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/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 WP_Post|int|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 = null !== $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 = false, $leavename = false, $sample = false ) {
 392      $post = get_post( $post );
 393  
 394      if ( 'page' === get_option( 'show_on_front' ) && 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 = false, $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|object $post      Optional. Post ID or object. Default uses the global `$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' ) && 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 = '', $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;
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;
1092      }
1093  
1094      $args = array(
1095          'taxonomy' => $taxonomy,
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|void 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;
1145      }
1146  
1147      $tax = get_taxonomy( $term->taxonomy );
1148      if ( ! current_user_can( 'edit_term', $term->term_id ) ) {
1149          return;
1150      }
1151  
1152      if ( empty( $link ) ) {
1153          $link = __( 'Edit This' );
1154      }
1155  
1156      $link = '<a href="' . get_edit_term_link( $term->term_id, $term->taxonomy ) . '">' . $link . '</a>';
1157  
1158      /**
1159       * Filters the anchor tag for the edit link of a term.
1160       *
1161       * @since 3.1.0
1162       *
1163       * @param string $link    The anchor tag for the edit link.
1164       * @param int    $term_id Term ID.
1165       */
1166      $link = $before . apply_filters( 'edit_term_link', $link, $term->term_id ) . $after;
1167  
1168      if ( $display ) {
1169          echo $link;
1170      } else {
1171          return $link;
1172      }
1173  }
1174  
1175  /**
1176   * Retrieves the permalink for a search.
1177   *
1178   * @since 3.0.0
1179   *
1180   * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
1181   *
1182   * @param string $query Optional. The query string to use. If empty the current query is used. Default empty.
1183   * @return string The search permalink.
1184   */
1185  function get_search_link( $query = '' ) {
1186      global $wp_rewrite;
1187  
1188      if ( empty( $query ) ) {
1189          $search = get_search_query( false );
1190      } else {
1191          $search = stripslashes( $query );
1192      }
1193  
1194      $permastruct = $wp_rewrite->get_search_permastruct();
1195  
1196      if ( empty( $permastruct ) ) {
1197          $link = home_url( '?s=' . urlencode( $search ) );
1198      } else {
1199          $search = urlencode( $search );
1200          $search = str_replace( '%2F', '/', $search ); // %2F(/) is not valid within a URL, send it un-encoded.
1201          $link   = str_replace( '%search%', $search, $permastruct );
1202          $link   = home_url( user_trailingslashit( $link, 'search' ) );
1203      }
1204  
1205      /**
1206       * Filters the search permalink.
1207       *
1208       * @since 3.0.0
1209       *
1210       * @param string $link   Search permalink.
1211       * @param string $search The URL-encoded search term.
1212       */
1213      return apply_filters( 'search_link', $link, $search );
1214  }
1215  
1216  /**
1217   * Retrieves the permalink for the search results feed.
1218   *
1219   * @since 2.5.0
1220   *
1221   * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
1222   *
1223   * @param string $search_query Optional. Search query. Default empty.
1224   * @param string $feed         Optional. Feed type. Possible values include 'rss2', 'atom'.
1225   *                             Default is the value of get_default_feed().
1226   * @return string The search results feed permalink.
1227   */
1228  function get_search_feed_link( $search_query = '', $feed = '' ) {
1229      global $wp_rewrite;
1230      $link = get_search_link( $search_query );
1231  
1232      if ( empty( $feed ) ) {
1233          $feed = get_default_feed();
1234      }
1235  
1236      $permastruct = $wp_rewrite->get_search_permastruct();
1237  
1238      if ( empty( $permastruct ) ) {
1239          $link = add_query_arg( 'feed', $feed, $link );
1240      } else {
1241          $link  = trailingslashit( $link );
1242          $link .= "feed/$feed/";
1243      }
1244  
1245      /**
1246       * Filters the search feed link.
1247       *
1248       * @since 2.5.0
1249       *
1250       * @param string $link Search feed link.
