post->post_parent;
 764  
 765      if ( get_option( 'permalink_structure' ) ) {
 766          if ( 'page' === get_option( 'show_on_front' ) && (int) get_option( 'page_on_front' ) === $post_id ) {
 767              $url = _get_page_link( $post_id );
 768          } else {
 769              $url = get_permalink( $post_id );
 770          }
 771  
 772          if ( $unattached ) {
 773              $url = home_url( '/feed/' );
 774              if ( get_default_feed() !== $feed ) {
 775                  $url .= "$feed/";
 776              }
 777              $url = add_query_arg( 'attachment_id', $post_id, $url );
 778          } else {
 779              $url = trailingslashit( $url ) . 'feed';
 780              if ( get_default_feed() !== $feed ) {
 781                  $url .= "/$feed";
 782              }
 783              $url = user_trailingslashit( $url, 'single_feed' );
 784          }
 785      } else {
 786          if ( $unattached ) {
 787              $url = add_query_arg(
 788                  array(
 789                      'feed'          => $feed,
 790                      'attachment_id' => $post_id,
 791                  ),
 792                  home_url( '/' )
 793              );
 794          } elseif ( 'page' === $post->post_type ) {
 795              $url = add_query_arg(
 796                  array(
 797                      'feed'    => $feed,
 798                      'page_id' => $post_id,
 799                  ),
 800                  home_url( '/' )
 801              );
 802          } else {
 803              $url = add_query_arg(
 804                  array(
 805                      'feed' => $feed,
 806                      'p'    => $post_id,
 807                  ),
 808                  home_url( '/' )
 809              );
 810          }
 811      }
 812  
 813      /**
 814       * Filters the post comments feed permalink.
 815       *
 816       * @since 1.5.1
 817       *
 818       * @param string $url Post comments feed permalink.
 819       */
 820      return apply_filters( 'post_comments_feed_link', $url );
 821  }
 822  
 823  /**
 824   * Displays the comment feed link for a post.
 825   *
 826   * Prints out the comment feed link for a post. Link text is placed in the
 827   * anchor. If no link text is specified, default text is used. If no post ID is
 828   * specified, the current post is used.
 829   *
 830   * @since 2.5.0
 831   *
 832   * @param string $link_text Optional. Descriptive link text. Default 'Comments Feed'.
 833   * @param int    $post_id   Optional. Post ID. Default is the ID of the global `$post`.
 834   * @param string $feed      Optional. Feed type. Possible values include 'rss2', 'atom'.
 835   *                          Default is the value of get_default_feed().
 836   */
 837  function post_comments_feed_link( $link_text = '', $post_id = 0, $feed = '' ) {
 838      $url = get_post_comments_feed_link( $post_id, $feed );
 839      if ( empty( $link_text ) ) {
 840          $link_text = __( 'Comments Feed' );
 841      }
 842  
 843      $link = '<a href="' . esc_url( $url ) . '">' . $link_text . '</a>';
 844      /**
 845       * Filters the post comment feed link anchor tag.
 846       *
 847       * @since 2.8.0
 848       *
 849       * @param string $link    The complete anchor tag for the comment feed link.
 850       * @param int    $post_id Post ID.
 851       * @param string $feed    The feed type. Possible values include 'rss2', 'atom',
 852       *                        or an empty string for the default feed type.
 853       */
 854      echo apply_filters( 'post_comments_feed_link_html', $link, $post_id, $feed );
 855  }
 856  
 857  /**
 858   * Retrieves the feed link for a given author.
 859   *
 860   * Returns a link to the feed for all posts by a given author. A specific feed
 861   * can be requested or left blank to get the default feed.
 862   *
 863   * @since 2.5.0
 864   *
 865   * @param int    $author_id Author ID.
 866   * @param string $feed      Optional. Feed type. Possible values include 'rss2', 'atom'.
 867   *                          Default is the value of get_default_feed().
 868   * @return string Link to the feed for the author specified by $author_id.
 869   */
 870  function get_author_feed_link( $author_id, $feed = '' ) {
 871      $author_id           = (int) $author_id;
 872      $permalink_structure = get_option( 'permalink_structure' );
 873  
 874      if ( empty( $feed ) ) {
 875          $feed = get_default_feed();
 876      }
 877  
 878      if ( ! $permalink_structure ) {
 879          $link = home_url( "?feed=$feed&amp;author=" . $author_id );
 880      } else {
 881          $link = get_author_posts_url( $author_id );
 882          if ( get_default_feed() === $feed ) {
 883              $feed_link = 'feed';
 884          } else {
 885              $feed_link = "feed/$feed";
 886          }
 887  
 888          $link = trailingslashit( $link ) . user_trailingslashit( $feed_link, 'feed' );
 889      }
 890  
 891      /**
 892       * Filters the feed link for a given author.
 893       *
 894       * @since 1.5.1
 895       *
 896       * @param string $link The author feed link.
 897       * @param string $feed Feed type. Possible values include 'rss2', 'atom'.
 898       */
 899      $link = apply_filters( 'author_feed_link', $link, $feed );
 900  
 901      return $link;
 902  }
 903  
 904  /**
 905   * Retrieves the feed link for a category.
 906   *
 907   * Returns a link to the feed for all posts in a given category. A specific feed
 908   * can be requested or left blank to get the default feed.
 909   *
 910   * @since 2.5.0
 911   *
 912   * @param int|WP_Term|object $cat  The ID or category object whose feed link will be retrieved.
 913   * @param string             $feed Optional. Feed type. Possible values include 'rss2', 'atom'.
 914   *                                 Default is the value of get_default_feed().
 915   * @return string Link to the feed for the category specified by `$cat`.
 916   */
 917  function get_category_feed_link( $cat, $feed = '' ) {
 918      return get_term_feed_link( $cat, 'category', $feed );
 919  }
 920  
 921  /**
 922   * Retrieves the feed link for a term.
 923   *
 924   * Returns a link to the feed for all posts in a given term. A specific feed
 925   * can be requested or left blank to get the default feed.
 926   *
 927   * @since 3.0.0
 928   *
 929   * @param int|WP_Term|object $term     The ID or term object whose feed link will be retrieved.
 930   * @param string             $taxonomy Optional. Taxonomy of `$term_id`.
 931   * @param string             $feed     Optional. Feed type. Possible values include 'rss2', 'atom'.
 932   *                                     Default is the value of get_default_feed().
 933   * @return string|false Link to the feed for the term specified by `$term` and `$taxonomy`.
 934   */
 935  function get_term_feed_link( $term, $taxonomy = '', $feed = '' ) {
 936      if ( ! is_object( $term ) ) {
 937          $term = (int) $term;
 938      }
 939  
 940      $term = get_term( $term, $taxonomy );
 941  
 942      if ( empty( $term ) || is_wp_error( $term ) ) {
 943          return false;
 944      }
 945  
 946      $taxonomy = $term->taxonomy;
 947  
 948      if ( empty( $feed ) ) {
 949          $feed = get_default_feed();
 950      }
 951  
 952      $permalink_structure = get_option( 'permalink_structure' );
 953  
 954      if ( ! $permalink_structure ) {
 955          if ( 'category' === $taxonomy ) {
 956              $link = home_url( "?feed=$feed&amp;cat=$term->term_id" );
 957          } elseif ( 'post_tag' === $taxonomy ) {
 958              $link = home_url( "?feed=$feed&amp;tag=$term->slug" );
 959          } else {
 960              $t    = get_taxonomy( $taxonomy );
 961              $link = home_url( "?feed=$feed&amp;$t->query_var=$term->slug" );
 962          }
 963      } else {
 964          $link = get_term_link( $term, $term->taxonomy );
 965          if ( get_default_feed() === $feed ) {
 966              $feed_link = 'feed';
 967          } else {
 968              $feed_link = "feed/$feed";
 969          }
 970  
 971          $link = trailingslashit( $link ) . user_trailingslashit( $feed_link, 'feed' );
 972      }
 973  
 974      if ( 'category' === $taxonomy ) {
 975          /**
 976           * Filters the category feed link.
 977           *
 978           * @since 1.5.1
 979           *
 980           * @param string $link The category feed link.
 981           * @param string $feed Feed type. Possible values include 'rss2', 'atom'.
 982           */
 983          $link = apply_filters( 'category_feed_link', $link, $feed );
 984      } elseif ( 'post_tag' === $taxonomy ) {
 985          /**
 986           * Filters the post tag feed link.
 987           *
 988           * @since 2.3.0
 989           *
 990           * @param string $link The tag feed link.
 991           * @param string $feed Feed type. Possible values include 'rss2', 'atom'.
 992           */
 993          $link = apply_filters( 'tag_feed_link', $link, $feed );
 994      } else {
 995          /**
 996           * Filters the feed link for a taxonomy other than 'category' or 'post_tag'.
 997           *
 998           * @since 3.0.0
 999           *
1000           * @param string $link     The taxonomy feed link.
1001           * @param string $feed     Feed type. Possible values include 'rss2', 'atom'.
1002           * @param string $taxonomy The taxonomy name.
1003           */
1004          $link = apply_filters( 'taxonomy_feed_link', $link, $feed, $taxonomy );
1005      }
1006  
1007      return $link;
1008  }
1009  
1010  /**
1011   * Retrieves the permalink for a tag feed.
1012   *
1013   * @since 2.3.0
1014   *
1015   * @param int|WP_Term|object $tag  The ID or term object whose feed link will be retrieved.
1016   * @param string             $feed Optional. Feed type. Possible values include 'rss2', 'atom'.
1017   *                                 Default is the value of get_default_feed().
1018   * @return string                  The feed permalink for the given tag.
1019   */
1020  function get_tag_feed_link( $tag, $feed = '' ) {
1021      return get_term_feed_link( $tag, 'post_tag', $feed );
1022  }
1023  
1024  /**
1025   * Retrieves the edit link for a tag.
1026   *
1027   * @since 2.7.0
1028   *
1029   * @param int|WP_Term|object $tag      The ID or term object whose edit link will be retrieved.
1030   * @param string             $taxonomy Optional. Taxonomy slug. Default 'post_tag'.
1031   * @return string The edit tag link URL for the given tag.
1032   */
1033  function get_edit_tag_link( $tag, $taxonomy = 'post_tag' ) {
1034      /**
1035       * Filters the edit link for a tag (or term in another taxonomy).
1036       *
1037       * @since 2.7.0
1038       *
1039       * @param string $link The term edit link.
1040       */
1041      return apply_filters( 'get_edit_tag_link', get_edit_term_link( $tag, $taxonomy ) );
1042  }
1043  
1044  /**
1045   * Displays or retrieves the edit link for a tag with formatting.
1046   *
1047   * @since 2.7.0
1048   *
1049   * @param string  $link   Optional. Anchor text. If empty, default is 'Edit This'. Default empty.
1050   * @param string  $before Optional. Display before edit link. Default empty.
1051   * @param string  $after  Optional. Display after edit link. Default empty.
1052   * @param WP_Term $tag    Optional. Term object. If null, the queried object will be inspected.
1053   *                        Default null.
1054   */
1055  function edit_tag_link( $link = '', $before = '', $after = '', $tag = null ) {
1056      $link = edit_term_link( $link, '', '', $tag, false );
1057  
1058      /**
1059       * Filters the anchor tag for the edit link for a tag (or term in another taxonomy).
1060       *
1061       * @since 2.7.0
1062       *
1063       * @param string $link The anchor tag for the edit link.
1064       */
1065      echo $before . apply_filters( 'edit_tag_link', $link ) . $after;
1066  }
1067  
1068  /**
1069   * Retrieves the URL for editing a given term.
1070   *
1071   * @since 3.1.0
1072   * @since 4.5.0 The `$taxonomy` parameter was made optional.
1073   *
1074   * @param int|WP_Term|object $term        The ID or term object whose edit link will be retrieved.
1075   * @param string             $taxonomy    Optional. Taxonomy. Defaults to the taxonomy of the term identified
1076   *                                        by `$term`.
1077   * @param string             $object_type Optional. The object type. Used to highlight the proper post type
1078   *                                        menu on the linked page. Defaults to the first object_type associated
1079   *                                        with the taxonomy.
1080   * @return string|null The edit term link URL for the given term, or null on failure.
1081   */
1082  function get_edit_term_link( $term, $taxonomy = '', $object_type = '' ) {
1083      $term = get_term( $term, $taxonomy );
1084      if ( ! $term || is_wp_error( $term ) ) {
1085          return null;
1086      }
1087  
1088      $tax     = get_taxonomy( $term->taxonomy );
1089      $term_id = $term->term_id;
1090      if ( ! $tax || ! current_user_can( 'edit_term', $term_id ) ) {
1091          return null;
1092      }
1093  
1094      $args = array(
1095          'taxonomy' => $tax->name,
1096          'tag_ID'   => $term_id,
1097      );
1098  
1099      if ( $object_type ) {
1100          $args['post_type'] = $object_type;
1101      } elseif ( ! empty( $tax->object_type ) ) {
1102          $args['post_type'] = reset( $tax->object_type );
1103      }
1104  
1105      if ( $tax->show_ui ) {
1106          $location = add_query_arg( $args, admin_url( 'term.php' ) );
1107      } else {
1108          $location = '';
1109      }
1110  
1111      /**
1112       * Filters the edit link for a term.
1113       *
1114       * @since 3.1.0
1115       *
1116       * @param string $location    The edit link.
1117       * @param int    $term_id     Term ID.
1118       * @param string $taxonomy    Taxonomy name.
1119       * @param string $object_type The object type.
1120       */
1121      return apply_filters( 'get_edit_term_link', $location, $term_id, $taxonomy, $object_type );
1122  }
1123  
1124  /**
1125   * Displays or retrieves the edit term link with formatting.
1126   *
1127   * @since 3.1.0
1128   *
1129   * @param string           $link    Optional. Anchor text. If empty, default is 'Edit This'. Default empty.
1130   * @param string           $before  Optional. Display before edit link. Default empty.
1131   * @param string           $after   Optional. Display after edit link. Default empty.
1132   * @param int|WP_Term|null $term    Optional. Term ID or object. If null, the queried object will be inspected. Default null.
1133   * @param bool             $display Optional. Whether or not to echo the return. Default true.
1134   * @return string|null HTML content.
1135   */
1136  function edit_term_link( $link = '', $before = '', $after = '', $term = null, $display = true ) {
1137      if ( is_null( $term ) ) {
1138          $term = get_queried_object();
1139      } else {
1140          $term = get_term( $term );
1141      }
1142  
1143      if ( ! $term ) {
1144          return null;
1145      }
1146  
1147      if ( ! current_user_can( 'edit_term', $term->term_id ) ) {
1148          return null;
1149      }
1150  
1151      if ( empty( $link ) ) {
1152          $link = __( 'Edit This' );
1153      }
1154  
1155      $link = '<a href="' . get_edit_term_link( $term->term_id, $term->taxonomy ) . '">' . $link . '</a>';
1156  
1157      /**
1158       * Filters the anchor tag for the edit link of a term.
1159       *
1160       * @since 3.1.0
1161       *
1162       * @param string $link    The anchor tag for the edit link.
1163       * @param int    $term_id Term ID.
1164       */
1165      $link = $before . apply_filters( 'edit_term_link', $link, $term->term_id ) . $after;
1166  
1167      if ( ! $display ) {
1168          return $link;
1169      }
1170  
1171      echo $link;
1172  
1173      return null;
1174  }
1175  
1176  /**
1177   * Retrieves the permalink for a search.
1178   *
1179   * @since 3.0.0
1180   *
1181   * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
1182   *
1183   * @param string $query Optional. The query string to use. If empty the current query is used. Default empty.
1184   * @return string The search permalink.
1185   */
1186  function get_search_link( $query = '' ) {
1187      global $wp_rewrite;
1188  
1189      if ( empty( $query ) ) {
1190          $search = get_search_query( false );
1191      } else {
1192          $search = stripslashes( $query );
1193      }
1194  
1195      $permastruct = $wp_rewrite->get_search_permastruct();
1196  
1197      if ( empty( $permastruct ) ) {
1198          $link = home_url( '?s=' . urlencode( $search ) );
1199      } else {
1200          $search = urlencode( $search );
1201          $search = str_replace( '%2F', '/', $search ); // %2F(/) is not valid within a URL, send it un-encoded.
1202          $link   = str_replace( '%search%', $search, $permastruct );
1203          $link   = home_url( user_trailingslashit( $link, 'search' ) );
1204      }
1205  
1206      /**
1207       * Filters the search permalink.
1208       *
1209       * @since 3.0.0
1210       *
1211       * @param string $link   Search permalink.
1212       * @param string $search The URL-encoded search term.
1213       */
1214      return apply_filters( 'search_link', $link, $search );
1215  }
1216  
1217  /**
1218   * Retrieves the permalink for the search results feed.
1219   *
1220   * @since 2.5.0
1221   *
1222   * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
1223   *
1224   * @param string $search_query Optional. Search query. Default empty.
1225   * @param string $feed         Optional. Feed type. Possible values include 'rss2', 'atom'.
1226   *                             Default is the value of get_default_feed().
1227   * @return string The search results feed permalink.
1228   */
1229  function get_search_feed_link( $search_query = '', $feed = '' ) {
1230      global $wp_rewrite;
1231      $link = get_search_link( $search_query );
1232  
1233      if ( empty( $feed ) ) {
1234          $feed = get_default_feed();
1235      }
1236  
1237      $permastruct = $wp_rewrite->get_search_permastruct();
1238  
1239      if ( empty( $permastruct ) ) {
1240          $link = add_query_arg( 'feed', $feed, $link );
1241      } else {
1242          $link  = trailingslashit( $link );
1243          $link .= "feed/$feed/";
1244      }
1245  
1246      /**
1247       * Filters the search feed link.
1248       *
1249       * @since 2.5.0
1250       *
1251       * @param string $link Search feed link.
1252       * @param string $feed Feed type. Possible values include 'rss2', 'atom'.
1253       * @param string $type The search type. One of 'posts' or 'comments'.
1254       */
1255      return apply_filters( 'search_feed_link', $link, $feed, 'posts' );
1256  }
1257  
1258  /**
1259   * Retrieves the permalink for the search results comments feed.
1260   *
1261   * @since 2.5.0
1262   *
1263   * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
1264   *
1265   * @param string $search_query Optional. Search query. Default empty.
1266   * @param string $feed         Optional. Feed type. Possible values include 'rss2', 'atom'.
1267   *                             Default is the value of get_default_feed().
1268   * @return string The comments feed search results permalink.
1269   */
1270  function get_search_comments_feed_link( $search_query = '', $feed = '' ) {
1271      global $wp_rewrite;
1272  
1273      if ( empty( $feed ) ) {
1274          $feed = get_default_feed();
1275      }
1276  
1277      $link = get_search_feed_link( $search_query, $feed );
1278  
1279      $permastruct = $wp_rewrite->get_search_permastruct();
1280  
1281      if ( empty( $permastruct ) ) {
1282          $link = add_query_arg( 'feed', 'comments-' . $feed, $link );
1283      } else {
1284          $link = add_query_arg( 'withcomments', 1, $link );
1285      }
1286  
1287      /** This filter is documented in wp-includes/link-template.php */
1288      return apply_filters( 'search_feed_link', $link, $feed, 'comments' );
1289  }
1290  
1291  /**
1292   * Retrieves the permalink for a post type archive.
1293   *
1294   * @since 3.1.0
1295   * @since 4.5.0 Support for posts was added.
1296   *
1297   * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
1298   *
1299   * @param string $post_type Post type.
1300   * @return string|false The post type archive permalink. False if the post type
1301   *                      does not exist or does not have an archive.