1251       * @param string $feed Feed type. Possible values include 'rss2', 'atom'.
1252       * @param string $type The search type. One of 'posts' or 'comments'.
1253       */
1254      return apply_filters( 'search_feed_link', $link, $feed, 'posts' );
1255  }
1256  
1257  /**
1258   * Retrieves the permalink for the search results comments feed.
1259   *
1260   * @since 2.5.0
1261   *
1262   * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
1263   *
1264   * @param string $search_query Optional. Search query. Default empty.
1265   * @param string $feed         Optional. Feed type. Possible values include 'rss2', 'atom'.
1266   *                             Default is the value of get_default_feed().
1267   * @return string The comments feed search results permalink.
1268   */
1269  function get_search_comments_feed_link( $search_query = '', $feed = '' ) {
1270      global $wp_rewrite;
1271  
1272      if ( empty( $feed ) ) {
1273          $feed = get_default_feed();
1274      }
1275  
1276      $link = get_search_feed_link( $search_query, $feed );
1277  
1278      $permastruct = $wp_rewrite->get_search_permastruct();
1279  
1280      if ( empty( $permastruct ) ) {
1281          $link = add_query_arg( 'feed', 'comments-' . $feed, $link );
1282      } else {
1283          $link = add_query_arg( 'withcomments', 1, $link );
1284      }
1285  
1286      /** This filter is documented in wp-includes/link-template.php */
1287      return apply_filters( 'search_feed_link', $link, $feed, 'comments' );
1288  }
1289  
1290  /**
1291   * Retrieves the permalink for a post type archive.
1292   *
1293   * @since 3.1.0
1294   * @since 4.5.0 Support for posts was added.
1295   *
1296   * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
1297   *
1298   * @param string $post_type Post type.
1299   * @return string|false The post type archive permalink. False if the post type
1300   *                      does not exist or does not have an archive.
1301   */
1302  function get_post_type_archive_link( $post_type ) {
1303      global $wp_rewrite;
1304  
1305      $post_type_obj = get_post_type_object( $post_type );
1306  
1307      if ( ! $post_type_obj ) {
1308          return false;
1309      }
1310  
1311      if ( 'post' === $post_type ) {
1312          $show_on_front  = get_option( 'show_on_front' );
1313          $page_for_posts = get_option( 'page_for_posts' );
1314  
1315          if ( 'page' === $show_on_front && $page_for_posts ) {
1316              $link = get_permalink( $page_for_posts );
1317          } else {
1318              $link = get_home_url();
1319          }
1320          /** This filter is documented in wp-includes/link-template.php */
1321          return apply_filters( 'post_type_archive_link', $link, $post_type );
1322      }
1323  
1324      if ( ! $post_type_obj->has_archive ) {
1325          return false;
1326      }
1327  
1328      if ( get_option( 'permalink_structure' ) && is_array( $post_type_obj->rewrite ) ) {
1329          $struct = ( true === $post_type_obj->has_archive ) ? $post_type_obj->rewrite['slug'] : $post_type_obj->has_archive;
1330          if ( $post_type_obj->rewrite['with_front'] ) {
1331              $struct = $wp_rewrite->front . $struct;
1332          } else {
1333              $struct = $wp_rewrite->root . $struct;
1334          }
1335          $link = home_url( user_trailingslashit( $struct, 'post_type_archive' ) );
1336      } else {
1337          $link = home_url( '?post_type=' . $post_type );
1338      }
1339  
1340      /**
1341       * Filters the post type archive permalink.
1342       *
1343       * @since 3.1.0
1344       *
1345       * @param string $link      The post type archive permalink.
1346       * @param string $post_type Post type name.
1347       */
1348      return apply_filters( 'post_type_archive_link', $link, $post_type );
1349  }
1350  
1351  /**
1352   * Retrieves the permalink for a post type archive feed.