1302   */
1303  function get_post_type_archive_link( $post_type ) {
1304      global $wp_rewrite;
1305  
1306      $post_type_obj = get_post_type_object( $post_type );
1307  
1308      if ( ! $post_type_obj ) {
1309          return false;
1310      }
1311  
1312      if ( 'post' === $post_type ) {
1313          $show_on_front  = get_option( 'show_on_front' );
1314          $page_for_posts = get_option( 'page_for_posts' );
1315  
1316          if ( 'page' === $show_on_front && $page_for_posts ) {
1317              $link = get_permalink( $page_for_posts );
1318          } else {
1319              $link = get_home_url();
1320          }
1321          /** This filter is documented in wp-includes/link-template.php */
1322          return apply_filters( 'post_type_archive_link', $link, $post_type );
1323      }
1324  
1325      if ( ! $post_type_obj->has_archive ) {
1326          return false;
1327      }
1328  
1329      if ( get_option( 'permalink_structure' ) && is_array( $post_type_obj->rewrite ) ) {
1330          $struct = ( true === $post_type_obj->has_archive ) ? $post_type_obj->rewrite['slug'] : $post_type_obj->has_archive;
1331          if ( $post_type_obj->rewrite['with_front'] ) {
1332              $struct = $wp_rewrite->front . $struct;
1333          } else {
1334              $struct = $wp_rewrite->root . $struct;
1335          }
1336          $link = home_url( user_trailingslashit( $struct, 'post_type_archive' ) );
1337      } else {
1338          $link = home_url( '?post_type=' . $post_type );
1339      }
1340  
1341      /**
1342       * Filters the post type archive permalink.
1343       *
1344       * @since 3.1.0
1345       *
1346       * @param string $link      The post type archive permalink.
1347       * @param string $post_type Post type name.
1348       */
1349      return apply_filters( 'post_type_archive_link', $link, $post_type );
1350  }
1351  
1352  /**
1353   * Retrieves the permalink for a post type archive feed.
1354   *
1355   * @since 3.1.0
1356   *
1357   * @param string $post_type Post type.
1358   * @param string $feed      Optional. Feed type. Possible values include 'rss2', 'atom'.
1359   *                          Default is the value of get_default_feed().
1360   * @return string|false The post type feed permalink. False if the post type
1361   *                      does not exist or does not have an archive.
1362   */
1363  function get_post_type_archive_feed_link( $post_type, $feed = '' ) {
1364      $default_feed = get_default_feed();
1365      if ( empty( $feed ) ) {
1366          $feed = $default_feed;
1367      }
1368  
1369      $link = get_post_type_archive_link( $post_type );
1370      if ( ! $link ) {
1371          return false;
1372      }
1373  
1374      $post_type_obj = get_post_type_object( $post_type );
1375      if ( get_option( 'permalink_structure' ) && is_array( $post_type_obj->rewrite ) && $post_type_obj->rewrite['feeds'] ) {
1376          $link  = trailingslashit( $link );
1377          $link .= 'feed/';
1378          if ( $feed !== $default_feed ) {
1379              $link .= "$feed/";
1380          }
1381      } else {
1382          $link = add_query_arg( 'feed', $feed, $link );
1383      }
1384  
1385      /**
1386       * Filters the post type archive feed link.
1387       *
1388       * @since 3.1.0
1389       *
1390       * @param string $link The post type archive feed link.
1391       * @param string $feed Feed type. Possible values include 'rss2', 'atom'.
1392       */
1393      return apply_filters( 'post_type_archive_feed_link', $link, $feed );
1394  }
1395  
1396  /**
1397   * Retrieves the URL used for the post preview.
1398   *
1399   * Allows additional query args to be appended.
1400   *
1401   * @since 4.4.0
1402   *
1403   * @param int|WP_Post $post         Optional. Post ID or `WP_Post` object. Defaults to global `$post`.
1404   * @param array       $query_args   Optional. Array of additional query args to be appended to the link.
1405   *                                  Default empty array.
1406   * @param string      $preview_link Optional. Base preview link to be used if it should differ from the
1407   *                                  post permalink. Default empty.
1408   * @return string|null URL used for the post preview, or null if the post does not exist.
1409   */
1410  function get_preview_post_link( $post = null, $query_args = array(), $preview_link = '' ) {
1411      $post = get_post( $post );
1412  
1413      if ( ! $post ) {
1414          return null;
1415      }
1416  
1417      $post_type_object = get_post_type_object( $post->post_type );
1418      if ( is_post_type_viewable( $post_type_object ) ) {
1419          if ( ! $preview_link ) {
1420              $preview_link = set_url_scheme( get_permalink( $post ) );
1421          }
1422  
1423          $query_args['preview'] = 'true';
1424          $preview_link          = add_query_arg( $query_args, $preview_link );
1425      }
1426  
1427      /**
1428       * Filters the URL used for a post preview.
1429       *
1430       * @since 2.0.5
1431       * @since 4.0.0 Added the `$post` parameter.
1432       *
1433       * @param string  $preview_link URL used for the post preview.
1434       * @param WP_Post $post         Post object.
1435       */
1436      return apply_filters( 'preview_post_link', $preview_link, $post );
1437  }
1438  
1439  /**
1440   * Retrieves the edit post link for post.
1441   *
1442   * Can be used within the WordPress loop or outside of it. Can be used with
1443   * pages, posts, attachments, revisions, global styles, templates, and template parts.
1444   *
1445   * @since 2.3.0
1446   * @since 6.3.0 Adds custom link for wp_navigation post types.
1447   *              Adds custom links for wp_template_part and wp_template post types.
1448   *
1449   * @param int|WP_Post $post    Optional. Post ID or post object. Default is the global `$post`.
1450   * @param string      $context Optional. How to output the '&' character. Default '&amp;'.
1451   * @return string|null The edit post link for the given post. Null if the post type does not exist
1452   *                     or does not allow an editing UI.
1453   */
1454  function get_edit_post_link( $post = 0, $context = 'display' ) {
1455      $post = get_post( $post );
1456  
1457      if ( ! $post ) {
1458          return null;
1459      }
1460  
1461      if ( 'revision' === $post->post_type ) {
1462          $action = '';
1463      } elseif ( 'display' === $context ) {
1464          $action = '&amp;action=edit';
1465      } else {
1466          $action = '&action=edit';
1467      }
1468  
1469      $post_type_object = get_post_type_object( $post->post_type );
1470  
1471      if ( ! $post_type_object ) {
1472          return null;
1473      }
1474  
1475      if ( ! current_user_can( 'edit_post', $post->ID ) ) {
1476          return null;
1477      }
1478  
1479      $link = '';
1480  
1481      if ( 'wp_template' === $post->post_type || 'wp_template_part' === $post->post_type ) {
1482          $slug = urlencode( get_stylesheet() . '//' . $post->post_name );
1483          $link = admin_url( sprintf( $post_type_object->_edit_link, $post->post_type, $slug ) );
1484      } elseif ( 'wp_navigation' === $post->post_type ) {
1485          $link = admin_url( sprintf( $post_type_object->_edit_link, (string) $post->ID ) );
1486      } elseif ( $post_type_object->_edit_link ) {
1487          $link = admin_url( sprintf( $post_type_object->_edit_link . $action, $post->ID ) );
1488      }
1489  
1490      /**
1491       * Filters the post edit link.
1492       *
1493       * @since 2.3.0
1494       *
1495       * @param string $link    The edit link.
1496       * @param int    $post_id Post ID.
1497       * @param string $context The link context. If set to 'display' then ampersands
1498       *                        are encoded.
1499       */
1500      return apply_filters( 'get_edit_post_link', $link, $post->ID, $context );
1501  }
1502  
1503  /**
1504   * Displays the edit post link for post.
1505   *
1506   * @since 1.0.0
1507   * @since 4.4.0 The `$css_class` argument was added.
1508   *
1509   * @param string      $text      Optional. Anchor text. If null, default is 'Edit This'. Default null.
1510   * @param string      $before    Optional. Display before edit link. Default empty.
1511   * @param string      $after     Optional. Display after edit link. Default empty.
1512   * @param int|WP_Post $post      Optional. Post ID or post object. Default is the global `$post`.
1513   * @param string      $css_class Optional. Add custom class to link. Default 'post-edit-link'.
1514   */
1515  function edit_post_link( $text = null, $before = '', $after = '', $post = 0, $css_class = 'post-edit-link' ) {
1516      $post = get_post( $post );
1517  
1518      if ( ! $post ) {
1519          return;
1520      }
1521  
1522      $url = get_edit_post_link( $post->ID );
1523  
1524      if ( ! $url ) {
1525          return;
1526      }
1527  
1528      if ( null === $text ) {
1529          $text = __( 'Edit This' );
1530      }
1531  
1532      $link = '<a class="' . esc_attr( $css_class ) . '" href="' . esc_url( $url ) . '">' . $text . '</a>';
1533  
1534      /**
1535       * Filters the post edit link anchor tag.
1536       *
1537       * @since 2.3.0
1538       *
1539       * @param string $link    Anchor tag for the edit link.
1540       * @param int    $post_id Post ID.
1541       * @param string $text    Anchor text.
1542       */
1543      echo $before . apply_filters( 'edit_post_link', $link, $post->ID, $text ) . $after;
1544  }
1545  
1546  /**
1547   * Retrieves the delete posts link for post.
1548   *
1549   * Can be used within the WordPress loop or outside of it, with any post type.
1550   *
1551   * @since 2.9.0
1552   *
1553   * @param int|WP_Post $post         Optional. Post ID or post object. Default is the global `$post`.
1554   * @param string      $deprecated   Not used.
1555   * @param bool        $force_delete Optional. Whether to bypass Trash and force deletion. Default false.
1556   * @return string|null The delete post link URL for the given post.
1557   */
1558  function get_delete_post_link( $post = 0, $deprecated = '', $force_delete = false ) {
1559      if ( ! empty( $deprecated ) ) {
1560          _deprecated_argument( __FUNCTION__, '3.0.0' );
1561      }
1562  
1563      $post = get_post( $post );
1564  
1565      if ( ! $post ) {
1566          return null;
1567      }
1568  
1569      $post_type_object = get_post_type_object( $post->post_type );
1570  
1571      if ( ! $post_type_object ) {
1572          return null;
1573      }
1574  
1575      if ( ! current_user_can( 'delete_post', $post->ID ) ) {
1576          return null;
1577      }
1578  
1579      $action = ( $force_delete || ! EMPTY_TRASH_DAYS ) ? 'delete' : 'trash';
1580  
1581      $delete_link = add_query_arg( 'action', $action, admin_url( sprintf( $post_type_object->_edit_link, $post->ID ) ) );
1582  
1583      /**
1584       * Filters the post delete link.
1585       *
1586       * @since 2.9.0
1587       *
1588       * @param string $link         The delete link.
1589       * @param int    $post_id      Post ID.
1590       * @param bool   $force_delete Whether to bypass the Trash and force deletion. Default false.
1591       */
1592      return apply_filters( 'get_delete_post_link', wp_nonce_url( $delete_link, "$action-post_{$post->ID}" ), $post->ID, $force_delete );
1593  }
1594  
1595  /**
1596   * Retrieves the edit comment link.
1597   *
1598   * @since 2.3.0
1599   * @since 6.7.0 The $context parameter was added.
1600   *
1601   * @param int|WP_Comment $comment_id Optional. Comment ID or WP_Comment object.
1602   * @param string         $context    Optional. Context in which the URL should be used. Either 'display',
1603   *                                   to include HTML entities, or 'url'. Default 'display'.
1604   * @return string|null The edit comment link URL for the given comment, or null if the comment does not exist or
1605   *                     the current user is not allowed to edit it.
1606   */
1607  function get_edit_comment_link( $comment_id = 0, $context = 'display' ) {
1608      $comment = get_comment( $comment_id );
1609  
1610      if ( ! is_object( $comment ) || ! current_user_can( 'edit_comment', $comment->comment_ID ) ) {
1611          return null;
1612      }
1613  
1614      if ( 'display' === $context ) {
1615          $action = 'comment.php?action=editcomment&amp;c=';
1616      } else {
1617          $action = 'comment.php?action=editcomment&c=';
1618      }
1619  
1620      $location = admin_url( $action ) . $comment->comment_ID;
1621  
1622      // Ensure the $comment_id variable passed to the filter is always an ID.
1623      $comment_id = (int) $comment->comment_ID;
1624  
1625      /**
1626       * Filters the comment edit link.
1627       *
1628       * @since 2.3.0
1629       * @since 6.7.0 The `$comment_id` and `$context` parameters are now being passed to the filter.
1630       *
1631       * @param string $location   The edit link.
1632       * @param int    $comment_id Unique ID of the comment to generate an edit link.
1633       * @param string $context    Context to include HTML entities in link. Default 'display'.
1634       */
1635      return apply_filters( 'get_edit_comment_link', $location, $comment_id, $context );
1636  }
1637  
1638  /**
1639   * Displays the edit comment link with formatting.
1640   *
1641   * @since 1.0.0
1642   *
1643   * @param string $text   Optional. Anchor text. If null, default is 'Edit This'. Default null.
1644   * @param string $before Optional. Display before edit link. Default empty.
1645   * @param string $after  Optional. Display after edit link. Default empty.
1646   */
1647  function edit_comment_link( $text = null, $before = '', $after = '' ) {
1648      $comment = get_comment();
1649  
1650      if ( ! current_user_can( 'edit_comment', $comment->comment_ID ) ) {
1651          return;
1652      }
1653  
1654      if ( null === $text ) {
1655          $text = __( 'Edit This' );
1656      }
1657  
1658      $link = '<a class="comment-edit-link" href="' . esc_url( get_edit_comment_link( $comment ) ) . '">' . $text . '</a>';
1659  
1660      /**
1661       * Filters the comment edit link anchor tag.
1662       *
1663       * @since 2.3.0
1664       *
1665       * @param string $link       Anchor tag for the edit link.
1666       * @param string $comment_id Comment ID as a numeric string.
1667       * @param string $text       Anchor text.
1668       */
1669      echo $before . apply_filters( 'edit_comment_link', $link, $comment->comment_ID, $text ) . $after;
1670  }
1671  
1672  /**
1673   * Displays the edit bookmark link.
1674   *
1675   * @since 2.7.0
1676   *
1677   * @param int|stdClass $link Optional. Bookmark ID. Default is the ID of the current bookmark.
1678   * @return string|null The edit bookmark link URL.
1679   */
1680  function get_edit_bookmark_link( $link = 0 ) {
1681      $link = get_bookmark( $link );
1682  
1683      if ( ! current_user_can( 'manage_links' ) ) {
1684          return null;
1685      }
1686  
1687      $location = admin_url( 'link.php?action=edit&amp;link_id=' ) . $link->link_id;
1688  
1689      /**
1690       * Filters the bookmark edit link.
1691       *
1692       * @since 2.7.0
1693       *
1694       * @param string $location The edit link.
1695       * @param int    $link_id  Bookmark ID.
1696       */
1697      return apply_filters( 'get_edit_bookmark_link', $location, $link->link_id );
1698  }
1699  
1700  /**
1701   * Displays the edit bookmark link anchor content.
1702   *
1703   * @since 2.7.0
1704   *
1705   * @param string $link     Optional. Anchor text. If empty, default is 'Edit This'. Default empty.
1706   * @param string $before   Optional. Display before edit link. Default empty.
1707   * @param string $after    Optional. Display after edit link. Default empty.
1708   * @param int    $bookmark Optional. Bookmark ID. Default is the current bookmark.
1709   */
1710  function edit_bookmark_link( $link = '', $before = '', $after = '', $bookmark = null ) {
1711      $bookmark = get_bookmark( $bookmark );
1712  
1713      if ( ! current_user_can( 'manage_links' ) ) {
1714          return;
1715      }
1716  
1717      if ( empty( $link ) ) {
1718          $link = __( 'Edit This' );
1719      }
1720  
1721      $link = '<a href="' . esc_url( get_edit_bookmark_link( $bookmark ) ) . '">' . $link . '</a>';
1722  
1723      /**
1724       * Filters the bookmark edit link anchor tag.
1725       *
1726       * @since 2.7.0
1727       *
1728       * @param string $link    Anchor tag for the edit link.
1729       * @param int    $link_id Bookmark ID.
1730       */
1731      echo $before . apply_filters( 'edit_bookmark_link', $link, $bookmark->link_id ) . $after;
1732  }
1733  
1734  /**
1735   * Retrieves the edit user link.
1736   *
1737   * @since 3.5.0
1738   *
1739   * @param int $user_id Optional. User ID. Defaults to the current user.
1740   * @return string URL to edit user page or empty string.
1741   */
1742  function get_edit_user_link( $user_id = null ) {
1743      if ( ! $user_id ) {
1744          $user_id = get_current_user_id();
1745      }
1746  
1747      if ( empty( $user_id ) || ! current_user_can( 'edit_user', $user_id ) ) {
1748          return '';
1749      }
1750  
1751      $user = get_userdata( $user_id );
1752  
1753      if ( ! $user ) {
1754          return '';
1755      }
1756  
1757      if ( get_current_user_id() === $user->ID ) {
1758          $link = get_edit_profile_url( $user->ID );
1759      } else {
1760          $link = add_query_arg( 'user_id', $user->ID, self_admin_url( 'user-edit.php' ) );
1761      }
1762  
1763      /**
1764       * Filters the user edit link.
1765       *
1766       * @since 3.5.0
1767       *
1768       * @param string $link    The edit link.
1769       * @param int    $user_id User ID.
1770       */
1771      return apply_filters( 'get_edit_user_link', $link, $user->ID );
1772  }
1773  
1774  //
1775  // Navigation links.
1776  //
1777  
1778  /**
1779   * Retrieves the previous post that is adjacent to the current post.
1780   *
1781   * @since 1.5.0
1782   *
1783   * @param bool         $in_same_term   Optional. Whether post should be in the same taxonomy term.
1784   *                                     Default false.
1785   * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs.
1786   *                                     Default empty.
1787   * @param string       $taxonomy       Optional. Taxonomy, if `$in_same_term` is true. Default 'category'.
1788   * @return WP_Post|null|string Post object if successful. Null if global `$post` is not set.
1789   *                             Empty string if no corresponding post exists.
1790   */
1791  function get_previous_post( $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
1792      return get_adjacent_post( $in_same_term, $excluded_terms, true, $taxonomy );
1793  }
1794  
1795  /**
1796   * Retrieves the next post that is adjacent to the current post.
1797   *
1798   * @since 1.5.0
1799   *
1800   * @param bool         $in_same_term   Optional. Whether post should be in the same taxonomy term.
1801   *                                     Default false.
1802   * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs.
1803   *                                     Default empty.
1804   * @param string       $taxonomy       Optional. Taxonomy, if `$in_same_term` is true. Default 'category'.
1805   * @return WP_Post|null|string Post object if successful. Null if global `$post` is not set.
1806   *                             Empty string if no corresponding post exists.
1807   */
1808  function get_next_post( $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
1809      return get_adjacent_post( $in_same_term, $excluded_terms, false, $taxonomy );
1810  }
1811  
1812  /**
1813   * Retrieves the adjacent post.
1814   *
1815   * Can either be next or previous post.
1816   *
1817   * @since 2.5.0
1818   *
1819   * @global wpdb $wpdb WordPress database abstraction object.
1820   *
1821   * @param bool         $in_same_term   Optional. Whether post should be in the same taxonomy term.
1822   *                                     Default false.
1823   * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs.
1824   *                                     Default empty string.
1825   * @param bool         $previous       Optional. Whether to retrieve previous post.
1826   *                                     Default true.
1827   * @param string       $taxonomy       Optional. Taxonomy, if `$in_same_term` is true. Default 'category'.
1828   * @return WP_Post|null|string Post object if successful. Null if global `$post` is not set.
1829   *                             Empty string if no corresponding post exists.
1830   */
1831  function get_adjacent_post( $in_same_term = false, $excluded_terms = '', $previous = true, $taxonomy = 'category' ) {
1832      global $wpdb;
1833  
1834      $post = get_post();
1835  
1836      if ( ! $post || ! taxonomy_exists( $taxonomy ) ) {
1837          return null;
1838      }
1839  
1840      $current_post_date = $post->post_date;
1841  
1842      $join     = '';
1843      $where    = '';
1844      $adjacent = $previous ? 'previous' : 'next';
1845  
1846      if ( ! empty( $excluded_terms ) && ! is_array( $excluded_terms ) ) {
1847          // Back-compat, $excluded_terms used to be $excluded_categories with IDs separated by " and ".