1353   *
1354   * @since 3.1.0
1355   *
1356   * @param string $post_type Post type.
1357   * @param string $feed      Optional. Feed type. Possible values include 'rss2', 'atom'.
1358   *                          Default is the value of get_default_feed().
1359   * @return string|false The post type feed permalink. False if the post type
1360   *                      does not exist or does not have an archive.
1361   */
1362  function get_post_type_archive_feed_link( $post_type, $feed = '' ) {
1363      $default_feed = get_default_feed();
1364      if ( empty( $feed ) ) {
1365          $feed = $default_feed;
1366      }
1367  
1368      $link = get_post_type_archive_link( $post_type );
1369      if ( ! $link ) {
1370          return false;
1371      }
1372  
1373      $post_type_obj = get_post_type_object( $post_type );
1374      if ( get_option( 'permalink_structure' ) && is_array( $post_type_obj->rewrite ) && $post_type_obj->rewrite['feeds'] ) {
1375          $link  = trailingslashit( $link );
1376          $link .= 'feed/';
1377          if ( $feed != $default_feed ) {
1378              $link .= "$feed/";
1379          }
1380      } else {
1381          $link = add_query_arg( 'feed', $feed, $link );
1382      }
1383  
1384      /**
1385       * Filters the post type archive feed link.
1386       *
1387       * @since 3.1.0
1388       *
1389       * @param string $link The post type archive feed link.
1390       * @param string $feed Feed type. Possible values include 'rss2', 'atom'.
1391       */
1392      return apply_filters( 'post_type_archive_feed_link', $link, $feed );
1393  }
1394  
1395  /**
1396   * Retrieves the URL used for the post preview.
1397   *
1398   * Allows additional query args to be appended.
1399   *
1400   * @since 4.4.0
1401   *
1402   * @param int|WP_Post $post         Optional. Post ID or `WP_Post` object. Defaults to global `$post`.
1403   * @param array       $query_args   Optional. Array of additional query args to be appended to the link.
1404   *                                  Default empty array.
1405   * @param string      $preview_link Optional. Base preview link to be used if it should differ from the
1406   *                                  post permalink. Default empty.
1407   * @return string|null URL used for the post preview, or null if the post does not exist.
1408   */
1409  function get_preview_post_link( $post = null, $query_args = array(), $preview_link = '' ) {
1410      $post = get_post( $post );
1411  
1412      if ( ! $post ) {
1413          return;
1414      }
1415  
1416      $post_type_object = get_post_type_object( $post->post_type );
1417      if ( is_post_type_viewable( $post_type_object ) ) {
1418          if ( ! $preview_link ) {
1419              $preview_link = set_url_scheme( get_permalink( $post ) );
1420          }
1421  
1422          $query_args['preview'] = 'true';
1423          $preview_link          = add_query_arg( $query_args, $preview_link );
1424      }
1425  
1426      /**
1427       * Filters the URL used for a post preview.
1428       *
1429       * @since 2.0.5
1430       * @since 4.0.0 Added the `$post` parameter.
1431       *
1432       * @param string  $preview_link URL used for the post preview.
1433       * @param WP_Post $post         Post object.
1434       */
1435      return apply_filters( 'preview_post_link', $preview_link, $post );
1436  }
1437  
1438  /**
1439   * Retrieves the edit post link for post.
1440   *
1441   * Can be used within the WordPress loop or outside of it. Can be used with
1442   * pages, posts, attachments, revisions, global styles, templates, and template parts.
1443   *
1444   * @since 2.3.0
1445   * @since 6.3.0 Adds custom link for wp_navigation post types.
1446   *              Adds custom links for wp_template_part and wp_template post types.
1447   *
1448   * @param int|WP_Post $post    Optional. Post ID or post object. Default is the global `$post`.
1449   * @param string      $context Optional. How to output the '&' character. Default '&amp;'.
1450   * @return string|null The edit post link for the given post. Null if the post type does not exist
1451   *                     or does not allow an editing UI.