1848          if ( str_contains( $excluded_terms, ' and ' ) ) {
1849              _deprecated_argument(
1850                  __FUNCTION__,
1851                  '3.3.0',
1852                  sprintf(
1853                      /* translators: %s: The word 'and'. */
1854                      __( 'Use commas instead of %s to separate excluded terms.' ),
1855                      "'and'"
1856                  )
1857              );
1858              $excluded_terms = explode( ' and ', $excluded_terms );
1859          } else {
1860              $excluded_terms = explode( ',', $excluded_terms );
1861          }
1862  
1863          $excluded_terms = array_map( 'intval', $excluded_terms );
1864      }
1865  
1866      /**
1867       * Filters the IDs of terms excluded from adjacent post queries.
1868       *
1869       * The dynamic portion of the hook name, `$adjacent`, refers to the type
1870       * of adjacency, 'next' or 'previous'.
1871       *
1872       * Possible hook names include:
1873       *
1874       *  - `get_next_post_excluded_terms`
1875       *  - `get_previous_post_excluded_terms`
1876       *
1877       * @since 4.4.0
1878       *
1879       * @param int[]|string $excluded_terms Array of excluded term IDs. Empty string if none were provided.
1880       */
1881      $excluded_terms = apply_filters( "get_{$adjacent}_post_excluded_terms", $excluded_terms );
1882  
1883      if ( $in_same_term || ! empty( $excluded_terms ) ) {
1884          if ( $in_same_term ) {
1885              $join  .= " INNER JOIN $wpdb->term_relationships AS tr ON p.ID = tr.object_id INNER JOIN $wpdb->term_taxonomy AS tt ON tr.term_taxonomy_id = tt.term_taxonomy_id";
1886              $where .= $wpdb->prepare( 'AND tt.taxonomy = %s', $taxonomy );
1887  
1888              if ( ! is_object_in_taxonomy( $post->post_type, $taxonomy ) ) {
1889                  return '';
1890              }
1891              $term_array = wp_get_object_terms( $post->ID, $taxonomy, array( 'fields' => 'ids' ) );
1892              if ( is_wp_error( $term_array ) ) {
1893                  return '';
1894              }
1895  
1896              // Remove any exclusions from the term array to include.
1897              $term_array = array_diff( $term_array, (array) $excluded_terms );
1898  
1899              if ( ! $term_array ) {
1900                  return '';
1901              }
1902  
1903              $term_array = array_map( 'intval', $term_array );
1904  
1905              $where .= ' AND tt.term_id IN (' . implode( ',', $term_array ) . ')';
1906          }
1907  
1908          if ( ! empty( $excluded_terms ) ) {
1909              $where .= " AND p.ID NOT IN ( SELECT tr.object_id FROM $wpdb->term_relationships tr LEFT JOIN $wpdb->term_taxonomy tt ON (tr.term_taxonomy_id = tt.term_taxonomy_id) WHERE tt.term_id IN (" . implode( ',', array_map( 'intval', $excluded_terms ) ) . ') )';
1910          }
1911      }
1912  
1913      // 'post_status' clause depends on the current user.
1914      if ( is_user_logged_in() ) {
1915          $user_id = get_current_user_id();
1916  
1917          $post_type_object = get_post_type_object( $post->post_type );
1918          if ( empty( $post_type_object ) ) {
1919              $post_type_cap    = $post->post_type;
1920              $read_private_cap = 'read_private_' . $post_type_cap . 's';
1921          } else {
1922              $read_private_cap = $post_type_object->cap->read_private_posts;
1923          }
1924  
1925          /*
1926           * Results should include private posts belonging to the current user, or private posts where the
1927           * current user has the 'read_private_posts' cap.
1928           */
1929          $private_states = get_post_stati( array( 'private' => true ) );
1930          $where         .= " AND ( p.post_status = 'publish'";
1931          foreach ( $private_states as $state ) {
1932              if ( current_user_can( $read_private_cap ) ) {
1933                  $where .= $wpdb->prepare( ' OR p.post_status = %s', $state );
1934              } else {
1935                  $where .= $wpdb->prepare( ' OR (p.post_author = %d AND p.post_status = %s)', $user_id, $state );
1936              }
1937          }
1938          $where .= ' )';
1939      } else {
1940          $where .= " AND p.post_status = 'publish'";
1941      }
1942  
1943      $comparison_operator = $previous ? '<' : '>';
1944      $order               = $previous ? 'DESC' : 'ASC';
1945  
1946      /**
1947       * Filters the JOIN clause in the SQL for an adjacent post query.
1948       *
1949       * The dynamic portion of the hook name, `$adjacent`, refers to the type
1950       * of adjacency, 'next' or 'previous'.
1951       *
1952       * Possible hook names include:
1953       *
1954       *  - `get_next_post_join`
1955       *  - `get_previous_post_join`
1956       *
1957       * @since 2.5.0
1958       * @since 4.4.0 Added the `$taxonomy` and `$post` parameters.
1959       *
1960       * @param string       $join           The JOIN clause in the SQL.
1961       * @param bool         $in_same_term   Whether post should be in the same taxonomy term.
1962       * @param int[]|string $excluded_terms Array of excluded term IDs. Empty string if none were provided.
1963       * @param string       $taxonomy       Taxonomy. Used to identify the term used when `$in_same_term` is true.
1964       * @param WP_Post      $post           WP_Post object.
1965       */
1966      $join = apply_filters( "get_{$adjacent}_post_join", $join, $in_same_term, $excluded_terms, $taxonomy, $post );
1967  
1968      // Prepare the where clause for the adjacent post query.
1969      $where_prepared = $wpdb->prepare( "WHERE (p.post_date $comparison_operator %s OR (p.post_date = %s AND p.ID $comparison_operator %d)) AND p.post_type = %s $where", $current_post_date, $current_post_date, $post->ID, $post->post_type ); // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- $comparison_operator is a string literal, either '<' or '>'.
1970  
1971      /**
1972       * Filters the WHERE clause in the SQL for an adjacent post query.
1973       *
1974       * The dynamic portion of the hook name, `$adjacent`, refers to the type
1975       * of adjacency, 'next' or 'previous'.
1976       *
1977       * Possible hook names include:
1978       *
1979       *  - `get_next_post_where`
1980       *  - `get_previous_post_where`
1981       *
1982       * @since 2.5.0
1983       * @since 4.4.0 Added the `$taxonomy` and `$post` parameters.
1984       * @since 6.9.0 Adds ID-based fallback for posts with identical dates in adjacent post queries.
1985       *
1986       * @param string       $where          The `WHERE` clause in the SQL.
1987       * @param bool         $in_same_term   Whether post should be in the same taxonomy term.
1988       * @param int[]|string $excluded_terms Array of excluded term IDs. Empty string if none were provided.
1989       * @param string       $taxonomy       Taxonomy. Used to identify the term used when `$in_same_term` is true.
1990       * @param WP_Post      $post           WP_Post object.
1991       */
1992      $where = apply_filters( "get_{$adjacent}_post_where", $where_prepared, $in_same_term, $excluded_terms, $taxonomy, $post );
1993  
1994      /**
1995       * Filters the ORDER BY clause in the SQL for an adjacent post query.
1996       *
1997       * The dynamic portion of the hook name, `$adjacent`, refers to the type
1998       * of adjacency, 'next' or 'previous'.
1999       *
2000       * Possible hook names include:
2001       *
2002       *  - `get_next_post_sort`
2003       *  - `get_previous_post_sort`
2004       *
2005       * @since 2.5.0
2006       * @since 4.4.0 Added the `$post` parameter.
2007       * @since 4.9.0 Added the `$order` parameter.
2008       * @since 6.9.0 Adds ID sort to ensure deterministic ordering for posts with identical dates.
2009       *
2010       * @param string $order_by The `ORDER BY` clause in the SQL.
2011       * @param WP_Post $post    WP_Post object.
2012       * @param string  $order   Sort order. 'DESC' for previous post, 'ASC' for next.
2013       */
2014      $sort = apply_filters( "get_{$adjacent}_post_sort", "ORDER BY p.post_date $order, p.ID $order LIMIT 1", $post, $order );
2015  
2016      $query        = "SELECT p.ID FROM $wpdb->posts AS p $join $where $sort";
2017      $key          = md5( $query );
2018      $last_changed = (array) wp_cache_get_last_changed( 'posts' );
2019      if ( $in_same_term || ! empty( $excluded_terms ) ) {
2020          $last_changed[] = wp_cache_get_last_changed( 'terms' );
2021      }
2022      $cache_key = "adjacent_post:$key";
2023  
2024      $result = wp_cache_get_salted( $cache_key, 'post-queries', $last_changed );
2025      if ( false !== $result ) {
2026          if ( $result ) {
2027              $result = get_post( $result );
2028          }
2029          return $result;
2030      }
2031  
2032      $result = $wpdb->get_var( $query );
2033      if ( null === $result ) {
2034          $result = '';
2035      }
2036  
2037      wp_cache_set_salted( $cache_key, $result, 'post-queries', $last_changed );
2038  
2039      if ( $result ) {
2040          $result = get_post( $result );
2041      }
2042  
2043      return $result;
2044  }
2045  
2046  /**
2047   * Retrieves the adjacent post relational link.
2048   *
2049   * Can either be next or previous post relational link.
2050   *
2051   * @since 2.8.0
2052   *
2053   * @param string       $title          Optional. Link title format. Default '%title'.
2054   * @param bool         $in_same_term   Optional. Whether link should be in the same taxonomy term.
2055   *                                     Default false.
2056   * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs.
2057   *                                     Default empty.
2058   * @param bool         $previous       Optional. Whether to display link to previous or next post.
2059   *                                     Default true.
2060   * @param string       $taxonomy       Optional. Taxonomy, if `$in_same_term` is true. Default 'category'.
2061   * @return string|null The adjacent post relational link URL.
2062   */
2063  function get_adjacent_post_rel_link( $title = '%title', $in_same_term = false, $excluded_terms = '', $previous = true, $taxonomy = 'category' ) {
2064      $post = get_post();
2065      if ( $previous && is_attachment() && $post ) {
2066          $post = get_post( $post->post_parent );
2067      } else {
2068          $post = get_adjacent_post( $in_same_term, $excluded_terms, $previous, $taxonomy );
2069      }
2070  
2071      if ( empty( $post ) ) {
2072          return null;
2073      }
2074  
2075      $post_title = the_title_attribute(
2076          array(
2077              'echo' => false,
2078              'post' => $post,
2079          )
2080      );
2081  
2082      if ( empty( $post_title ) ) {
2083          $post_title = $previous ? __( 'Previous Post' ) : __( 'Next Post' );
2084      }
2085  
2086      $date = mysql2date( get_option( 'date_format' ), $post->post_date );
2087  
2088      $title = str_replace( '%title', $post_title, $title );
2089      $title = str_replace( '%date', $date, $title );
2090  
2091      $link  = $previous ? "<link rel='prev' title='" : "<link rel='next' title='";
2092      $link .= esc_attr( $title );
2093      $link .= "' href='" . get_permalink( $post ) . "' />\n";
2094  
2095      $adjacent = $previous ? 'previous' : 'next';
2096  
2097      /**
2098       * Filters the adjacent post relational link.
2099       *
2100       * The dynamic portion of the hook name, `$adjacent`, refers to the type
2101       * of adjacency, 'next' or 'previous'.
2102       *
2103       * Possible hook names include:
2104       *
2105       *  - `next_post_rel_link`
2106       *  - `previous_post_rel_link`
2107       *
2108       * @since 2.8.0
2109       *
2110       * @param string $link The relational link.
2111       */
2112      return apply_filters( "{$adjacent}_post_rel_link", $link );
2113  }
2114  
2115  /**
2116   * Displays the relational links for the posts adjacent to the current post.
2117   *
2118   * @since 2.8.0
2119   *
2120   * @param string       $title          Optional. Link title format. Default '%title'.
2121   * @param bool         $in_same_term   Optional. Whether link should be in the same taxonomy term.
2122   *                                     Default false.
2123   * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs.
2124   *                                     Default empty.
2125   * @param string       $taxonomy       Optional. Taxonomy, if `$in_same_term` is true. Default 'category'.
2126   */
2127  function adjacent_posts_rel_link( $title = '%title', $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
2128      echo get_adjacent_post_rel_link( $title, $in_same_term, $excluded_terms, true, $taxonomy );
2129      echo get_adjacent_post_rel_link( $title, $in_same_term, $excluded_terms, false, $taxonomy );
2130  }
2131  
2132  /**
2133   * Displays relational links for the posts adjacent to the current post for single post pages.
2134   *
2135   * This is meant to be attached to actions like 'wp_head'. Do not call this directly in plugins
2136   * or theme templates.
2137   *
2138   * @since 3.0.0
2139   * @since 5.6.0 No longer used in core.
2140   *
2141   * @see adjacent_posts_rel_link()
2142   */
2143  function adjacent_posts_rel_link_wp_head() {
2144      if ( ! is_single() || is_attachment() ) {
2145          return;
2146      }
2147      adjacent_posts_rel_link();
2148  }
2149  
2150  /**
2151   * Displays the relational link for the next post adjacent to the current post.
2152   *
2153   * @since 2.8.0
2154   *
2155   * @see get_adjacent_post_rel_link()
2156   *
2157   * @param string       $title          Optional. Link title format. Default '%title'.
2158   * @param bool         $in_same_term   Optional. Whether link should be in the same taxonomy term.
2159   *                                     Default false.
2160   * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs.
2161   *                                     Default empty.
2162   * @param string       $taxonomy       Optional. Taxonomy, if `$in_same_term` is true. Default 'category'.
2163   */
2164  function next_post_rel_link( $title = '%title', $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
2165      echo get_adjacent_post_rel_link( $title, $in_same_term, $excluded_terms, false, $taxonomy );
2166  }
2167  
2168  /**
2169   * Displays the relational link for the previous post adjacent to the current post.
2170   *
2171   * @since 2.8.0
2172   *
2173   * @see get_adjacent_post_rel_link()
2174   *
2175   * @param string       $title          Optional. Link title format. Default '%title'.
2176   * @param bool         $in_same_term   Optional. Whether link should be in the same taxonomy term.
2177   *                                     Default false.
2178   * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs.
2179   *                                     Default true.
2180   * @param string       $taxonomy       Optional. Taxonomy, if `$in_same_term` is true. Default 'category'.
2181   */
2182  function prev_post_rel_link( $title = '%title', $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
2183      echo get_adjacent_post_rel_link( $title, $in_same_term, $excluded_terms, true, $taxonomy );
2184  }
2185  
2186  /**
2187   * Retrieves the boundary post.
2188   *
2189   * Boundary being either the first or last post by publish date within the constraints specified
2190   * by `$in_same_term` or `$excluded_terms`.
2191   *
2192   * @since 2.8.0
2193   *
2194   * @param bool         $in_same_term   Optional. Whether returned post should be in the same taxonomy term.
2195   *                                     Default false.
2196   * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs.
2197   *                                     Default empty.
2198   * @param bool         $start          Optional. Whether to retrieve first or last post.
2199   *                                     Default true.
2200   * @param string       $taxonomy       Optional. Taxonomy, if `$in_same_term` is true. Default 'category'.
2201   * @return array|null Array containing the boundary post object if successful, null otherwise.
2202   */
2203  function get_boundary_post( $in_same_term = false, $excluded_terms = '', $start = true, $taxonomy = 'category' ) {
2204      $post = get_post();
2205  
2206      if ( ! $post || ! is_single() || is_attachment() || ! taxonomy_exists( $taxonomy ) ) {
2207          return null;
2208      }
2209  
2210      $query_args = array(
2211          'posts_per_page'         => 1,
2212          'order'                  => $start ? 'ASC' : 'DESC',
2213          'update_post_term_cache' => false,
2214          'update_post_meta_cache' => false,
2215      );
2216  
2217      $term_array = array();
2218  
2219      if ( ! is_array( $excluded_terms ) ) {
2220          if ( ! empty( $excluded_terms ) ) {
2221              $excluded_terms = explode( ',', $excluded_terms );
2222          } else {
2223              $excluded_terms = array();
2224          }
2225      }
2226  
2227      if ( $in_same_term || ! empty( $excluded_terms ) ) {
2228          if ( $in_same_term ) {
2229              $term_array = wp_get_object_terms( $post->ID, $taxonomy, array( 'fields' => 'ids' ) );
2230          }
2231  
2232          if ( ! empty( $excluded_terms ) ) {
2233              $excluded_terms = array_map( 'intval', $excluded_terms );
2234              $excluded_terms = array_diff( $excluded_terms, $term_array );
2235  
2236              $inverse_terms = array();
2237              foreach ( $excluded_terms as $excluded_term ) {
2238                  $inverse_terms[] = $excluded_term * -1;
2239              }
2240              $excluded_terms = $inverse_terms;
2241          }
2242  
2243          $query_args['tax_query'] = array(
2244              array(
2245                  'taxonomy' => $taxonomy,
2246                  'terms'    => array_merge( $term_array, $excluded_terms ),
2247              ),
2248          );
2249      }
2250  
2251      return get_posts( $query_args );
2252  }
2253  
2254  /**
2255   * Retrieves the previous post link that is adjacent to the current post.
2256   *
2257   * @since 3.7.0
2258   *
2259   * @param string       $format         Optional. Link anchor format. Default '&laquo; %link'.
2260   * @param string       $link           Optional. Link permalink format. Default '%title'.
2261   * @param bool         $in_same_term   Optional. Whether link should be in the same taxonomy term.
2262   *                                     Default false.
2263   * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs.
2264   *                                     Default empty.
2265   * @param string       $taxonomy       Optional. Taxonomy, if `$in_same_term` is true. Default 'category'.
2266   * @return string The link URL of the previous post in relation to the current post.
2267   */
2268  function get_previous_post_link( $format = '&laquo; %link', $link = '%title', $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
2269      return get_adjacent_post_link( $format, $link, $in_same_term, $excluded_terms, true, $taxonomy );
2270  }
2271  
2272  /**
2273   * Displays the previous post link that is adjacent to the current post.
2274   *
2275   * @since 1.5.0
2276   *
2277   * @see get_previous_post_link()
2278   *
2279   * @param string       $format         Optional. Link anchor format. Default '&laquo; %link'.
2280   * @param string       $link           Optional. Link permalink format. Default '%title'.
2281   * @param bool         $in_same_term   Optional. Whether link should be in the same taxonomy term.
2282   *                                     Default false.
2283   * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs.
2284   *                                     Default empty.
2285   * @param string       $taxonomy       Optional. Taxonomy, if `$in_same_term` is true. Default 'category'.
2286   */
2287  function previous_post_link( $format = '&laquo; %link', $link = '%title', $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
2288      echo get_previous_post_link( $format, $link, $in_same_term, $excluded_terms, $taxonomy );
2289  }
2290  
2291  /**
2292   * Retrieves the next post link that is adjacent to the current post.
2293   *
2294   * @since 3.7.0
2295   *
2296   * @param string       $format         Optional. Link anchor format. Default '%link &raquo;'.
2297   * @param string       $link           Optional. Link permalink format. Default '%title'.
2298   * @param bool         $in_same_term   Optional. Whether link should be in the same taxonomy term.
2299   *                                     Default false.
2300   * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs.
2301   *                                     Default empty.
2302   * @param string       $taxonomy       Optional. Taxonomy, if `$in_same_term` is true. Default 'category'.
2303   * @return string The link URL of the next post in relation to the current post.
2304   */
2305  function get_next_post_link( $format = '%link &raquo;', $link = '%title', $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
2306      return get_adjacent_post_link( $format, $link, $in_same_term, $excluded_terms, false, $taxonomy );
2307  }
2308  
2309  /**
2310   * Displays the next post link that is adjacent to the current post.
2311   *
2312   * @since 1.5.0
2313   *
2314   * @see get_next_post_link()
2315   *
2316   * @param string       $format         Optional. Link anchor format. Default '%link &raquo;'.
2317   * @param string       $link           Optional. Link permalink format. Default '%title'.
2318   * @param bool         $in_same_term   Optional. Whether link should be in the same taxonomy term.
2319   *                                     Default false.
2320   * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs.
2321   *                                     Default empty.