1452   */
1453  function get_edit_post_link( $post = 0, $context = 'display' ) {
1454      $post = get_post( $post );
1455  
1456      if ( ! $post ) {
1457          return;
1458      }
1459  
1460      if ( 'revision' === $post->post_type ) {
1461          $action = '';
1462      } elseif ( 'display' === $context ) {
1463          $action = '&amp;action=edit';
1464      } else {
1465          $action = '&action=edit';
1466      }
1467  
1468      $post_type_object = get_post_type_object( $post->post_type );
1469  
1470      if ( ! $post_type_object ) {
1471          return;
1472      }
1473  
1474      if ( ! current_user_can( 'edit_post', $post->ID ) ) {
1475          return;
1476      }
1477  
1478      $link = '';
1479  
1480      if ( 'wp_template' === $post->post_type || 'wp_template_part' === $post->post_type ) {
1481          $slug = urlencode( get_stylesheet() . '//' . $post->post_name );
1482          $link = admin_url( sprintf( $post_type_object->_edit_link, $post->post_type, $slug ) );
1483      } elseif ( 'wp_navigation' === $post->post_type ) {
1484          $link = admin_url( sprintf( $post_type_object->_edit_link, (string) $post->ID ) );
1485      } elseif ( $post_type_object->_edit_link ) {
1486          $link = admin_url( sprintf( $post_type_object->_edit_link . $action, $post->ID ) );
1487      }
1488  
1489      /**
1490       * Filters the post edit link.
1491       *
1492       * @since 2.3.0
1493       *
1494       * @param string $link    The edit link.
1495       * @param int    $post_id Post ID.
1496       * @param string $context The link context. If set to 'display' then ampersands
1497       *                        are encoded.
1498       */
1499      return apply_filters( 'get_edit_post_link', $link, $post->ID, $context );
1500  }
1501  
1502  /**
1503   * Displays the edit post link for post.
1504   *
1505   * @since 1.0.0
1506   * @since 4.4.0 The `$css_class` argument was added.
1507   *
1508   * @param string      $text      Optional. Anchor text. If null, default is 'Edit This'. Default null.
1509   * @param string      $before    Optional. Display before edit link. Default empty.
1510   * @param string      $after     Optional. Display after edit link. Default empty.
1511   * @param int|WP_Post $post      Optional. Post ID or post object. Default is the global `$post`.
1512   * @param string      $css_class Optional. Add custom class to link. Default 'post-edit-link'.
1513   */
1514  function edit_post_link( $text = null, $before = '', $after = '', $post = 0, $css_class = 'post-edit-link' ) {
1515      $post = get_post( $post );
1516  
1517      if ( ! $post ) {
1518          return;
1519      }
1520  
1521      $url = get_edit_post_link( $post->ID );
1522  
1523      if ( ! $url ) {
1524          return;
1525      }
1526  
1527      if ( null === $text ) {
1528          $text = __( 'Edit This' );
1529      }
1530  
1531      $link = '<a class="' . esc_attr( $css_class ) . '" href="' . esc_url( $url ) . '">' . $text . '</a>';
1532  
1533      /**
1534       * Filters the post edit link anchor tag.
1535       *
1536       * @since 2.3.0
1537       *
1538       * @param string $link    Anchor tag for the edit link.
1539       * @param int    $post_id Post ID.
1540       * @param string $text    Anchor text.
1541       */
1542      echo $before . apply_filters( 'edit_post_link', $link, $post->ID, $text ) . $after;
1543  }
1544  
1545  /**
1546   * Retrieves the delete posts link for post.
1547   *
1548   * Can be used within the WordPress loop or outside of it, with any post type.
1549   *
1550   * @since 2.9.0
1551   *
1552   * @param int|WP_Post $post         Optional. Post ID or post object. Default is the global `$post`.
1553   * @param string      $deprecated   Not used.
1554   * @param bool        $force_delete Optional. Whether to bypass Trash and force deletion. Default false.
1555   * @return string|void The delete post link URL for the given post.
1556   */
1557  function get_delete_post_link( $post = 0, $deprecated = '', $force_delete = false ) {
1558      if ( ! empty( $deprecated ) ) {
1559          _deprecated_argument( __FUNCTION__, '3.0.0' );
1560      }
1561  
1562      $post = get_post( $post );
1563  
1564      if ( ! $post ) {
1565          return;
1566      }
1567  
1568      $post_type_object = get_post_type_object( $post->post_type );
1569  
1570      if ( ! $post_type_object ) {
1571          return;
1572      }
1573  
1574      if ( ! current_user_can( 'delete_post', $post->ID ) ) {
1575          return;
1576      }
1577  
1578      $action = ( $force_delete || ! EMPTY_TRASH_DAYS ) ? 'delete' : 'trash';
1579  
1580      $delete_link = add_query_arg( 'action', $action, admin_url( sprintf( $post_type_object->_edit_link, $post->ID ) ) );
1581  
1582      /**
1583       * Filters the post delete link.
1584       *
1585       * @since 2.9.0
1586       *
1587       * @param string $link         The delete link.
1588       * @param int    $post_id      Post ID.
1589       * @param bool   $force_delete Whether to bypass the Trash and force deletion. Default false.
1590       */
1591      return apply_filters( 'get_delete_post_link', wp_nonce_url( $delete_link, "$action-post_{$post->ID}" ), $post->ID, $force_delete );
1592  }
1593  
1594  /**
1595   * Retrieves the edit comment link.
1596   *
1597   * @since 2.3.0
1598   *
1599   * @param int|WP_Comment $comment_id Optional. Comment ID or WP_Comment object.
1600   * @return string|void The edit comment link URL for the given comment.
1601   */
1602  function get_edit_comment_link( $comment_id = 0 ) {
1603      $comment = get_comment( $comment_id );
1604  
1605      if ( ! current_user_can( 'edit_comment', $comment->comment_ID ) ) {
1606          return;
1607      }
1608  
1609      $location = admin_url( 'comment.php?action=editcomment&amp;c=' ) . $comment->comment_ID;
1610  
1611      /**
1612       * Filters the comment edit link.
1613       *
1614       * @since 2.3.0
1615       *
1616       * @param string $location The edit link.
1617       */
1618      return apply_filters( 'get_edit_comment_link', $location );
1619  }
1620  
1621  /**
1622   * Displays the edit comment link with formatting.
1623   *
1624   * @since 1.0.0
1625   *
1626   * @param string $text   Optional. Anchor text. If null, default is 'Edit This'. Default null.
1627   * @param string $before Optional. Display before edit link. Default empty.
1628   * @param string $after  Optional. Display after edit link. Default empty.
1629   */
1630  function edit_comment_link( $text = null, $before = '', $after = '' ) {
1631      $comment = get_comment();
1632  
1633      if ( ! current_user_can( 'edit_comment', $comment->comment_ID ) ) {
1634          return;
1635      }
1636  
1637      if ( null === $text ) {
1638          $text = __( 'Edit This' );
1639      }
1640  
1641      $link = '<a class="comment-edit-link" href="' . esc_url( get_edit_comment_link( $comment ) ) . '">' . $text . '</a>';
1642  
1643      /**
1644       * Filters the comment edit link anchor tag.
1645       *
1646       * @since 2.3.0
1647       *
1648       * @param string $link       Anchor tag for the edit link.
1649       * @param string $comment_id Comment ID as a numeric string.
1650       * @param string $text       Anchor text.
1651       */
1652      echo $before . apply_filters( 'edit_comment_link', $link, $comment->comment_ID, $text ) . $after;
1653  }
1654  
1655  /**
1656   * Displays the edit bookmark link.