2322   * @param string       $taxonomy       Optional. Taxonomy, if `$in_same_term` is true. Default 'category'.
2323   */
2324  function next_post_link( $format = '%link &raquo;', $link = '%title', $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
2325      echo get_next_post_link( $format, $link, $in_same_term, $excluded_terms, $taxonomy );
2326  }
2327  
2328  /**
2329   * Retrieves the adjacent post link.
2330   *
2331   * Can be either next post link or previous.
2332   *
2333   * @since 3.7.0
2334   *
2335   * @param string       $format         Link anchor format.
2336   * @param string       $link           Link permalink format.
2337   * @param bool         $in_same_term   Optional. Whether link should be in the same taxonomy term.
2338   *                                     Default false.
2339   * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded terms IDs.
2340   *                                     Default empty.
2341   * @param bool         $previous       Optional. Whether to display link to previous or next post.
2342   *                                     Default true.
2343   * @param string       $taxonomy       Optional. Taxonomy, if `$in_same_term` is true. Default 'category'.
2344   * @return string The link URL of the previous or next post in relation to the current post.
2345   */
2346  function get_adjacent_post_link( $format, $link, $in_same_term = false, $excluded_terms = '', $previous = true, $taxonomy = 'category' ) {
2347      if ( $previous && is_attachment() ) {
2348          $post = get_post( get_post()->post_parent );
2349      } else {
2350          $post = get_adjacent_post( $in_same_term, $excluded_terms, $previous, $taxonomy );
2351      }
2352  
2353      if ( ! $post ) {
2354          $output = '';
2355      } else {
2356          $title = $post->post_title;
2357  
2358          if ( empty( $post->post_title ) ) {
2359              $title = $previous ? __( 'Previous Post' ) : __( 'Next Post' );
2360          }
2361  
2362          /** This filter is documented in wp-includes/post-template.php */
2363          $title = apply_filters( 'the_title', $title, $post->ID );
2364  
2365          $date = mysql2date( get_option( 'date_format' ), $post->post_date );
2366          $rel  = $previous ? 'prev' : 'next';
2367  
2368          $string = '<a href="' . get_permalink( $post ) . '" rel="' . $rel . '">';
2369          $inlink = str_replace( '%title', $title, $link );
2370          $inlink = str_replace( '%date', $date, $inlink );
2371          $inlink = $string . $inlink . '</a>';
2372  
2373          $output = str_replace( '%link', $inlink, $format );
2374      }
2375  
2376      $adjacent = $previous ? 'previous' : 'next';
2377  
2378      /**
2379       * Filters the adjacent post link.
2380       *
2381       * The dynamic portion of the hook name, `$adjacent`, refers to the type
2382       * of adjacency, 'next' or 'previous'.
2383       *
2384       * Possible hook names include:
2385       *
2386       *  - `next_post_link`
2387       *  - `previous_post_link`
2388       *
2389       * @since 2.6.0
2390       * @since 4.2.0 Added the `$adjacent` parameter.
2391       *
2392       * @param string         $output   The adjacent post link.
2393       * @param string         $format   Link anchor format.
2394       * @param string         $link     Link permalink format.
2395       * @param WP_Post|string $post     The adjacent post. Empty string if no corresponding post exists.
2396       * @param string         $adjacent Whether the post is previous or next.
2397       */
2398      return apply_filters( "{$adjacent}_post_link", $output, $format, $link, $post, $adjacent );
2399  }
2400  
2401  /**
2402   * Displays the adjacent post link.
2403   *
2404   * Can be either next post link or previous.
2405   *
2406   * @since 2.5.0
2407   *
2408   * @param string       $format         Link anchor format.
2409   * @param string       $link           Link permalink format.
2410   * @param bool         $in_same_term   Optional. Whether link should be in the same taxonomy term.
2411   *                                     Default false.
2412   * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded category IDs.
2413   *                                     Default empty.
2414   * @param bool         $previous       Optional. Whether to display link to previous or next post.
2415   *                                     Default true.
2416   * @param string       $taxonomy       Optional. Taxonomy, if `$in_same_term` is true. Default 'category'.
2417   */
2418  function adjacent_post_link( $format, $link, $in_same_term = false, $excluded_terms = '', $previous = true, $taxonomy = 'category' ) {
2419      echo get_adjacent_post_link( $format, $link, $in_same_term, $excluded_terms, $previous, $taxonomy );
2420  }
2421  
2422  /**
2423   * Retrieves the link for a page number.
2424   *
2425   * @since 1.5.0
2426   *
2427   * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
2428   *
2429   * @param int  $pagenum Optional. Page number. Default 1.
2430   * @param bool $escape  Optional. Whether to escape the URL for display, with esc_url().
2431   *                      If set to false, prepares the URL with sanitize_url(). Default true.
2432   * @return string The link URL for the given page number.
2433   */
2434  function get_pagenum_link( $pagenum = 1, $escape = true ) {
2435      global $wp_rewrite;
2436  
2437      $pagenum = (int) $pagenum;
2438  
2439      $request = remove_query_arg( 'paged' );
2440  
2441      $home_root = parse_url( home_url() );
2442      $home_root = $home_root['path'] ?? '';
2443      $home_root = preg_quote( $home_root, '|' );
2444  
2445      $request = preg_replace( '|^' . $home_root . '|i', '', $request );
2446      $request = preg_replace( '|^/+|', '', $request );
2447  
2448      if ( ! $wp_rewrite->using_permalinks() || is_admin() ) {
2449          $base = trailingslashit( get_bloginfo( 'url' ) );
2450  
2451          if ( $pagenum > 1 ) {
2452              $result = add_query_arg( 'paged', $pagenum, $base . $request );
2453          } else {
2454              $result = $base . $request;
2455          }
2456      } else {
2457          $qs_regex = '|\?.*?$|';
2458          preg_match( $qs_regex, $request, $qs_match );
2459  
2460          $parts   = array();
2461          $parts[] = untrailingslashit( get_bloginfo( 'url' ) );
2462  
2463          if ( ! empty( $qs_match[0] ) ) {
2464              $query_string = $qs_match[0];
2465              $request      = preg_replace( $qs_regex, '', $request );
2466          } else {
2467              $query_string = '';
2468          }
2469  
2470          $request = preg_replace( "|$wp_rewrite->pagination_base/\d+/?$|", '', $request );
2471          $request = preg_replace( '|^' . preg_quote( $wp_rewrite->index, '|' ) . '|i', '', $request );
2472          $request = ltrim( $request, '/' );
2473  
2474          if ( $wp_rewrite->using_index_permalinks() && ( $pagenum > 1 || '' !== $request ) ) {
2475              $parts[] = $wp_rewrite->index;
2476          }
2477  
2478          $parts[] = untrailingslashit( $request );
2479  
2480          if ( $pagenum > 1 ) {
2481              $parts[] = $wp_rewrite->pagination_base;
2482              $parts[] = $pagenum;
2483          }
2484  
2485          $result = user_trailingslashit( implode( '/', array_filter( $parts ) ), 'paged' );
2486          if ( ! empty( $query_string ) ) {
2487              $result .= $query_string;
2488          }
2489      }
2490  
2491      /**
2492       * Filters the page number link for the current request.
2493       *
2494       * @since 2.5.0
2495       * @since 5.2.0 Added the `$pagenum` argument.
2496       *
2497       * @param string $result  The page number link.
2498       * @param int    $pagenum The page number.
2499       */
2500      $result = apply_filters( 'get_pagenum_link', $result, $pagenum );
2501  
2502      if ( $escape ) {
2503          return esc_url( $result );
2504      } else {
2505          return sanitize_url( $result );
2506      }
2507  }
2508  
2509  /**
2510   * Retrieves the next posts page link.
2511   *
2512   * Backported from 2.1.3 to 2.0.10.
2513   *
2514   * @since 2.0.10
2515   *
2516   * @global int $paged
2517   *
2518   * @param int $max_page Optional. Max pages. Default 0.
2519   * @return string|null The link URL for next posts page.
2520   */
2521  function get_next_posts_page_link( $max_page = 0 ) {
2522      global $paged;
2523  
2524      if ( ! is_single() ) {
2525          if ( ! $paged ) {
2526              $paged = 1;
2527          }
2528  
2529          $next_page = (int) $paged + 1;
2530  
2531          if ( ! $max_page || $max_page >= $next_page ) {
2532              return get_pagenum_link( $next_page );
2533          }
2534      }
2535  
2536      return null;
2537  }
2538  
2539  /**
2540   * Displays or retrieves the next posts page link.
2541   *
2542   * @since 0.71
2543   *
2544   * @param int  $max_page Optional. Max pages. Default 0.
2545   * @param bool $display  Optional. Whether to echo the link. Default true.
2546   * @return string|null The link URL for next posts page if `$display = false`.
2547   */
2548  function next_posts( $max_page = 0, $display = true ) {
2549      $link   = get_next_posts_page_link( $max_page );
2550      $output = $link ? esc_url( $link ) : '';
2551  
2552      if ( ! $display ) {
2553          return $output;
2554      }
2555  
2556      echo $output;
2557  
2558      return null;
2559  }
2560  
2561  /**
2562   * Retrieves the next posts page link.
2563   *
2564   * @since 2.7.0
2565   *
2566   * @global int      $paged
2567   * @global WP_Query $wp_query WordPress Query object.
2568   *
2569   * @param string $label    Content for link text.
2570   * @param int    $max_page Optional. Max pages. Default 0.
2571   * @return string|null HTML-formatted next posts page link.
2572   */
2573  function get_next_posts_link( $label = null, $max_page = 0 ) {
2574      global $paged, $wp_query;
2575  
2576      if ( ! $max_page ) {
2577          $max_page = $wp_query->max_num_pages;
2578      }
2579  
2580      if ( ! $paged ) {
2581          $paged = 1;
2582      }
2583  
2584      $next_page = (int) $paged + 1;
2585  
2586      if ( null === $label ) {
2587          $label = __( 'Next Page &raquo;' );
2588      }
2589  
2590      if ( ! is_single() && ( $next_page <= $max_page ) ) {
2591          /**
2592           * Filters the anchor tag attributes for the next posts page link.
2593           *
2594           * @since 2.7.0
2595           *
2596           * @param string $attributes Attributes for the anchor tag.
2597           */
2598          $attr = apply_filters( 'next_posts_link_attributes', '' );
2599  
2600          return sprintf(
2601              '<a href="%1$s" %2$s>%3$s</a>',
2602              next_posts( $max_page, false ),
2603              $attr,
2604              preg_replace( '/&([^#])(?![a-z]{1,8};)/i', '&#038;$1', $label )
2605          );
2606      }
2607  
2608      return null;
2609  }
2610  
2611  /**
2612   * Displays the next posts page link.
2613   *
2614   * @since 0.71
2615   *
2616   * @param string $label    Content for link text.
2617   * @param int    $max_page Optional. Max pages. Default 0.
2618   */
2619  function next_posts_link( $label = null, $max_page = 0 ) {
2620      echo get_next_posts_link( $label, $max_page );
2621  }
2622  
2623  /**
2624   * Retrieves the previous posts page link.
2625   *
2626   * Will only return string, if not on a single page or post.
2627   *
2628   * Backported to 2.0.10 from 2.1.3.
2629   *
2630   * @since 2.0.10
2631   *
2632   * @global int $paged
2633   *
2634   * @return string|null The link for the previous posts page.
2635   */
2636  function get_previous_posts_page_link() {
2637      global $paged;
2638  
2639      if ( ! is_single() ) {
2640          $previous_page = (int) $paged - 1;
2641  
2642          if ( $previous_page < 1 ) {
2643              $previous_page = 1;
2644          }
2645  
2646          return get_pagenum_link( $previous_page );
2647      }
2648  
2649      return null;
2650  }
2651  
2652  /**
2653   * Displays or retrieves the previous posts page link.
2654   *
2655   * @since 0.71
2656   *
2657   * @param bool $display Optional. Whether to echo the link. Default true.
2658   * @return string|null The previous posts page link if `$display = false`.
2659   */
2660  function previous_posts( $display = true ) {
2661      $link   = get_previous_posts_page_link();
2662      $output = $link ? esc_url( $link ) : '';
2663  
2664      if ( ! $display ) {
2665          return $output;
2666      }
2667  
2668      echo $output;
2669  
2670      return null;
2671  }
2672  
2673  /**
2674   * Retrieves the previous posts page link.
2675   *
2676   * @since 2.7.0
2677   *
2678   * @global int $paged
2679   *
2680   * @param string $label Optional. Previous page link text.
2681   * @return string|null HTML-formatted previous page link.
2682   */
2683  function get_previous_posts_link( $label = null ) {
2684      global $paged;
2685  
2686      if ( null === $label ) {
2687          $label = __( '&laquo; Previous Page' );
2688      }
2689  
2690      if ( ! is_single() && $paged > 1 ) {
2691          /**
2692           * Filters the anchor tag attributes for the previous posts page link.
2693           *
2694           * @since 2.7.0
2695           *
2696           * @param string $attributes Attributes for the anchor tag.
2697           */
2698          $attr = apply_filters( 'previous_posts_link_attributes', '' );
2699  
2700          return sprintf(
2701              '<a href="%1$s" %2$s>%3$s</a>',
2702              previous_posts( false ),
2703              $attr,
2704              preg_replace( '/&([^#])(?![a-z]{1,8};)/i', '&#038;$1', $label )
2705          );
2706      }
2707  
2708      return null;
2709  }
2710  
2711  /**
2712   * Displays the previous posts page link.
2713   *
2714   * @since 0.71
2715   *
2716   * @param string $label Optional. Previous page link text.
2717   */
2718  function previous_posts_link( $label = null ) {
2719      echo get_previous_posts_link( $label );
2720  }
2721  
2722  /**
2723   * Retrieves the post pages link navigation for previous and next pages.
2724   *
2725   * @since 2.8.0
2726   *
2727   * @global WP_Query $wp_query WordPress Query object.
2728   *
2729   * @param string|array $args {
2730   *     Optional. Arguments to build the post pages link navigation.
2731   *
2732   *     @type string $sep      Separator character. Default '&#8212;'.
2733   *     @type string $prelabel Link text to display for the previous page link.
2734   *                            Default '&laquo; Previous Page'.
2735   *     @type string $nxtlabel Link text to display for the next page link.
2736   *                            Default 'Next Page &raquo;'.
2737   * }
2738   * @return string The posts link navigation.
2739   */
2740  function get_posts_nav_link( $args = array() ) {
2741      global $wp_query;
2742  
2743      $return = '';
2744  
2745      if ( ! is_singular() ) {
2746          $defaults = array(
2747              'sep'      => ' &#8212; ',
2748              'prelabel' => __( '&laquo; Previous Page' ),
2749              'nxtlabel' => __( 'Next Page &raquo;' ),
2750          );
2751          $args     = wp_parse_args( $args, $defaults );
2752  
2753          $max_num_pages = $wp_query->max_num_pages;
2754          $paged         = get_query_var( 'paged' );
2755  
2756          // Only have sep if there's both prev and next results.
2757          if ( $paged < 2 || $paged >= $max_num_pages ) {
2758              $args['sep'] = '';
2759          }
2760  
2761          if ( $max_num_pages > 1 ) {
2762              $return  = get_previous_posts_link( $args['prelabel'] );
2763              $return .= preg_replace( '/&([^#])(?![a-z]{1,8};)/i', '&#038;$1', $args['sep'] );
2764              $return .= get_next_posts_link( $args['nxtlabel'] );
2765          }
2766      }
2767      return $return;
2768  }
2769  
2770  /**
2771   * Displays the post pages link navigation for previous and next pages.
2772   *
2773   * @since 0.71
2774   *
2775   * @param string $sep      Optional. Separator for posts navigation links. Default empty.
2776   * @param string $prelabel Optional. Label for previous pages. Default empty.
2777   * @param string $nxtlabel Optional Label for next pages. Default empty.
2778   */
2779  function posts_nav_link( $sep = '', $prelabel = '', $nxtlabel = '' ) {
2780      $args = array_filter( compact( 'sep', 'prelabel', 'nxtlabel' ) );
2781      echo get_posts_nav_link( $args );
2782  }
2783  
2784  /**
2785   * Retrieves the navigation to next/previous post, when applicable.
2786   *
2787   * @since 4.1.0
2788   * @since 4.4.0 Introduced the `in_same_term`, `excluded_terms`, and `taxonomy` arguments.
2789   * @since 5.3.0 Added the `aria_label` parameter.
2790   * @since 5.5.0 Added the `class` parameter.
2791   *
2792   * @param array $args {
2793   *     Optional. Default post navigation arguments. Default empty array.
2794   *
2795   *     @type string       $prev_text          Anchor text to display in the previous post link.
2796   *                                            Default '%title'.
2797   *     @type string       $next_text          Anchor text to display in the next post link.
2798   *                                            Default '%title'.
2799   *     @type bool         $in_same_term       Whether link should be in the same taxonomy term.
2800   *                                            Default false.
2801   *     @type int[]|string $excluded_terms     Array or comma-separated list of excluded term IDs.
2802   *                                            Default empty.
2803   *     @type string       $taxonomy           Taxonomy, if `$in_same_term` is true. Default 'category'.
2804   *     @type string       $screen_reader_text Screen reader text for the nav element.
2805   *                                            Default 'Post navigation'.
2806   *     @type string       $aria_label         ARIA label text for the nav element. Default 'Posts'.
2807   *     @type string       $class              Custom class for the nav element. Default 'post-navigation'.
2808   * }
2809   * @return string Markup for post links.
2810   */
2811  function get_the_post_navigation( $args = array() ) {
2812      // Make sure the nav element has an aria-label attribute: fallback to the screen reader text.
2813      if ( ! empty( $args['screen_reader_text'] ) && empty( $args['aria_label'] ) ) {
2814          $args['aria_label'] = $args['screen_reader_text'];
2815      }
2816  
2817      $args = wp_parse_args(
2818          $args,
2819          array(
2820              'prev_text'          => '%title',
2821              'next_text'          => '%title',
2822              'in_same_term'       => false,
2823              'excluded_terms'     => '',
2824              'taxonomy'           => 'category',
2825              'screen_reader_text' => __( 'Post navigation' ),
2826              'aria_label'         => __( 'Posts' ),
2827              'class'              => 'post-navigation',
2828          )
2829      );
2830  
2831      $navigation = '';
2832  
2833      $previous = get_previous_post_link(
2834          '<div class="nav-previous">%link</div>',
2835          $args['prev_text'],
2836          $args['in_same_term'],
2837          $args['excluded_terms'],
2838          $args['taxonomy']
2839      );
2840  
2841      $next = get_next_post_link(
2842          '<div class="nav-next">%link</div>',
2843          $args['next_text'],
2844          $args['in_same_term'],
2845          $args['excluded_terms'],
2846          $args['taxonomy']
2847      );
2848  
2849      // Only add markup if there's somewhere to navigate to.
2850      if ( $previous || $next ) {
2851          $navigation = _navigation_markup( $previous . $next, $args['class'], $args['screen_reader_text'], $args['aria_label'] );
2852      }
2853  
2854      return $navigation;
2855  }
2856  
2857  /**
2858   * Displays the navigation to next/previous post, when applicable.
2859   *
2860   * @since 4.1.0
2861   *
2862   * @param array $args Optional. See get_the_post_navigation() for available arguments.
2863   *                    Default empty array.
2864   */
2865  function the_post_navigation( $args = array() ) {
2866      echo get_the_post_navigation( $args );
2867  }
2868  
2869  /**
2870   * Returns the navigation to next/previous set of posts, when applicable.
2871   *
2872   * @since 4.1.0
2873   * @since 5.3.0 Added the `aria_label` parameter.
2874   * @since 5.5.0 Added the `class` parameter.
2875   *
2876   * @global WP_Query $wp_query WordPress Query object.
2877   *
2878   * @param array $args {
2879   *     Optional. Default posts navigation arguments. Default empty array.
2880   *
2881   *     @type string $prev_text          Anchor text to display in the previous posts link.
2882   *                                      Default 'Older posts'.
2883   *     @type string $next_text          Anchor text to display in the next posts link.
2884   *                                      Default 'Newer posts'.
2885   *     @type string $screen_reader_text Screen reader text for the nav element.
2886   *                                      Default 'Posts navigation'.
2887   *     @type string $aria_label         ARIA label text for the nav element. Default 'Posts'.
2888   *     @type string $class              Custom class for the nav element. Default 'posts-navigation'.
2889   * }
2890   * @return string Markup for posts links.
2891   */
2892  function get_the_posts_navigation( $args = array() ) {
2893      global $wp_query;
2894  
2895      $navigation = '';
2896  
2897      // Don't print empty markup if there's only one page.
2898      if ( $wp_query->max_num_pages > 1 ) {
2899          // Make sure the nav element has an aria-label attribute: fallback to the screen reader text.
2900          if ( ! empty( $args['screen_reader_text'] ) && empty( $args['aria_label'] ) ) {
2901              $args['aria_label'] = $args['screen_reader_text'];
2902          }
2903  
2904          $args = wp_parse_args(
2905              $args,
2906              array(
2907                  'prev_text'          => __( 'Older posts' ),
2908                  'next_text'          => __( 'Newer posts' ),
2909                  'screen_reader_text' => __( 'Posts navigation' ),
2910                  'aria_label'         => __( 'Posts' ),
2911                  'class'              => 'posts-navigation',
2912              )
2913          );
2914  
2915          $next_link = get_previous_posts_link( $args['next_text'] );
2916          $prev_link = get_next_posts_link( $args['prev_text'] );
2917  
2918          if ( $prev_link ) {
2919              $navigation .= '<div class="nav-previous">' . $prev_link . '</div>';
2920          }
2921  
2922          if ( $next_link ) {
2923              $navigation .= '<div class="nav-next">' . $next_link . '</div>';
2924          }
2925  
2926          $navigation = _navigation_markup( $navigation, $args['class'], $args['screen_reader_text'], $args['aria_label'] );
2927      }
2928  
2929      return $navigation;
2930  }
2931  
2932  /**
2933   * Displays the navigation to next/previous set of posts, when applicable.
2934   *
2935   * @since 4.1.0
2936   *
2937   * @param array $args Optional. See get_the_posts_navigation() for available arguments.
2938   *                    Default empty array.
2939   */
2940  function the_posts_navigation( $args = array() ) {
2941      echo get_the_posts_navigation( $args );
2942  }
2943  
2944  /**
2945   * Retrieves a paginated navigation to next/previous set of posts, when applicable.
2946   *
2947   * @since 4.1.0
2948   * @since 5.3.0 Added the `aria_label` parameter.
2949   * @since 5.5.0 Added the `class` parameter.
2950   *
2951   * @global WP_Query $wp_query WordPress Query object.
2952   *
2953   * @param array $args {
2954   *     Optional. Default pagination arguments, see paginate_links().
2955   *
2956   *     @type string $screen_reader_text Screen reader text for navigation element.
2957   *                                      Default 'Posts pagination'.
2958   *     @type string $aria_label         ARIA label text for the nav element. Default 'Posts pagination'.
2959   *     @type string $class              Custom class for the nav element. Default 'pagination'.
2960   * }
2961   * @return string Markup for pagination links.
2962   */
2963  function get_the_posts_pagination( $args = array() ) {
2964      global $wp_query;
2965  
2966      $navigation = '';
2967  
2968      // Don't print empty markup if there's only one page.
2969      if ( $wp_query->max_num_pages > 1 ) {
2970          // Make sure the nav element has an aria-label attribute: fallback to the screen reader text.
2971          if ( ! empty( $args['screen_reader_text'] ) && empty( $args['aria_label'] ) ) {
2972              $args['aria_label'] = $args['screen_reader_text'];
2973          }
2974  
2975          $args = wp_parse_args(
2976              $args,
2977              array(
2978                  'mid_size'           => 1,
2979                  'prev_text'          => _x( 'Previous', 'previous set of posts' ),
2980                  'next_text'          => _x( 'Next', 'next set of posts' ),
2981                  'screen_reader_text' => __( 'Posts pagination' ),
2982                  'aria_label'         => __( 'Posts pagination' ),
2983                  'class'              => 'pagination',
2984              )
2985          );
2986  
2987          /**
2988           * Filters the arguments for posts pagination links.
2989           *
2990           * @since 6.1.0
2991           *
2992           * @param array $args {
2993           *     Optional. Default pagination arguments, see paginate_links().
2994           *
2995           *     @type string $screen_reader_text Screen reader text for navigation element.
2996           *                                      Default 'Posts navigation'.
2997           *     @type string $aria_label         ARIA label text for the nav element. Default 'Posts'.
2998           *     @type string $class              Custom class for the nav element. Default 'pagination'.
2999           * }
3000           */
3001          $args = apply_filters( 'the_posts_pagination_args', $args );
3002  
3003          // Make sure we get a string back. Plain is the next best thing.
3004          if ( isset( $args['type'] ) && 'array' === $args['type'] ) {
3005              $args['type'] = 'plain';
3006          }
3007  
3008          // Set up paginated links.
3009          $links = paginate_links( $args );
3010  
3011          if ( $links ) {
3012              $navigation = _navigation_markup( $links, $args['class'], $args['screen_reader_text'], $args['aria_label'] );
3013          }
3014      }
3015  
3016      return $navigation;
3017  }
3018  
3019  /**
3020   * Displays a paginated navigation to next/previous set of posts, when applicable.
3021   *
3022   * @since 4.1.0
3023   *
3024   * @param array $args Optional. See get_the_posts_pagination() for available arguments.
3025   *                    Default empty array.
3026   */
3027  function the_posts_pagination( $args = array() ) {
3028      echo get_the_posts_pagination( $args );
3029  }
3030  
3031  /**
3032   * Wraps passed links in navigational markup.
3033   *
3034   * @since 4.1.0
3035   * @since 5.3.0 Added the `aria_label` parameter.
3036   * @access private
3037   *
3038   * @param string $links              Navigational links.
3039   * @param string $css_class          Optional. Custom class for the nav element.
3040   *                                   Default 'posts-navigation'.
3041   * @param string $screen_reader_text Optional. Screen reader text for the nav element.
3042   *                                   Default 'Posts navigation'.
3043   * @param string $aria_label         Optional. ARIA label for the nav element.
3044   *                                   Defaults to the value of `$screen_reader_text`.
3045   * @return string Navigation template tag.
3046   */
3047  function _navigation_markup( $links, $css_class = 'posts-navigation', $screen_reader_text = '', $aria_label = '' ) {
3048      if ( empty( $screen_reader_text ) ) {
3049          $screen_reader_text = /* translators: Hidden accessibility text. */ __( 'Posts navigation' );
3050      }
3051      if ( empty( $aria_label ) ) {
3052          $aria_label = $screen_reader_text;
3053      }
3054  
3055      $template = '
3056      <nav class="navigation %1$s" aria-label="%4$s">
3057          <h2 class="screen-reader-text">%2$s</h2>
3058          <div class="nav-links">%3$s</div>
3059      </nav>';
3060  
3061      /**
3062       * Filters the navigation markup template.
3063       *
3064       * Note: The filtered template HTML must contain specifiers for the navigation
3065       * class (%1$s), the screen-reader-text value (%2$s), placement of the navigation
3066       * links (%3$s), and ARIA label text if screen-reader-text does not fit that (%4$s):
3067       *
3068       *     <nav class="navigation %1$s" aria-label="%4$s">
3069       *         <h2 class="screen-reader-text">%2$s</h2>
3070       *         <div class="nav-links">%3$s</div>
3071       *     </nav>
3072       *
3073       * @since 4.4.0
3074       *
3075       * @param string $template  The default template.
3076       * @param string $css_class The class passed by the calling function.
3077       */
3078      $template = apply_filters( 'navigation_markup_template', $template, $css_class );
3079  
3080      return sprintf( $template, sanitize_html_class( $css_class ), esc_html( $screen_reader_text ), $links, esc_attr( $aria_label ) );
3081  }
3082  
3083  /**
3084   * Retrieves the comments page number link.
3085   *
3086   * @since 2.7.0
3087   *
3088   * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
3089   *
3090   * @param int $pagenum  Optional. Page number. Default 1.
3091   * @param int $max_page Optional. The maximum number of comment pages. Default 0.
3092   * @return string The comments page number link URL.
3093   */
3094  function get_comments_pagenum_link( $pagenum = 1, $max_page = 0 ) {
3095      global $wp_rewrite;
3096  
3097      $pagenum  = (int) $pagenum;
3098      $max_page = (int) $max_page;
3099  
3100      $result = get_permalink();
3101  
3102      if ( 'newest' === get_option( 'default_comments_page' ) ) {
3103          if ( $pagenum !== $max_page ) {
3104              if ( $wp_rewrite->using_permalinks() ) {
3105                  $result = user_trailingslashit( trailingslashit( $result ) . $wp_rewrite->comments_pagination_base . '-' . $pagenum, 'commentpaged' );
3106              } else {
3107                  $result = add_query_arg( 'cpage', $pagenum, $result );
3108              }
3109          }
3110      } elseif ( $pagenum > 1 ) {
3111          if ( $wp_rewrite->using_permalinks() ) {
3112              $result = user_trailingslashit( trailingslashit( $result ) . $wp_rewrite->comments_pagination_base . '-' . $pagenum, 'commentpaged' );
3113          } else {
3114              $result = add_query_arg( 'cpage', $pagenum, $result );
3115          }
3116      }
3117  
3118      $result .= '#comments';
3119  
3120      /**
3121       * Filters the comments page number link for the current request.
3122       *
3123       * @since 2.7.0
3124       *
3125       * @param string $result The comments page number link.
3126       */
3127      return apply_filters( 'get_comments_pagenum_link', $result );
3128  }
3129  
3130  /**
3131   * Retrieves the link to the next comments page.
3132   *
3133   * @since 2.7.1
3134   * @since 6.7.0 Added the `page` parameter.
3135   *
3136   * @global WP_Query $wp_query WordPress Query object.
3137   *
3138   * @param string   $label    Optional. Label for link text. Default empty.
3139   * @param int      $max_page Optional. Max page. Default 0.
3140   * @param int|null $page     Optional. Page number. Default null.
3141   * @return string|null HTML-formatted link for the next page of comments.
3142   */
3143  function get_next_comments_link( $label = '', $max_page = 0, $page = null ) {
3144      global $wp_query;
3145  
3146      if ( ! is_singular() ) {
3147          return null;
3148      }
3149  
3150      if ( is_null( $page ) ) {
3151          $page = get_query_var( 'cpage' );
3152      }
3153  
3154      if ( ! $page ) {
3155          $page = 1;
3156      }
3157  
3158      $next_page = (int) $page + 1;
3159  
3160      if ( empty( $max_page ) ) {
3161          $max_page = $wp_query->max_num_comment_pages;
3162      }
3163  
3164      if ( empty( $max_page ) ) {
3165          $max_page = get_comment_pages_count();
3166      }
3167  
3168      if ( $next_page > $max_page ) {
3169          return null;
3170      }
3171  
3172      if ( empty( $label ) ) {
3173          $label = __( 'Newer Comments &raquo;' );
3174      }
3175  
3176      /**
3177       * Filters the anchor tag attributes for the next comments page link.
3178       *
3179       * @since 2.7.0
3180       *
3181       * @param string $attributes Attributes for the anchor tag.
3182       */
3183      $attr = apply_filters( 'next_comments_link_attributes', '' );
3184  
3185      return sprintf(
3186          '<a href="%1$s" %2$s>%3$s</a>',
3187          esc_url( get_comments_pagenum_link( $next_page, $max_page ) ),
3188          $attr,
3189          preg_replace( '/&([^#])(?![a-z]{1,8};)/i', '&#038;$1', $label )
3190      );
3191  }
3192  
3193  /**
3194   * Displays the link to the next comments page.
3195   *
3196   * @since 2.7.0
3197   *
3198   * @param string $label    Optional. Label for link text. Default empty.
3199   * @param int    $max_page Optional. Max page. Default 0.
3200   */
3201  function next_comments_link( $label = '', $max_page = 0 ) {
3202      echo get_next_comments_link( $label, $max_page );
3203  }
3204  
3205  /**
3206   * Retrieves the link to the previous comments page.
3207   *
3208   * @since 2.7.1
3209   * @since 6.7.0 Added the `page` parameter.
3210   *
3211   * @param string   $label Optional. Label for comments link text. Default empty.
3212   * @param int|null $page  Optional. Page number. Default null.
3213   * @return string|null HTML-formatted link for the previous page of comments.
3214   */
3215  function get_previous_comments_link( $label = '', $page = null ) {
3216      if ( ! is_singular() ) {
3217          return null;
3218      }
3219  
3220      if ( is_null( $page ) ) {
3221          $page = get_query_var( 'cpage' );
3222      }
3223  
3224      if ( (int) $page <= 1 ) {
3225          return null;
3226      }
3227  
3228      $previous_page = (int) $page - 1;
3229  
3230      if ( empty( $label ) ) {
3231          $label = __( '&laquo; Older Comments' );
3232      }
3233  
3234      /**
3235       * Filters the anchor tag attributes for the previous comments page link.
3236       *
3237       * @since 2.7.0
3238       *
3239       * @param string $attributes Attributes for the anchor tag.
3240       */
3241      $attr = apply_filters( 'previous_comments_link_attributes', '' );
3242  
3243      return sprintf(
3244          '<a href="%1$s" %2$s>%3$s</a>',
3245          esc_url( get_comments_pagenum_link( $previous_page ) ),
3246          $attr,
3247          preg_replace( '/&([^#])(?![a-z]{1,8};)/i', '&#038;$1', $label )
3248      );
3249  }
3250  
3251  /**
3252   * Displays the link to the previous comments page.
3253   *
3254   * @since 2.7.0
3255   *
3256   * @param string $label Optional. Label for comments link text. Default empty.
3257   */
3258  function previous_comments_link( $label = '' ) {
3259      echo get_previous_comments_link( $label );
3260  }
3261  
3262  /**
3263   * Displays or retrieves pagination links for the comments on the current post.
3264   *
3265   * @see paginate_links()
3266   * @since 2.7.0
3267   *
3268   * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
3269   *
3270   * @param string|array $args Optional args. See paginate_links(). Default empty array.
3271   * @return void|string|array Void if 'echo' argument is true and 'type' is not an array,
3272   *                           or if the query is not for an existing single post of any post type.
3273   *                           Otherwise, markup for comment page links or array of comment page links,
3274   *                           depending on 'type' argument.
3275   */
3276  function paginate_comments_links( $args = array() ) {
3277      global $wp_rewrite;
3278  
3279      if ( ! is_singular() ) {
3280          return;
3281      }
3282  
3283      $page = get_query_var( 'cpage' );
3284      if ( ! $page ) {
3285          $page = 1;
3286      }
3287      $max_page = get_comment_pages_count();
3288      $defaults = array(
3289          'base'         => add_query_arg( 'cpage', '%#%' ),
3290          'format'       => '',
3291          'total'        => $max_page,
3292          'current'      => $page,
3293          'echo'         => true,
3294          'type'         => 'plain',
3295          'add_fragment' => '#comments',
3296      );
3297      if ( $wp_rewrite->using_permalinks() ) {
3298          $defaults['base'] = user_trailingslashit( trailingslashit( get_permalink() ) . $wp_rewrite->comments_pagination_base . '-%#%', 'commentpaged' );
3299      }
3300  
3301      $args       = wp_parse_args( $args, $defaults );
3302      $page_links = paginate_links( $args );
3303  
3304      if ( $args['echo'] && 'array' !== $args['type'] ) {
3305          echo $page_links;
3306      } else {
3307          return $page_links;
3308      }
3309  }
3310  
3311  /**
3312   * Retrieves navigation to next/previous set of comments, when applicable.
3313   *
3314   * @since 4.4.0
3315   * @since 5.3.0 Added the `aria_label` parameter.
3316   * @since 5.5.0 Added the `class` parameter.
3317   *
3318   * @param array $args {
3319   *     Optional. Default comments navigation arguments.
3320   *
3321   *     @type string $prev_text          Anchor text to display in the previous comments link.
3322   *                                      Default 'Older comments'.
3323   *     @type string $next_text          Anchor text to display in the next comments link.
3324   *                                      Default 'Newer comments'.
3325   *     @type string $screen_reader_text Screen reader text for the nav element. Default 'Comments navigation'.
3326   *     @type string $aria_label         ARIA label text for the nav element. Default 'Comments'.
3327   *     @type string $class              Custom class for the nav element. Default 'comment-navigation'.
3328   * }
3329   * @return string Markup for comments links.
3330   */
3331  function get_the_comments_navigation( $args = array() ) {
3332      $navigation = '';
3333  
3334      // Are there comments to navigate through?
3335      if ( get_comment_pages_count() > 1 ) {
3336          // Make sure the nav element has an aria-label attribute: fallback to the screen reader text.
3337          if ( ! empty( $args['screen_reader_text'] ) && empty( $args['aria_label'] ) ) {
3338              $args['aria_label'] = $args['screen_reader_text'];
3339          }
3340  
3341          $args = wp_parse_args(
3342              $args,
3343              array(
3344                  'prev_text'          => __( 'Older comments' ),
3345                  'next_text'          => __( 'Newer comments' ),
3346                  'screen_reader_text' => __( 'Comments navigation' ),
3347                  'aria_label'         => __( 'Comments' ),
3348                  'class'              => 'comment-navigation',
3349              )
3350          );
3351  
3352          $prev_link = get_previous_comments_link( $args['prev_text'] );
3353          $next_link = get_next_comments_link( $args['next_text'] );
3354  
3355          if ( $prev_link ) {
3356              $navigation .= '<div class="nav-previous">' . $prev_link . '</div>';
3357          }
3358  
3359          if ( $next_link ) {
3360              $navigation .= '<div class="nav-next">' . $next_link . '</div>';
3361          }
3362  
3363          $navigation = _navigation_markup( $navigation, $args['class'], $args['screen_reader_text'], $args['aria_label'] );
3364      }
3365  
3366      return $navigation;
3367  }
3368  
3369  /**
3370   * Displays navigation to next/previous set of comments, when applicable.
3371   *
3372   * @since 4.4.0
3373   *
3374   * @param array $args See get_the_comments_navigation() for available arguments. Default empty array.
3375   */
3376  function the_comments_navigation( $args = array() ) {
3377      echo get_the_comments_navigation( $args );
3378  }
3379  
3380  /**
3381   * Retrieves a paginated navigation to next/previous set of comments, when applicable.
3382   *
3383   * @since 4.4.0
3384   * @since 5.3.0 Added the `aria_label` parameter.
3385   * @since 5.5.0 Added the `class` parameter.
3386   *
3387   * @see paginate_comments_links()
3388   *
3389   * @param array $args {
3390   *     Optional. Default pagination arguments.
3391   *
3392   *     @type string $screen_reader_text Screen reader text for the nav element. Default 'Comments pagination'.
3393   *     @type string $aria_label         ARIA label text for the nav element. Default 'Comments pagination'.
3394   *     @type string $class              Custom class for the nav element. Default 'comments-pagination'.
3395   * }
3396   * @return string Markup for pagination links.
3397   */
3398  function get_the_comments_pagination( $args = array() ) {
3399      $navigation = '';
3400  
3401      // Make sure the nav element has an aria-label attribute: fallback to the screen reader text.
3402      if ( ! empty( $args['screen_reader_text'] ) && empty( $args['aria_label'] ) ) {
3403          $args['aria_label'] = $args['screen_reader_text'];
3404      }
3405  
3406      $args         = wp_parse_args(
3407          $args,
3408          array(
3409              'screen_reader_text' => __( 'Comments pagination' ),
3410              'aria_label'         => __( 'Comments pagination' ),
3411              'class'              => 'comments-pagination',
3412          )
3413      );
3414      $args['echo'] = false;
3415  
3416      // Make sure we get a string back. Plain is the next best thing.