1657   *
1658   * @since 2.7.0
1659   *
1660   * @param int|stdClass $link Optional. Bookmark ID. Default is the ID of the current bookmark.
1661   * @return string|void The edit bookmark link URL.
1662   */
1663  function get_edit_bookmark_link( $link = 0 ) {
1664      $link = get_bookmark( $link );
1665  
1666      if ( ! current_user_can( 'manage_links' ) ) {
1667          return;
1668      }
1669  
1670      $location = admin_url( 'link.php?action=edit&amp;link_id=' ) . $link->link_id;
1671  
1672      /**
1673       * Filters the bookmark edit link.
1674       *
1675       * @since 2.7.0
1676       *
1677       * @param string $location The edit link.
1678       * @param int    $link_id  Bookmark ID.
1679       */
1680      return apply_filters( 'get_edit_bookmark_link', $location, $link->link_id );
1681  }
1682  
1683  /**
1684   * Displays the edit bookmark link anchor content.
1685   *
1686   * @since 2.7.0
1687   *
1688   * @param string $link     Optional. Anchor text. If empty, default is 'Edit This'. Default empty.
1689   * @param string $before   Optional. Display before edit link. Default empty.
1690   * @param string $after    Optional. Display after edit link. Default empty.
1691   * @param int    $bookmark Optional. Bookmark ID. Default is the current bookmark.
1692   */
1693  function edit_bookmark_link( $link = '', $before = '', $after = '', $bookmark = null ) {
1694      $bookmark = get_bookmark( $bookmark );
1695  
1696      if ( ! current_user_can( 'manage_links' ) ) {
1697          return;
1698      }
1699  
1700      if ( empty( $link ) ) {
1701          $link = __( 'Edit This' );
1702      }
1703  
1704      $link = '<a href="' . esc_url( get_edit_bookmark_link( $bookmark ) ) . '">' . $link . '</a>';
1705  
1706      /**
1707       * Filters the bookmark edit link anchor tag.
1708       *
1709       * @since 2.7.0
1710       *
1711       * @param string $link    Anchor tag for the edit link.
1712       * @param int    $link_id Bookmark ID.
1713       */
1714      echo $before . apply_filters( 'edit_bookmark_link', $link, $bookmark->link_id ) . $after;
1715  }
1716  
1717  /**
1718   * Retrieves the edit user link.
1719   *
1720   * @since 3.5.0
1721   *
1722   * @param int $user_id Optional. User ID. Defaults to the current user.
1723   * @return string URL to edit user page or empty string.
1724   */
1725  function get_edit_user_link( $user_id = null ) {
1726      if ( ! $user_id ) {
1727          $user_id = get_current_user_id();
1728      }
1729  
1730      if ( empty( $user_id ) || ! current_user_can( 'edit_user', $user_id ) ) {
1731          return '';
1732      }
1733  
1734      $user = get_userdata( $user_id );
1735  
1736      if ( ! $user ) {
1737          return '';
1738      }
1739  
1740      if ( get_current_user_id() == $user->ID ) {
1741          $link = get_edit_profile_url( $user->ID );
1742      } else {
1743          $link = add_query_arg( 'user_id', $user->ID, self_admin_url( 'user-edit.php' ) );
1744      }
1745  
1746      /**
1747       * Filters the user edit link.
1748       *
1749       * @since 3.5.0
1750       *
1751       * @param string $link    The edit link.
1752       * @param int    $user_id User ID.
1753       */
1754      return apply_filters( 'get_edit_user_link', $link, $user->ID );
1755  }
1756  
1757  //
1758  // Navigation links.
1759  //
1760  
1761  /**
1762   * Retrieves the previous post that is adjacent to the current post.
1763   *
1764   * @since 1.5.0
1765   *
1766   * @param bool         $in_same_term   Optional. Whether post should be in the same taxonomy term.
1767   *                                     Default false.
1768   * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs.
1769   *                                     Default empty.