3417      if ( isset( $args['type'] ) && 'array' === $args['type'] ) {
3418          $args['type'] = 'plain';
3419      }
3420  
3421      $links = paginate_comments_links( $args );
3422  
3423      if ( $links ) {
3424          $navigation = _navigation_markup( $links, $args['class'], $args['screen_reader_text'], $args['aria_label'] );
3425      }
3426  
3427      return $navigation;
3428  }
3429  
3430  /**
3431   * Displays a paginated navigation to next/previous set of comments, when applicable.
3432   *
3433   * @since 4.4.0
3434   *
3435   * @param array $args See get_the_comments_pagination() for available arguments. Default empty array.
3436   */
3437  function the_comments_pagination( $args = array() ) {
3438      echo get_the_comments_pagination( $args );
3439  }
3440  
3441  /**
3442   * Retrieves the URL for the current site where the front end is accessible.
3443   *
3444   * Returns the 'home' option with the appropriate protocol. The protocol will be 'https'
3445   * if is_ssl() evaluates to true; otherwise, it will be the same as the 'home' option.
3446   * If `$scheme` is 'http' or 'https', is_ssl() is overridden.
3447   *
3448   * @since 3.0.0
3449   *
3450   * @param string      $path   Optional. Path relative to the home URL. Default empty.
3451   * @param string|null $scheme Optional. Scheme to give the home URL context. Accepts
3452   *                            'http', 'https', 'relative', 'rest', or null. Default null.
3453   * @return string Home URL link with optional path appended.
3454   */
3455  function home_url( $path = '', $scheme = null ) {
3456      return get_home_url( null, $path, $scheme );
3457  }
3458  
3459  /**
3460   * Retrieves the URL for a given site where the front end is accessible.
3461   *
3462   * Returns the 'home' option with the appropriate protocol. The protocol will be 'https'
3463   * if is_ssl() evaluates to true; otherwise, it will be the same as the 'home' option.
3464   * If `$scheme` is 'http' or 'https', is_ssl() is overridden.
3465   *
3466   * @since 3.0.0
3467   *
3468   * @param int|null    $blog_id Optional. Site ID. Default null (current site).
3469   * @param string      $path    Optional. Path relative to the home URL. Default empty.
3470   * @param string|null $scheme  Optional. Scheme to give the home URL context. Accepts
3471   *                             'http', 'https', 'relative', 'rest', or null. Default null.
3472   * @return string Home URL link with optional path appended.
3473   */
3474  function get_home_url( $blog_id = null, $path = '', $scheme = null ) {
3475      $orig_scheme = $scheme;
3476  
3477      if ( empty( $blog_id ) || ! is_multisite() ) {
3478          $url = get_option( 'home' );
3479      } else {
3480          switch_to_blog( $blog_id );
3481          $url = get_option( 'home' );
3482          restore_current_blog();
3483      }
3484  
3485      if ( ! in_array( $scheme, array( 'http', 'https', 'relative' ), true ) ) {
3486          if ( is_ssl() ) {
3487              $scheme = 'https';
3488          } else {
3489              $scheme = parse_url( $url, PHP_URL_SCHEME );
3490          }
3491      }
3492  
3493      $url = set_url_scheme( $url, $scheme );
3494  
3495      if ( $path && is_string( $path ) ) {
3496          $url .= '/' . ltrim( $path, '/' );
3497      }
3498  
3499      /**
3500       * Filters the home URL.
3501       *
3502       * @since 3.0.0
3503       *
3504       * @param string      $url         The complete home URL including scheme and path.
3505       * @param string      $path        Path relative to the home URL. Blank string if no path is specified.
3506       * @param string|null $orig_scheme Scheme to give the home URL context. Accepts 'http', 'https',
3507       *                                 'relative', 'rest', or null.
3508       * @param int|null    $blog_id     Site ID, or null for the current site.
3509       */
3510      return apply_filters( 'home_url', $url, $path, $orig_scheme, $blog_id );
3511  }
3512  
3513  /**
3514   * Retrieves the URL for the current site where WordPress application files
3515   * (e.g. wp-blog-header.php or the wp-admin/ folder) are accessible.
3516   *
3517   * Returns the 'site_url' option with the appropriate protocol, 'https' if
3518   * is_ssl() and 'http' otherwise. If $scheme is 'http' or 'https', is_ssl() is
3519   * overridden.
3520   *
3521   * @since 3.0.0
3522   *
3523   * @param string      $path   Optional. Path relative to the site URL. Default empty.
3524   * @param string|null $scheme Optional. Scheme to give the site URL context. See set_url_scheme().
3525   * @return string Site URL link with optional path appended.
3526   */
3527  function site_url( $path = '', $scheme = null ) {
3528      return get_site_url( null, $path, $scheme );
3529  }
3530  
3531  /**
3532   * Retrieves the URL for a given site where WordPress application files
3533   * (e.g. wp-blog-header.php or the wp-admin/ folder) are accessible.
3534   *
3535   * Returns the 'site_url' option with the appropriate protocol, 'https' if
3536   * is_ssl() and 'http' otherwise. If `$scheme` is 'http' or 'https',
3537   * `is_ssl()` is overridden.
3538   *
3539   * @since 3.0.0
3540   *
3541   * @param int|null    $blog_id Optional. Site ID. Default null (current site).
3542   * @param string      $path    Optional. Path relative to the site URL. Default empty.
3543   * @param string|null $scheme  Optional. Scheme to give the site URL context. Accepts
3544   *                             'http', 'https', 'login', 'login_post', 'admin', or
3545   *                             'relative'. Default null.
3546   * @return string Site URL link with optional path appended.
3547   */
3548  function get_site_url( $blog_id = null, $path = '', $scheme = null ) {
3549      if ( empty( $blog_id ) || ! is_multisite() ) {
3550          $url = get_option( 'siteurl' );
3551      } else {
3552          switch_to_blog( $blog_id );
3553          $url = get_option( 'siteurl' );
3554          restore_current_blog();
3555      }
3556  
3557      $url = set_url_scheme( $url, $scheme );
3558  
3559      if ( $path && is_string( $path ) ) {
3560          $url .= '/' . ltrim( $path, '/' );
3561      }
3562  
3563      /**
3564       * Filters the site URL.
3565       *
3566       * @since 2.7.0
3567       *
3568       * @param string      $url     The complete site URL including scheme and path.
3569       * @param string      $path    Path relative to the site URL. Blank string if no path is specified.
3570       * @param string|null $scheme  Scheme to give the site URL context. Accepts 'http', 'https', 'login',
3571       *                             'login_post', 'admin', 'relative' or null.
3572       * @param int|null    $blog_id Site ID, or null for the current site.
3573       */
3574      return apply_filters( 'site_url', $url, $path, $scheme, $blog_id );
3575  }
3576  
3577  /**
3578   * Retrieves the URL to the admin area for the current site.
3579   *
3580   * @since 2.6.0
3581   *
3582   * @param string $path   Optional. Path relative to the admin URL. Default empty.
3583   * @param string $scheme The scheme to use. Default is 'admin', which obeys force_ssl_admin() and is_ssl().
3584   *                       'http' or 'https' can be passed to force those schemes.
3585   * @return string Admin URL link with optional path appended.
3586   */
3587  function admin_url( $path = '', $scheme = 'admin' ) {
3588      return get_admin_url( null, $path, $scheme );
3589  }
3590  
3591  /**
3592   * Retrieves the URL to the admin area for a given site.
3593   *
3594   * @since 3.0.0
3595   *
3596   * @param int|null $blog_id Optional. Site ID. Default null (current site).
3597   * @param string   $path    Optional. Path relative to the admin URL. Default empty.
3598   * @param string   $scheme  Optional. The scheme to use. Accepts 'http' or 'https',
3599   *                          to force those schemes. Default 'admin', which obeys
3600   *                          force_ssl_admin() and is_ssl().
3601   * @return string Admin URL link with optional path appended.
3602   */
3603  function get_admin_url( $blog_id = null, $path = '', $scheme = 'admin' ) {
3604      $url = get_site_url( $blog_id, 'wp-admin/', $scheme );
3605  
3606      if ( $path && is_string( $path ) ) {
3607          $url .= ltrim( $path, '/' );
3608      }
3609  
3610      /**
3611       * Filters the admin area URL.
3612       *
3613       * @since 2.8.0
3614       * @since 5.8.0 The `$scheme` parameter was added.
3615       *
3616       * @param string      $url     The complete admin area URL including scheme and path.
3617       * @param string      $path    Path relative to the admin area URL. Blank string if no path is specified.
3618       * @param int|null    $blog_id Site ID, or null for the current site.
3619       * @param string|null $scheme  The scheme to use. Accepts 'http', 'https',
3620       *                             'admin', or null. Default 'admin', which obeys force_ssl_admin() and is_ssl().
3621       */
3622      return apply_filters( 'admin_url', $url, $path, $blog_id, $scheme );
3623  }
3624  
3625  /**
3626   * Retrieves the URL to the includes directory.
3627   *
3628   * @since 2.6.0
3629   *
3630   * @param string      $path   Optional. Path relative to the includes URL. Default empty.
3631   * @param string|null $scheme Optional. Scheme to give the includes URL context. Accepts
3632   *                            'http', 'https', or 'relative'. Default null.
3633   * @return string Includes URL link with optional path appended.
3634   */
3635  function includes_url( $path = '', $scheme = null ) {
3636      $url = site_url( '/' . WPINC . '/', $scheme );
3637  
3638      if ( $path && is_string( $path ) ) {
3639          $url .= ltrim( $path, '/' );
3640      }
3641  
3642      /**
3643       * Filters the URL to the includes directory.
3644       *
3645       * @since 2.8.0
3646       * @since 5.8.0 The `$scheme` parameter was added.
3647       *
3648       * @param string      $url    The complete URL to the includes directory including scheme and path.
3649       * @param string      $path   Path relative to the URL to the wp-includes directory. Blank string
3650       *                            if no path is specified.
3651       * @param string|null $scheme Scheme to give the includes URL context. Accepts
3652       *                            'http', 'https', 'relative', or null. Default null.
3653       */
3654      return apply_filters( 'includes_url', $url, $path, $scheme );
3655  }
3656  
3657  /**
3658   * Retrieves the URL to the content directory.
3659   *
3660   * @since 2.6.0
3661   *
3662   * @param string $path Optional. Path relative to the content URL. Default empty.
3663   * @return string Content URL link with optional path appended.
3664   */
3665  function content_url( $path = '' ) {
3666      $url = set_url_scheme( WP_CONTENT_URL );
3667  
3668      if ( $path && is_string( $path ) ) {
3669          $url .= '/' . ltrim( $path, '/' );
3670      }
3671  
3672      /**
3673       * Filters the URL to the content directory.
3674       *
3675       * @since 2.8.0
3676       *
3677       * @param string $url  The complete URL to the content directory including scheme and path.
3678       * @param string $path Path relative to the URL to the content directory. Blank string
3679       *                     if no path is specified.
3680       */
3681      return apply_filters( 'content_url', $url, $path );
3682  }
3683  
3684  /**
3685   * Retrieves a URL within the plugins or mu-plugins directory.
3686   *
3687   * Defaults to the plugins directory URL if no arguments are supplied.
3688   *
3689   * @since 2.6.0
3690   *
3691   * @param string $path   Optional. Extra path appended to the end of the URL, including
3692   *                       the relative directory if $plugin is supplied. Default empty.
3693   * @param string $plugin Optional. A full path to a file inside a plugin or mu-plugin.
3694   *                       The URL will be relative to its directory. Default empty.
3695   *                       Typically this is done by passing `__FILE__` as the argument.
3696   * @return string Plugins URL link with optional paths appended.
3697   */
3698  function plugins_url( $path = '', $plugin = '' ) {
3699  
3700      $path          = wp_normalize_path( $path );
3701      $plugin        = wp_normalize_path( $plugin );
3702      $mu_plugin_dir = wp_normalize_path( WPMU_PLUGIN_DIR );
3703  
3704      if ( ! empty( $plugin ) && str_starts_with( $plugin, $mu_plugin_dir ) ) {
3705          $url = WPMU_PLUGIN_URL;
3706      } else {
3707          $url = WP_PLUGIN_URL;
3708      }
3709  
3710      $url = set_url_scheme( $url );
3711  
3712      if ( ! empty( $plugin ) && is_string( $plugin ) ) {
3713          $folder = dirname( plugin_basename( $plugin ) );
3714          if ( '.' !== $folder ) {
3715              $url .= '/' . ltrim( $folder, '/' );
3716          }
3717      }
3718  
3719      if ( $path && is_string( $path ) ) {
3720          $url .= '/' . ltrim( $path, '/' );
3721      }
3722  
3723      /**
3724       * Filters the URL to the plugins directory.
3725       *
3726       * @since 2.8.0
3727       *
3728       * @param string $url    The complete URL to the plugins directory including scheme and path.
3729       * @param string $path   Path relative to the URL to the plugins directory. Blank string
3730       *                       if no path is specified.
3731       * @param string $plugin The plugin file path to be relative to. Blank string if no plugin
3732       *                       is specified.
3733       */
3734      return apply_filters( 'plugins_url', $url, $path, $plugin );
3735  }
3736  
3737  /**
3738   * Retrieves the site URL for the current network.
3739   *
3740   * Returns the site URL with the appropriate protocol, 'https' if
3741   * is_ssl() and 'http' otherwise. If $scheme is 'http' or 'https', is_ssl() is
3742   * overridden.
3743   *
3744   * @since 3.0.0
3745   *
3746   * @see set_url_scheme()
3747   *
3748   * @param string      $path   Optional. Path relative to the site URL. Default empty.
3749   * @param string|null $scheme Optional. Scheme to give the site URL context. Accepts
3750   *                            'http', 'https', or 'relative'. Default null.
3751   * @return string Site URL link with optional path appended.
3752   */
3753  function network_site_url( $path = '', $scheme = null ) {
3754      if ( ! is_multisite() ) {
3755          return site_url( $path, $scheme );
3756      }
3757  
3758      $current_network = get_network();
3759  
3760      if ( 'relative' === $scheme ) {
3761          $url = $current_network->path;
3762      } else {
3763          $url = set_url_scheme( 'http://' . $current_network->domain . $current_network->path, $scheme );
3764      }
3765  
3766      if ( $path && is_string( $path ) ) {
3767          $url .= ltrim( $path, '/' );
3768      }
3769  
3770      /**
3771       * Filters the network site URL.
3772       *
3773       * @since 3.0.0
3774       *
3775       * @param string      $url    The complete network site URL including scheme and path.
3776       * @param string      $path   Path relative to the network site URL. Blank string if
3777       *                            no path is specified.
3778       * @param string|null $scheme Scheme to give the URL context. Accepts 'http', 'https',
3779       *                            'relative' or null.
3780       */
3781      return apply_filters( 'network_site_url', $url, $path, $scheme );
3782  }
3783  
3784  /**
3785   * Retrieves the home URL for the current network.
3786   *
3787   * Returns the home URL with the appropriate protocol, 'https' is_ssl()
3788   * and 'http' otherwise. If `$scheme` is 'http' or 'https', `is_ssl()` is
3789   * overridden.
3790   *
3791   * @since 3.0.0
3792   *
3793   * @param string      $path   Optional. Path relative to the home URL. Default empty.
3794   * @param string|null $scheme Optional. Scheme to give the home URL context. Accepts
3795   *                            'http', 'https', or 'relative'. Default null.
3796   * @return string Home URL link with optional path appended.
3797   */
3798  function network_home_url( $path = '', $scheme = null ) {
3799      if ( ! is_multisite() ) {
3800          return home_url( $path, $scheme );
3801      }
3802  
3803      $current_network = get_network();
3804      $orig_scheme     = $scheme;
3805  
3806      if ( ! in_array( $scheme, array( 'http', 'https', 'relative' ), true ) ) {
3807          $scheme = is_ssl() ? 'https' : 'http';
3808      }
3809  
3810      if ( 'relative' === $scheme ) {
3811          $url = $current_network->path;
3812      } else {
3813          $url = set_url_scheme( 'http://' . $current_network->domain . $current_network->path, $scheme );
3814      }
3815  
3816      if ( $path && is_string( $path ) ) {
3817          $url .= ltrim( $path, '/' );
3818      }
3819  
3820      /**
3821       * Filters the network home URL.
3822       *
3823       * @since 3.0.0
3824       *
3825       * @param string      $url         The complete network home URL including scheme and path.
3826       * @param string      $path        Path relative to the network home URL. Blank string
3827       *                                 if no path is specified.
3828       * @param string|null $orig_scheme Scheme to give the URL context. Accepts 'http', 'https',
3829       *                                 'relative' or null.
3830       */
3831      return apply_filters( 'network_home_url', $url, $path, $orig_scheme );
3832  }
3833  
3834  /**
3835   * Retrieves the URL to the admin area for the network.
3836   *
3837   * @since 3.0.0
3838   *
3839   * @param string $path   Optional path relative to the admin URL. Default empty.
3840   * @param string $scheme Optional. The scheme to use. Default is 'admin', which obeys force_ssl_admin()
3841   *                       and is_ssl(). 'http' or 'https' can be passed to force those schemes.
3842   * @return string Admin URL link with optional path appended.
3843   */
3844  function network_admin_url( $path = '', $scheme = 'admin' ) {
3845      if ( ! is_multisite() ) {
3846          return admin_url( $path, $scheme );
3847      }
3848  
3849      $url = network_site_url( 'wp-admin/network/', $scheme );
3850  
3851      if ( $path && is_string( $path ) ) {
3852          $url .= ltrim( $path, '/' );
3853      }
3854  
3855      /**
3856       * Filters the network admin URL.
3857       *
3858       * @since 3.0.0
3859       * @since 5.8.0 The `$scheme` parameter was added.
3860       *
3861       * @param string      $url    The complete network admin URL including scheme and path.
3862       * @param string      $path   Path relative to the network admin URL. Blank string if
3863       *                            no path is specified.
3864       * @param string|null $scheme The scheme to use. Accepts 'http', 'https',
3865       *                            'admin', or null. Default is 'admin', which obeys force_ssl_admin() and is_ssl().
3866       */
3867      return apply_filters( 'network_admin_url', $url, $path, $scheme );
3868  }
3869  
3870  /**
3871   * Retrieves the URL to the admin area for the current user.
3872   *
3873   * @since 3.0.0
3874   *
3875   * @param string $path   Optional. Path relative to the admin URL. Default empty.
3876   * @param string $scheme Optional. The scheme to use. Default is 'admin', which obeys force_ssl_admin()
3877   *                       and is_ssl(). 'http' or 'https' can be passed to force those schemes.
3878   * @return string Admin URL link with optional path appended.
3879   */
3880  function user_admin_url( $path = '', $scheme = 'admin' ) {
3881      $url = network_site_url( 'wp-admin/user/', $scheme );
3882  
3883      if ( $path && is_string( $path ) ) {
3884          $url .= ltrim( $path, '/' );
3885      }
3886  
3887      /**
3888       * Filters the user admin URL for the current user.
3889       *
3890       * @since 3.1.0
3891       * @since 5.8.0 The `$scheme` parameter was added.
3892       *
3893       * @param string      $url    The complete URL including scheme and path.
3894       * @param string      $path   Path relative to the URL. Blank string if
3895       *                            no path is specified.
3896       * @param string|null $scheme The scheme to use. Accepts 'http', 'https',
3897       *                            'admin', or null. Default is 'admin', which obeys force_ssl_admin() and is_ssl().
3898       */
3899      return apply_filters( 'user_admin_url', $url, $path, $scheme );
3900  }
3901  
3902  /**
3903   * Retrieves the URL to the admin area for either the current site or the network depending on context.
3904   *
3905   * @since 3.1.0
3906   *
3907   * @param string $path   Optional. Path relative to the admin URL. Default empty.
3908   * @param string $scheme Optional. The scheme to use. Default is 'admin', which obeys force_ssl_admin()
3909   *                       and is_ssl(). 'http' or 'https' can be passed to force those schemes.
3910   * @return string Admin URL link with optional path appended.
3911   */
3912  function self_admin_url( $path = '', $scheme = 'admin' ) {
3913      if ( is_network_admin() ) {
3914          $url = network_admin_url( $path, $scheme );
3915      } elseif ( is_user_admin() ) {
3916          $url = user_admin_url( $path, $scheme );
3917      } else {
3918          $url = admin_url( $path, $scheme );
3919      }
3920  
3921      /**
3922       * Filters the admin URL for the current site or network depending on context.
3923       *
3924       * @since 4.9.0
3925       *
3926       * @param string $url    The complete URL including scheme and path.
3927       * @param string $path   Path relative to the URL. Blank string if no path is specified.
3928       * @param string $scheme The scheme to use.
3929       */
3930      return apply_filters( 'self_admin_url', $url, $path, $scheme );
3931  }
3932  
3933  /**
3934   * Sets the scheme for a URL.
3935   *
3936   * @since 3.4.0
3937   * @since 4.4.0 The 'rest' scheme was added.
3938   *
3939   * @param string      $url    Absolute URL that includes a scheme
3940   * @param string|null $scheme Optional. Scheme to give $url. Currently 'http', 'https', 'login',
3941   *                            'login_post', 'admin', 'relative', 'rest', 'rpc', or null. Default null.
3942   * @return string URL with chosen scheme.
3943   */
3944  function set_url_scheme( $url, $scheme = null ) {
3945      $orig_scheme = $scheme;
3946  
3947      if ( ! $scheme ) {
3948          $scheme = is_ssl() ? 'https' : 'http';
3949      } elseif ( 'admin' === $scheme || 'login' === $scheme || 'login_post' === $scheme || 'rpc' === $scheme ) {
3950          $scheme = is_ssl() || force_ssl_admin() ? 'https' : 'http';
3951      } elseif ( 'http' !== $scheme && 'https' !== $scheme && 'relative' !== $scheme ) {
3952          $scheme = is_ssl() ? 'https' : 'http';
3953      }
3954  
3955      $url = trim( $url );
3956      if ( str_starts_with( $url, '//' ) ) {
3957          $url = 'http:' . $url;
3958      }
3959  
3960      if ( 'relative' === $scheme ) {
3961          $url = ltrim( preg_replace( '#^\w+://[^/]*#', '', $url ) );
3962          if ( '' !== $url && '/' === $url[0] ) {
3963              $url = '/' . ltrim( $url, "/ \t\n\r\0\x0B" );
3964          }
3965      } else {
3966          $url = preg_replace( '#^\w+://#', $scheme . '://', $url );
3967      }
3968  
3969      /**
3970       * Filters the resulting URL after setting the scheme.
3971       *
3972       * @since 3.4.0
3973       *
3974       * @param string      $url         The complete URL including scheme and path.
3975       * @param string      $scheme      Scheme applied to the URL. One of 'http', 'https', or 'relative'.
3976       * @param string|null $orig_scheme Scheme requested for the URL. One of 'http', 'https', 'login',
3977       *                                 'login_post', 'admin', 'relative', 'rest', 'rpc', or null.
3978       */
3979      return apply_filters( 'set_url_scheme', $url, $scheme, $orig_scheme );
3980  }
3981  
3982  /**
3983   * Retrieves the URL to the user's dashboard.
3984   *
3985   * If a user does not belong to any site, the global user dashboard is used. If the user
3986   * belongs to the current site, the dashboard for the current site is returned. If the user
3987   * cannot edit the current site, the dashboard to the user's primary site is returned.
3988   *
3989   * @since 3.1.0
3990   *
3991   * @param int    $user_id Optional. User ID. Defaults to current user.
3992   * @param string $path    Optional path relative to the dashboard. Use only paths known to
3993   *                        both site and user admins. Default empty.
3994   * @param string $scheme  The scheme to use. Default is 'admin', which obeys force_ssl_admin()
3995   *                        and is_ssl(). 'http' or 'https' can be passed to force those schemes.
3996   * @return string Dashboard URL link with optional path appended.
3997   */
3998  function get_dashboard_url( $user_id = 0, $path = '', $scheme = 'admin' ) {
3999      $user_id = $user_id ? (int) $user_id : get_current_user_id();
4000  
4001      $blogs = get_blogs_of_user( $user_id );
4002  
4003      if ( is_multisite() && ! user_can( $user_id, 'manage_network' ) && empty( $blogs ) ) {
4004          $url = user_admin_url( $path, $scheme );
4005      } elseif ( ! is_multisite() ) {
4006          $url = admin_url( $path, $scheme );
4007      } else {
4008          $current_blog = get_current_blog_id();
4009  
4010          if ( $current_blog && ( user_can( $user_id, 'manage_network' ) || isset( $blogs[ $current_blog ] ) ) ) {
4011              $url = admin_url( $path, $scheme );
4012          } else {
4013              $active = get_active_blog_for_user( $user_id );
4014              if ( $active ) {
4015                  $url = get_admin_url( $active->blog_id, $path, $scheme );
4016              } else {
4017                  $url = user_admin_url( $path, $scheme );
4018              }
4019          }
4020      }
4021  
4022      /**
4023       * Filters the dashboard URL for a user.
4024       *
4025       * @since 3.1.0
4026       *
4027       * @param string $url     The complete URL including scheme and path.
4028       * @param int    $user_id The user ID.
4029       * @param string $path    Path relative to the URL. Blank string if no path is specified.
4030       * @param string $scheme  Scheme to give the URL context. Accepts 'http', 'https', 'login',
4031       *                        'login_post', 'admin', 'relative' or null.
4032       */
4033      return apply_filters( 'user_dashboard_url', $url, $user_id, $path, $scheme );
4034  }
4035  
4036  /**
4037   * Retrieves the URL to the user's profile editor.
4038   *
4039   * @since 3.1.0
4040   *
4041   * @param int    $user_id Optional. User ID. Defaults to current user.
4042   * @param string $scheme  Optional. The scheme to use. Default is 'admin', which obeys force_ssl_admin()
4043   *                        and is_ssl(). 'http' or 'https' can be passed to force those schemes.
4044   * @return string Dashboard URL link with optional path appended.
4045   */
4046  function get_edit_profile_url( $user_id = 0, $scheme = 'admin' ) {
4047      $user_id = $user_id ? (int) $user_id : get_current_user_id();
4048  
4049      if ( is_user_admin() ) {
4050          $url = user_admin_url( 'profile.php', $scheme );
4051      } elseif ( is_network_admin() ) {
4052          $url = network_admin_url( 'profile.php', $scheme );
4053      } else {
4054          $url = get_dashboard_url( $user_id, 'profile.php', $scheme );
4055      }
4056  
4057      /**
4058       * Filters the URL for a user's profile editor.
4059       *
4060       * @since 3.1.0
4061       *
4062       * @param string $url     The complete URL including scheme and path.
4063       * @param int    $user_id The user ID.
4064       * @param string $scheme  Scheme to give the URL context. Accepts 'http', 'https', 'login',
4065       *                        'login_post', 'admin', 'relative' or null.
4066       */
4067      return apply_filters( 'edit_profile_url', $url, $user_id, $scheme );
4068  }
4069  
4070  /**
4071   * Returns the canonical URL for a post.
4072   *
4073   * When the post is the same as the current requested page the function will handle the
4074   * pagination arguments too.
4075   *
4076   * @since 4.6.0
4077   *
4078   * @param int|WP_Post $post Optional. Post ID or object. Default is global `$post`.
4079   * @return string|false The canonical URL. False if the post does not exist
4080   *                      or has not been published yet.
4081   */
4082  function wp_get_canonical_url( $post = null ) {
4083      $post = get_post( $post );
4084  
4085      if ( ! $post ) {
4086          return false;
4087      }
4088  
4089      if ( 'publish' !== get_post_status( $post ) ) {
4090          return false;
4091      }
4092  
4093      $canonical_url = get_permalink( $post );
4094  
4095      // If a canonical is being generated for the current page, make sure it has pagination if needed.
4096      if ( get_queried_object_id() === $post->ID ) {
4097          $page = get_query_var( 'page', 0 );
4098          if ( $page >= 2 ) {
4099              if ( ! get_option( 'permalink_structure' ) ) {
4100                  $canonical_url = add_query_arg( 'page', $page, $canonical_url );
4101              } else {
4102                  $canonical_url = trailingslashit( $canonical_url ) . user_trailingslashit( $page, 'single_paged' );
4103              }
4104          }
4105  
4106          $cpage = get_query_var( 'cpage', 0 );
4107          if ( $cpage ) {
4108              $canonical_url = get_comments_pagenum_link( $cpage );
4109          }
4110      }
4111  
4112      /**
4113       * Filters the canonical URL for a post.
4114       *
4115       * @since 4.6.0
4116       *
4117       * @param string  $canonical_url The post's canonical URL.
4118       * @param WP_Post $post          Post object.
4119       */
4120      return apply_filters( 'get_canonical_url', $canonical_url, $post );
4121  }
4122  
4123  /**
4124   * Outputs rel=canonical for singular queries.
4125   *
4126   * @since 2.9.0
4127   * @since 4.6.0 Adjusted to use `wp_get_canonical_url()`.
4128   */
4129  function rel_canonical() {
4130      if ( ! is_singular() ) {
4131          return;
4132      }
4133  
4134      $id = get_queried_object_id();
4135  
4136      if ( 0 === $id ) {
4137          return;
4138      }
4139  
4140      $url = wp_get_canonical_url( $id );
4141  
4142      if ( ! empty( $url ) ) {
4143          echo '<link rel="canonical" href="' . esc_url( $url ) . '" />' . "\n";
4144      }
4145  }
4146  
4147  /**
4148   * Returns a shortlink for a post, page, attachment, or site.
4149   *
4150   * This function exists to provide a shortlink tag that all themes and plugins can target.
4151   * A plugin must hook in to provide the actual shortlinks. Default shortlink support is
4152   * limited to providing ?p= style links for posts. Plugins can short-circuit this function
4153   * via the {@see 'pre_get_shortlink'} filter or filter the output via the {@see 'get_shortlink'}
4154   * filter.
4155   *
4156   * @since 3.0.0
4157   *
4158   * @param int    $id          Optional. A post or site ID. Default is 0, which means the current post or site.
4159   * @param string $context     Optional. Whether the ID is a 'site' ID, 'post' ID, or 'media' ID. If 'post',
4160   *                            the post_type of the post is consulted. If 'query', the current query is consulted
4161   *                            to determine the ID and context. Default 'post'.
4162   * @param bool   $allow_slugs Optional. Whether to allow post slugs in the shortlink. It is up to the plugin how
4163   *                            and whether to honor this. Default true.
4164   * @return string A shortlink or an empty string if no shortlink exists for the requested resource or if shortlinks
4165   *                are not enabled.
4166   */
4167  function wp_get_shortlink( $id = 0, $context = 'post', $allow_slugs = true ) {
4168      /**
4169       * Filters whether to preempt generating a shortlink for the given post.
4170       *
4171       * Returning a value other than false from the filter will short-circuit
4172       * the shortlink generation process, returning that value instead.
4173       *
4174       * @since 3.0.0
4175       *
4176       * @param false|string $return      Short-circuit return value. Either false or a URL string.
4177       * @param int          $id          Post ID, or 0 for the current post.
4178       * @param string       $context     The context for the link. One of 'post' or 'query',
4179       * @param bool         $allow_slugs Whether to allow post slugs in the shortlink.
4180       */
4181      $shortlink = apply_filters( 'pre_get_shortlink', false, $id, $context, $allow_slugs );
4182  
4183      if ( false !== $shortlink ) {
4184          return $shortlink;
4185      }
4186  
4187      $post_id = 0;
4188      if ( 'query' === $context && is_singular() ) {
4189          $post_id = get_queried_object_id();
4190          $post    = get_post( $post_id );
4191      } elseif ( 'post' === $context ) {
4192          $post = get_post( $id );
4193          if ( ! empty( $post->ID ) ) {
4194              $post_id = $post->ID;
4195          }
4196      }
4197  
4198      $shortlink = '';
4199  
4200      // Return `?p=` link for all public post types.
4201      if ( ! empty( $post_id ) ) {
4202          $post_type = get_post_type_object( $post->post_type );
4203  
4204          if ( 'page' === $post->post_type
4205              && 'page' === get_option( 'show_on_front' ) && (int) get_option( 'page_on_front' ) === $post->ID
4206          ) {
4207              $shortlink = home_url( '/' );
4208          } elseif ( $post_type && $post_type->public ) {
4209              $shortlink = home_url( '?p=' . $post_id );
4210          }
4211      }
4212  
4213      /**
4214       * Filters the shortlink for a post.
4215       *
4216       * @since 3.0.0
4217       *
4218       * @param string $shortlink   Shortlink URL.
4219       * @param int    $id          Post ID, or 0 for the current post.
4220       * @param string $context     The context for the link. One of 'post' or 'query',
4221       * @param bool   $allow_slugs Whether to allow post slugs in the shortlink. Not used by default.
4222       */
4223      return apply_filters( 'get_shortlink', $shortlink, $id, $context, $allow_slugs );
4224  }
4225  
4226  /**
4227   * Injects rel=shortlink into the head if a shortlink is defined for the current page.
4228   *
4229   * Attached to the {@see 'wp_head'} action.
4230   *
4231   * @since 3.0.0
4232   */
4233  function wp_shortlink_wp_head() {
4234      $shortlink = wp_get_shortlink( 0, 'query' );
4235  
4236      if ( empty( $shortlink ) ) {
4237          return;
4238      }
4239  
4240      echo "<link rel='shortlink' href='" . esc_url( $shortlink ) . "' />\n";
4241  }
4242  
4243  /**
4244   * Sends a Link: rel=shortlink header if a shortlink is defined for the current page.
4245   *
4246   * Attached to the {@see 'wp'} action.
4247   *
4248   * @since 3.0.0
4249   */
4250  function wp_shortlink_header() {
4251      if ( headers_sent() ) {
4252          return;
4253      }
4254  
4255      $shortlink = wp_get_shortlink( 0, 'query' );
4256  
4257      if ( empty( $shortlink ) ) {
4258          return;
4259      }
4260  
4261      header( 'Link: <' . $shortlink . '>; rel=shortlink', false );
4262  }
4263  
4264  /**
4265   * Displays the shortlink for a post.
4266   *
4267   * Must be called from inside "The Loop"
4268   *
4269   * Call like the_shortlink( __( 'Shortlinkage FTW' ) )
4270   *
4271   * @since 3.0.0
4272   * @since 6.8.0 Removed title attribute.
4273   *
4274   * @param string $text   Optional. The link text or HTML to be displayed. Defaults to 'This is the short link.'
4275   * @param string $title  Unused.
4276   * @param string $before Optional. HTML to display before the link. Default empty.
4277   * @param string $after  Optional. HTML to display after the link. Default empty.
4278   */
4279  function the_shortlink( $text = '', $title = '', $before = '', $after = '' ) {
4280      $post = get_post();
4281  
4282      if ( empty( $text ) ) {
4283          $text = __( 'This is the short link.' );
4284      }
4285  
4286      $shortlink = wp_get_shortlink( $post->ID );
4287  
4288      if ( ! empty( $shortlink ) ) {
4289          $link = '<a rel="shortlink" href="' . esc_url( $shortlink ) . '">' . $text . '</a>';
4290  
4291          /**
4292           * Filters the short link anchor tag for a post.
4293           *
4294           * @since 3.0.0
4295           *
4296           * @param string $link      Shortlink anchor tag.
4297           * @param string $shortlink Shortlink URL.
4298           * @param string $text      Shortlink's text.
4299           * @param string $title     Shortlink's title attribute. Unused.
4300           */
4301          $link = apply_filters( 'the_shortlink', $link, $shortlink, $text, $title );
4302          echo $before, $link, $after;
4303      }
4304  }
4305  
4306  /**
4307   * Retrieves the avatar URL.
4308   *
4309   * @since 4.2.0
4310   *
4311   * @param mixed $id_or_email The avatar to retrieve a URL for. Accepts a user ID, Gravatar SHA-256 or MD5 hash,
4312   *                           user email, WP_User object, WP_Post object, or WP_Comment object.
4313   * @param array $args {
4314   *     Optional. Arguments to use instead of the default arguments.
4315   *
4316   *     @type int    $size           Height and width of the avatar in pixels. Default 96.
4317   *     @type string $default        URL for the default image or a default type. Accepts:
4318   *                                  - '404' (return a 404 instead of a default image)
4319   *                                  - 'retro' (a 8-bit arcade-style pixelated face)
4320   *                                  - 'robohash' (a robot)
4321   *                                  - 'monsterid' (a monster)
4322   *                                  - 'wavatar' (a cartoon face)
4323   *                                  - 'identicon' (the "quilt", a geometric pattern)
4324   *                                  - 'initials' (initials based avatar with background color)
4325   *                                  - 'color' (generated background color)
4326   *                                  - 'mystery', 'mm', or 'mysteryman' (The Oyster Man)
4327   *                                  - 'blank' (transparent GIF)
4328   *                                  - 'gravatar_default' (the Gravatar logo)
4329   *                                  Default is the value of the 'avatar_default' option,
4330   *                                  with a fallback of 'mystery'.
4331   *     @type bool   $force_default  Whether to always show the default image, never the Gravatar.
4332   *                                  Default false.
4333   *     @type string $rating         What rating to display avatars up to. Accepts:
4334   *                                  - 'G' (suitable for all audiences)
4335   *                                  - 'PG' (possibly offensive, usually for audiences 13 and above)
4336   *                                  - 'R' (intended for adult audiences above 17)
4337   *                                  - 'X' (even more mature than above)
4338   *                                  Default is the value of the 'avatar_rating' option.
4339   *     @type string $scheme         URL scheme to use. See set_url_scheme() for accepted values.
4340   *                                  Default null.
4341   *     @type array  $processed_args When the function returns, the value will be the processed/sanitized $args
4342   *                                  plus a "found_avatar" guess. Pass as a reference. Default null.
4343   * }
4344   * @return string|false The URL of the avatar on success, false on failure.
4345   */
4346  function get_avatar_url( $id_or_email, $args = null ) {
4347      $args = get_avatar_data( $id_or_email, $args );
4348      return $args['url'];
4349  }
4350  
4351  /**
4352   * Check if this comment type allows avatars to be retrieved.
4353   *
4354   * @since 5.1.0
4355   *
4356   * @param string $comment_type Comment type to check.
4357   * @return bool Whether the comment type is allowed for retrieving avatars.
4358   */
4359  function is_avatar_comment_type( $comment_type ) {
4360      /**
4361       * Filters the list of allowed comment types for retrieving avatars.
4362       *
4363       * @since 3.0.0
4364       *
4365       * @since 6.9.0 The 'note' comment type was added.
4366       *
4367       * @param array $types An array of content types. Default contains 'comment' and 'note'.
4368       */
4369      $allowed_comment_types = apply_filters( 'get_avatar_comment_types', array( 'comment', 'note' ) );
4370  
4371      return in_array( $comment_type, (array) $allowed_comment_types, true );
4372  }
4373  
4374  /**
4375   * Retrieves default data about the avatar.
4376   *
4377   * @since 4.2.0
4378   * @since 6.7.0 Gravatar URLs always use HTTPS.
4379   * @since 6.8.0 Gravatar URLs use the SHA-256 hashing algorithm.
4380   *
4381   * @param mixed $id_or_email The avatar to retrieve. Accepts a user ID, Gravatar SHA-256 or MD5 hash,
4382   *                           user email, WP_User object, WP_Post object, or WP_Comment object.
4383   * @param array $args {
4384   *     Optional. Arguments to use instead of the default arguments.
4385   *
4386   *     @type int    $size           Height and width of the avatar in pixels. Default 96.
4387   *     @type int    $height         Display height of the avatar in pixels. Defaults to $size.
4388   *     @type int    $width          Display width of the avatar in pixels. Defaults to $size.
4389   *     @type string $default        URL for the default image or a default type. Accepts:
4390   *                                  - '404' (return a 404 instead of a default image)
4391   *                                  - 'retro' (a 8-bit arcade-style pixelated face)
4392   *                                  - 'robohash' (a robot)
4393   *                                  - 'monsterid' (a monster)
4394   *                                  - 'wavatar' (a cartoon face)
4395   *                                  - 'identicon' (the "quilt", a geometric pattern)
4396   *                                  - 'initials' (initials based avatar with background color)
4397   *                                  - 'color' (generated background color)
4398   *                                  - 'mystery', 'mm', or 'mysteryman' (The Oyster Man)
4399   *                                  - 'blank' (transparent GIF)
4400   *                                  - 'gravatar_default' (the Gravatar logo)
4401   *                                  Default is the value of the 'avatar_default' option,
4402   *                                  with a fallback of 'mystery'.