1770   * @param string       $taxonomy       Optional. Taxonomy, if `$in_same_term` is true. Default 'category'.
1771   * @return WP_Post|null|string Post object if successful. Null if global `$post` is not set.
1772   *                             Empty string if no corresponding post exists.
1773   */
1774  function get_previous_post( $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
1775      return get_adjacent_post( $in_same_term, $excluded_terms, true, $taxonomy );
1776  }
1777  
1778  /**
1779   * Retrieves the next 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_next_post( $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
1792      return get_adjacent_post( $in_same_term, $excluded_terms, false, $taxonomy );
1793  }
1794  
1795  /**
1796   * Retrieves the adjacent post.
1797   *
1798   * Can either be next or previous post.
1799   *
1800   * @since 2.5.0
1801   *
1802   * @global wpdb $wpdb WordPress database abstraction object.
1803   *
1804   * @param bool         $in_same_term   Optional. Whether post should be in the same taxonomy term.
1805   *                                     Default false.
1806   * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs.
1807   *                                     Default empty string.
1808   * @param bool         $previous       Optional. Whether to retrieve previous post.
1809   *                                     Default true.
1810   * @param string       $taxonomy       Optional. Taxonomy, if `$in_same_term` is true. Default 'category'.
1811   * @return WP_Post|null|string Post object if successful. Null if global `$post` is not set.
1812   *                             Empty string if no corresponding post exists.
1813   */
1814  function get_adjacent_post( $in_same_term = false, $excluded_terms = '', $previous = true, $taxonomy = 'category' ) {
1815      global $wpdb;
1816  
1817      $post = get_post();
1818  
1819      if ( ! $post || ! taxonomy_exists( $taxonomy ) ) {
1820          return null;
1821      }
1822  
1823      $current_post_date = $post->post_date;
1824  
1825      $join     = '';
1826      $where    = '';
1827      $adjacent = $previous ? 'previous' : 'next';
1828  
1829      if ( ! empty( $excluded_terms ) && ! is_array( $excluded_terms ) ) {
1830          // Back-compat, $excluded_terms used to be $excluded_categories with IDs separated by " and ".
1831          if ( str_contains( $excluded_terms, ' and ' ) ) {
1832              _deprecated_argument(
1833                  __FUNCTION__,
1834                  '3.3.0',
1835                  sprintf(
1836                      /* translators: %s: The word 'and'. */
1837                      __( 'Use commas instead of %s to separate excluded terms.' ),
1838                      "'and'"
1839                  )
1840              );
1841              $excluded_terms = explode( ' and ', $excluded_terms );
1842          } else {
1843              $excluded_terms = explode( ',', $excluded_terms );
1844          }
1845  
1846          $excluded_terms = array_map( 'intval', $excluded_terms );
1847      }
1848  
1849      /**
1850       * Filters the IDs of terms excluded from adjacent post queries.
1851       *
1852       * The dynamic portion of the hook name, `$adjacent`, refers to the type
1853       * of adjacency, 'next' or 'previous'.
1854       *
1855       * Possible hook names include:
1856       *
1857       *  - `get_next_post_excluded_terms`
1858       *  - `get_previous_post_excluded_terms`
1859       *
1860       * @since 4.4.0
1861       *
1862       * @param int[]|string $excluded_terms Array of excluded term IDs. Empty string if none were provided.
1863       */
1864      $excluded_terms = apply_filters( "get_{$adjacent}_post_excluded_terms", $excluded_terms );
1865  
1866      if ( $in_same_term || ! empty( $excluded_terms ) ) {
1867          if ( $in_same_term ) {
1868              $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";
1869              $where .= $wpdb->prepare( 'AND tt.taxonomy = %s', $taxonomy );
1870  
1871              if ( ! is_object_in_taxonomy( $post->post_type, $taxonomy ) ) {
1872                  return '';
1873              }
1874              $term_array = wp_get_object_terms( $post->ID, $taxonomy, array( 'fields' => 'ids' ) );
1875  
1876              // Remove any exclusions from the term array to include.