4403   *     @type bool   $force_default  Whether to always show the default image, never the Gravatar.
4404   *                                  Default false.
4405   *     @type string $rating         What rating to display avatars up to. Accepts:
4406   *                                  - 'G' (suitable for all audiences)
4407   *                                  - 'PG' (possibly offensive, usually for audiences 13 and above)
4408   *                                  - 'R' (intended for adult audiences above 17)
4409   *                                  - 'X' (even more mature than above)
4410   *                                  Default is the value of the 'avatar_rating' option.
4411   *     @type string $scheme         URL scheme to use. See set_url_scheme() for accepted values.
4412   *                                  For Gravatars this setting is ignored and HTTPS is used to avoid
4413   *                                  unnecessary redirects. The setting is retained for systems using
4414   *                                  the {@see 'pre_get_avatar_data'} filter to customize avatars.
4415   *                                  Default null.
4416   *     @type array  $processed_args When the function returns, the value will be the processed/sanitized $args
4417   *                                  plus a "found_avatar" guess. Pass as a reference. Default null.
4418   *     @type string $extra_attr     HTML attributes to insert in the IMG element. Is not sanitized.
4419   *                                  Default empty.
4420   * }
4421   * @return array {
4422   *     Along with the arguments passed in `$args`, this will contain a couple of extra arguments.
4423   *
4424   *     @type bool         $found_avatar True if an avatar was found for this user,
4425   *                                      false or not set if none was found.
4426   *     @type string|false $url          The URL of the avatar that was found, or false.
4427   * }
4428   */
4429  function get_avatar_data( $id_or_email, $args = null ) {
4430      $args = wp_parse_args(
4431          $args,
4432          array(
4433              'size'           => 96,
4434              'height'         => null,
4435              'width'          => null,
4436              'default'        => get_option( 'avatar_default', 'mystery' ),
4437              'force_default'  => false,
4438              'rating'         => get_option( 'avatar_rating' ),
4439              'scheme'         => null,
4440              'processed_args' => null, // If used, should be a reference.
4441              'extra_attr'     => '',
4442          )
4443      );
4444  
4445      if ( is_numeric( $args['size'] ) ) {
4446          $args['size'] = absint( $args['size'] );
4447          if ( ! $args['size'] ) {
4448              $args['size'] = 96;
4449          }
4450      } else {
4451          $args['size'] = 96;
4452      }
4453  
4454      if ( is_numeric( $args['height'] ) ) {
4455          $args['height'] = absint( $args['height'] );
4456          if ( ! $args['height'] ) {
4457              $args['height'] = $args['size'];
4458          }
4459      } else {
4460          $args['height'] = $args['size'];
4461      }
4462  
4463      if ( is_numeric( $args['width'] ) ) {
4464          $args['width'] = absint( $args['width'] );
4465          if ( ! $args['width'] ) {
4466              $args['width'] = $args['size'];
4467          }
4468      } else {
4469          $args['width'] = $args['size'];
4470      }
4471  
4472      if ( empty( $args['default'] ) ) {
4473          $args['default'] = get_option( 'avatar_default', 'mystery' );
4474      }
4475  
4476      switch ( $args['default'] ) {
4477          case 'mm':
4478          case 'mystery':
4479          case 'mysteryman':
4480              $args['default'] = 'mm';
4481              break;
4482          case 'gravatar_default':
4483              $args['default'] = false;
4484              break;
4485      }
4486  
4487      $args['force_default'] = (bool) $args['force_default'];
4488  
4489      $args['rating'] = strtolower( $args['rating'] );
4490  
4491      $args['found_avatar'] = false;
4492  
4493      /**
4494       * Filters whether to retrieve the avatar URL early.
4495       *
4496       * Passing a non-null value in the 'url' member of the return array will
4497       * effectively short circuit get_avatar_data(), passing the value through
4498       * the {@see 'get_avatar_data'} filter and returning early.
4499       *
4500       * @since 4.2.0
4501       *
4502       * @param array $args        Arguments passed to get_avatar_data(), after processing.
4503       * @param mixed $id_or_email The avatar to retrieve. Accepts a user ID, Gravatar SHA-256 or MD5 hash,
4504       *                           user email, WP_User object, WP_Post object, or WP_Comment object.
4505       */
4506      $args = apply_filters( 'pre_get_avatar_data', $args, $id_or_email );
4507  
4508      if ( isset( $args['url'] ) ) {
4509          /** This filter is documented in wp-includes/link-template.php */
4510          return apply_filters( 'get_avatar_data', $args, $id_or_email );
4511      }
4512  
4513      $email_hash = '';
4514      $user       = false;
4515      $email      = false;
4516  
4517      if ( is_object( $id_or_email ) && isset( $id_or_email->comment_ID ) ) {
4518          $id_or_email = get_comment( $id_or_email );
4519      }
4520  
4521      // Process the user identifier.
4522      if ( is_numeric( $id_or_email ) ) {
4523          $user = get_user_by( 'id', absint( $id_or_email ) );
4524      } elseif ( is_string( $id_or_email ) ) {
4525          if ( str_contains( $id_or_email, '@sha256.gravatar.com' ) ) {
4526              // SHA-256 hash.
4527              list( $email_hash ) = explode( '@', $id_or_email );
4528          } elseif ( str_contains( $id_or_email, '@md5.gravatar.com' ) ) {
4529              // MD5 hash.
4530              list( $email_hash ) = explode( '@', $id_or_email );
4531          } else {
4532              // Email address.
4533              $email = $id_or_email;
4534          }
4535      } elseif ( $id_or_email instanceof WP_User ) {
4536          // User object.
4537          $user = $id_or_email;
4538      } elseif ( $id_or_email instanceof WP_Post ) {
4539          // Post object.
4540          $user = get_user_by( 'id', (int) $id_or_email->post_author );
4541      } elseif ( $id_or_email instanceof WP_Comment ) {
4542          if ( ! is_avatar_comment_type( get_comment_type( $id_or_email ) ) ) {
4543              $args['url'] = false;
4544              /** This filter is documented in wp-includes/link-template.php */
4545              return apply_filters( 'get_avatar_data', $args, $id_or_email );
4546          }
4547  
4548          if ( ! empty( $id_or_email->user_id ) ) {
4549              $user = get_user_by( 'id', (int) $id_or_email->user_id );
4550          }
4551          if ( ( ! $user || is_wp_error( $user ) ) && ! empty( $id_or_email->comment_author_email ) ) {
4552              $email = $id_or_email->comment_author_email;
4553          }
4554      }
4555  
4556      if ( ! $email_hash ) {
4557          if ( $user ) {
4558              $email = $user->user_email;
4559          }
4560  
4561          if ( $email ) {
4562              $email_hash = hash( 'sha256', strtolower( trim( $email ) ) );
4563          }
4564      }
4565  
4566      if ( $email_hash ) {
4567          $args['found_avatar'] = true;
4568      }
4569  
4570      $url_args = array(
4571          's' => $args['size'],
4572          'd' => $args['default'],
4573          'f' => $args['force_default'] ? 'y' : false,
4574          'r' => $args['rating'],
4575      );
4576  
4577      // Handle additional parameters for the 'initials' avatar type.
4578      if ( 'initials' === $args['default'] ) {
4579          $name = '';
4580  
4581          if ( $user ) {
4582              if ( '' !== $user->display_name ) {
4583                  $name = $user->display_name;
4584              } elseif ( '' !== $user->first_name && '' !== $user->last_name ) {
4585                  $name = sprintf(
4586                      /* translators: 1: User's first name, 2: Last name. */
4587                      _x( '%1$s %2$s', 'Display name based on first name and last name' ),
4588                      $user->first_name,
4589                      $user->last_name
4590                  );
4591              } else {
4592                  $name = $user->user_login;
4593              }
4594          } elseif ( $id_or_email instanceof WP_Comment ) {
4595              $name = $id_or_email->comment_author;
4596          } elseif ( is_string( $id_or_email ) && str_contains( $id_or_email, '@' ) ) {
4597              $name = str_replace( array( '.', '_', '-' ), ' ', substr( $id_or_email, 0, strpos( $id_or_email, '@' ) ) );
4598          }
4599  
4600          if ( '' !== $name ) {
4601              if ( ! str_contains( $name, ' ' ) || preg_match( '/\p{Han}|\p{Hiragana}|\p{Katakana}|\p{Hangul}/u', $name ) ) {
4602                  $initials = mb_substr( $name, 0, min( 2, mb_strlen( $name, 'UTF-8' ) ), 'UTF-8' );
4603              } else {
4604                  $first    = mb_substr( $name, 0, 1, 'UTF-8' );
4605                  $last     = mb_substr( $name, strrpos( $name, ' ' ) + 1, 1, 'UTF-8' );
4606                  $initials = $first . $last;
4607              }
4608  
4609              $url_args['initials'] = $initials;
4610          }
4611      }
4612  
4613      /*
4614       * Gravatars are always served over HTTPS.
4615       *
4616       * The Gravatar website redirects HTTP requests to HTTPS URLs so always
4617       * use the HTTPS scheme to avoid unnecessary redirects.
4618       */
4619      $url = 'https://secure.gravatar.com/avatar/' . $email_hash;
4620  
4621      $url = add_query_arg(
4622          rawurlencode_deep( array_filter( $url_args ) ),
4623          $url
4624      );
4625  
4626      /**
4627       * Filters the avatar URL.
4628       *
4629       * @since 4.2.0
4630       *
4631       * @param string $url         The URL of the avatar.
4632       * @param mixed  $id_or_email The avatar to retrieve. Accepts a user ID, Gravatar SHA-256 or MD5 hash,
4633       *                            user email, WP_User object, WP_Post object, or WP_Comment object.
4634       * @param array  $args        Arguments passed to get_avatar_data(), after processing.
4635       */
4636      $args['url'] = apply_filters( 'get_avatar_url', $url, $id_or_email, $args );
4637  
4638      /**
4639       * Filters the avatar data.
4640       *
4641       * @since 4.2.0
4642       *
4643       * @param array $args        Arguments passed to get_avatar_data(), after processing.
4644       * @param mixed $id_or_email The avatar to retrieve. Accepts a user ID, Gravatar SHA-256 or MD5 hash,
4645       *                           user email, WP_User object, WP_Post object, or WP_Comment object.
4646       */
4647      return apply_filters( 'get_avatar_data', $args, $id_or_email );
4648  }
4649  
4650  /**
4651   * Retrieves the URL of a file in the theme.
4652   *
4653   * Searches in the stylesheet directory before the template directory so themes
4654   * which inherit from a parent theme can just override one file.
4655   *
4656   * @since 4.7.0
4657   *
4658   * @param string $file Optional. File to search for in the stylesheet directory.
4659   * @return string The URL of the file.
4660   */
4661  function get_theme_file_uri( $file = '' ) {
4662      $file = ltrim( $file, '/' );
4663  
4664      $stylesheet_directory = get_stylesheet_directory();
4665  
4666      if ( empty( $file ) ) {
4667          $url = get_stylesheet_directory_uri();
4668      } elseif ( get_template_directory() !== $stylesheet_directory && file_exists( $stylesheet_directory . '/' . $file ) ) {
4669          $url = get_stylesheet_directory_uri() . '/' . $file;
4670      } else {
4671          $url = get_template_directory_uri() . '/' . $file;
4672      }
4673  
4674      /**
4675       * Filters the URL to a file in the theme.
4676       *
4677       * @since 4.7.0
4678       *
4679       * @param string $url  The file URL.
4680       * @param string $file The requested file to search for.
4681       */
4682      return apply_filters( 'theme_file_uri', $url, $file );
4683  }
4684  
4685  /**
4686   * Retrieves the URL of a file in the parent theme.
4687   *
4688   * @since 4.7.0
4689   *
4690   * @param string $file Optional. File to return the URL for in the template directory.
4691   * @return string The URL of the file.
4692   */
4693  function get_parent_theme_file_uri( $file = '' ) {
4694      $file = ltrim( $file, '/' );
4695  
4696      if ( empty( $file ) ) {
4697          $url = get_template_directory_uri();
4698      } else {
4699          $url = get_template_directory_uri() . '/' . $file;
4700      }
4701  
4702      /**
4703       * Filters the URL to a file in the parent theme.
4704       *
4705       * @since 4.7.0
4706       *
4707       * @param string $url  The file URL.
4708       * @param string $file The requested file to search for.
4709       */
4710      return apply_filters( 'parent_theme_file_uri', $url, $file );
4711  }
4712  
4713  /**
4714   * Retrieves the path of a file in the theme.
4715   *
4716   * Searches in the stylesheet directory before the template directory so themes
4717   * which inherit from a parent theme can just override one file.
4718   *
4719   * @since 4.7.0
4720   *
4721   * @param string $file Optional. File to search for in the stylesheet directory.
4722   * @return string The path of the file.
4723   */
4724  function get_theme_file_path( $file = '' ) {
4725      $file = ltrim( $file, '/' );
4726  
4727      $stylesheet_directory = get_stylesheet_directory();
4728      $template_directory   = get_template_directory();
4729  
4730      if ( empty( $file ) ) {
4731          $path = $stylesheet_directory;
4732      } elseif ( $stylesheet_directory !== $template_directory && file_exists( $stylesheet_directory . '/' . $file ) ) {
4733          $path = $stylesheet_directory . '/' . $file;
4734      } else {
4735          $path = $template_directory . '/' . $file;
4736      }
4737  
4738      /**
4739       * Filters the path to a file in the theme.
4740       *
4741       * @since 4.7.0
4742       *
4743       * @param string $path The file path.
4744       * @param string $file The requested file to search for.
4745       */
4746      return apply_filters( 'theme_file_path', $path, $file );
4747  }
4748  
4749  /**
4750   * Retrieves the path of a file in the parent theme.
4751   *
4752   * @since 4.7.0
4753   *
4754   * @param string $file Optional. File to return the path for in the template directory.
4755   * @return string The path of the file.
4756   */
4757  function get_parent_theme_file_path( $file = '' ) {
4758      $file = ltrim( $file, '/' );
4759  
4760      if ( empty( $file ) ) {
4761          $path = get_template_directory();
4762      } else {
4763          $path = get_template_directory() . '/' . $file;
4764      }
4765  
4766      /**
4767       * Filters the path to a file in the parent theme.
4768       *
4769       * @since 4.7.0
4770       *
4771       * @param string $path The file path.
4772       * @param string $file The requested file to search for.
4773       */
4774      return apply_filters( 'parent_theme_file_path', $path, $file );
4775  }
4776  
4777  /**
4778   * Retrieves the URL to the privacy policy page.
4779   *
4780   * @since 4.9.6
4781   *
4782   * @return string The URL to the privacy policy page. Empty string if it doesn't exist.
4783   */
4784  function get_privacy_policy_url() {
4785      $url            = '';
4786      $policy_page_id = (int) get_option( 'wp_page_for_privacy_policy' );
4787  
4788      if ( ! empty( $policy_page_id ) && get_post_status( $policy_page_id ) === 'publish' ) {
4789          $url = (string) get_permalink( $policy_page_id );
4790      }
4791  
4792      /**
4793       * Filters the URL of the privacy policy page.
4794       *
4795       * @since 4.9.6
4796       *
4797       * @param string $url            The URL to the privacy policy page. Empty string
4798       *                               if it doesn't exist.
4799       * @param int    $policy_page_id The ID of privacy policy page.
4800       */
4801      return apply_filters( 'privacy_policy_url', $url, $policy_page_id );
4802  }
4803  
4804  /**
4805   * Displays the privacy policy link with formatting, when applicable.
4806   *
4807   * @since 4.9.6
4808   *
4809   * @param string $before Optional. Display before privacy policy link. Default empty.
4810   * @param string $after  Optional. Display after privacy policy link. Default empty.
4811   */
4812  function the_privacy_policy_link( $before = '', $after = '' ) {
4813      echo get_the_privacy_policy_link( $before, $after );
4814  }
4815  
4816  /**
4817   * Returns the privacy policy link with formatting, when applicable.
4818   *
4819   * @since 4.9.6
4820   * @since 6.2.0 Added 'privacy-policy' rel attribute.
4821   *
4822   * @param string $before Optional. Display before privacy policy link. Default empty.
4823   * @param string $after  Optional. Display after privacy policy link. Default empty.
4824   * @return string Markup for the link and surrounding elements. Empty string if it
4825   *                doesn't exist.
4826   */
4827  function get_the_privacy_policy_link( $before = '', $after = '' ) {
4828      $link               = '';
4829      $privacy_policy_url = get_privacy_policy_url();
4830      $policy_page_id     = (int) get_option( 'wp_page_for_privacy_policy' );
4831      $page_title         = ( $policy_page_id ) ? get_the_title( $policy_page_id ) : '';
4832  
4833      if ( $privacy_policy_url && $page_title ) {
4834          $link = sprintf(
4835              '<a class="privacy-policy-link" href="%s" rel="privacy-policy">%s</a>',
4836              esc_url( $privacy_policy_url ),
4837              esc_html( $page_title )
4838          );
4839      }
4840  
4841      /**
4842       * Filters the privacy policy link.
4843       *
4844       * @since 4.9.6
4845       *
4846       * @param string $link               The privacy policy link. Empty string if it
4847       *                                   doesn't exist.
4848       * @param string $privacy_policy_url The URL of the privacy policy. Empty string
4849       *                                   if it doesn't exist.
4850       */
4851      $link = apply_filters( 'the_privacy_policy_link', $link, $privacy_policy_url );
4852  
4853      if ( $link ) {
4854          return $before . $link . $after;
4855      }
4856  
4857      return '';
4858  }
4859  
4860  /**
4861   * Returns an array of URL hosts which are considered to be internal hosts.
4862   *
4863   * By default the list of internal hosts is comprised of the host name of
4864   * the site's home_url() (as parsed by wp_parse_url()).
4865   *
4866   * This list is used when determining if a specified URL is a link to a page on
4867   * the site itself or a link offsite (to an external host). This is used, for
4868   * example, when determining if the "nofollow" attribute should be applied to a
4869   * link.
4870   *
4871   * @see wp_is_internal_link
4872   *
4873   * @since 6.2.0
4874   *
4875   * @return string[] An array of URL hosts.
4876   */
4877  function wp_internal_hosts() {
4878      static $internal_hosts;
4879  
4880      if ( empty( $internal_hosts ) ) {
4881          /**
4882           * Filters the array of URL hosts which are considered internal.
4883           *
4884           * @since 6.2.0
4885           *
4886           * @param string[] $internal_hosts An array of internal URL hostnames.
4887           */
4888          $internal_hosts = apply_filters(
4889              'wp_internal_hosts',
4890              array(
4891                  wp_parse_url( home_url(), PHP_URL_HOST ),
4892              )
4893          );
4894          $internal_hosts = array_unique(
4895              array_map( 'strtolower', (array) $internal_hosts )
4896          );
4897      }
4898  
4899      return $internal_hosts;
4900  }
4901  
4902  /**
4903   * Determines whether or not the specified URL is of a host included in the internal hosts list.
4904   *
4905   * @see wp_internal_hosts()
4906   *
4907   * @since 6.2.0
4908   *
4909   * @param string $link The URL to test.
4910   * @return bool Returns true for internal URLs and false for all other URLs.
4911   */
4912  function wp_is_internal_link( $link ) {
4913      $link = strtolower( $link );
4914      if ( in_array( wp_parse_url( $link, PHP_URL_SCHEME ), wp_allowed_protocols(), true ) ) {
4915          return in_array( wp_parse_url( $link, PHP_URL_HOST ), wp_internal_hosts(), true );
4916      }
4917      return false;
4918  }


Generated : Tue Sep 1 08:20:25 2026 Cross-referenced by PHPXref