1877              $term_array = array_diff( $term_array, (array) $excluded_terms );
1878              $term_array = array_map( 'intval', $term_array );
1879  
1880              if ( ! $term_array || is_wp_error( $term_array ) ) {
1881                  return '';
1882              }
1883  
1884              $where .= ' AND tt.term_id IN (' . implode( ',', $term_array ) . ')';
1885          }
1886  
1887          if ( ! empty( $excluded_terms ) ) {
1888              $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 ) ) . ') )';
1889          }
1890      }
1891  
1892      // 'post_status' clause depends on the current user.
1893      if ( is_user_logged_in() ) {
1894          $user_id = get_current_user_id();
1895  
1896          $post_type_object = get_post_type_object( $post->post_type );
1897          if ( empty( $post_type_object ) ) {
1898              $post_type_cap    = $post->post_type;
1899              $read_private_cap = 'read_private_' . $post_type_cap . 's';
1900          } else {
1901              $read_private_cap = $post_type_object->cap->read_private_posts;
1902          }
1903  
1904          /*
1905           * Results should include private posts belonging to the current user, or private posts where the
1906           * current user has the 'read_private_posts' cap.
1907           */
1908          $private_states = get_post_stati( array( 'private' => true ) );
1909          $where         .= " AND ( p.post_status = 'publish'";
1910          foreach ( $private_states as $state ) {
1911              if ( current_user_can( $read_private_cap ) ) {
1912                  $where .= $wpdb->prepare( ' OR p.post_status = %s', $state );
1913              } else {
1914                  $where .= $wpdb->prepare( ' OR (p.post_author = %d AND p.post_status = %s)', $user_id, $state );
1915              }
1916          }
1917          $where .= ' )';
1918      } else {
1919          $where .= " AND p.post_status = 'publish'";
1920      }
1921  
1922      $op    = $previous ? '<' : '>';
1923      $order = $previous ? 'DESC' : 'ASC';
1924  
1925      /**
1926       * Filters the JOIN clause in the SQL for an adjacent post query.
1927       *
1928       * The dynamic portion of the hook name, `$adjacent`, refers to the type
1929       * of adjacency, 'next' or 'previous'.
1930       *
1931       * Possible hook names include:
1932       *
1933       *  - `get_next_post_join`
1934       *  - `get_previous_post_join`
1935       *
1936       * @since 2.5.0
1937       * @since 4.4.0 Added the `$taxonomy` and `$post` parameters.
1938       *
1939       * @param string       $join           The JOIN clause in the SQL.
1940       * @param bool         $in_same_term   Whether post should be in the same taxonomy term.
1941       * @param int[]|string $excluded_terms Array of excluded term IDs. Empty string if none were provided.
1942       * @param string       $taxonomy       Taxonomy. Used to identify the term used when `$in_same_term` is true.
1943       * @param WP_Post      $post           WP_Post object.
1944       */
1945      $join = apply_filters( "get_{$adjacent}_post_join", $join, $in_same_term, $excluded_terms, $taxonomy, $post );
1946  
1947      /**
1948       * Filters the WHERE clause in the SQL for an adjacent post query.
1949       *
1950       * The dynamic portion of the hook name, `$adjacent`, refers to the type
1951       * of adjacency, 'next' or 'previous'.
1952       *
1953       * Possible hook names include:
1954       *
1955       *  - `get_next_post_where`
1956       *  - `get_previous_post_where`
1957       *
1958       * @since 2.5.0
1959       * @since 4.4.0 Added the `$taxonomy` and `$post` parameters.
1960       *
1961       * @param string       $where          The `WHERE` clause in the SQL.
1962       * @param bool         $in_same_term   Whether post should be in the same taxonomy term.
1963       * @param int[]|string $excluded_terms Array of excluded term IDs. Empty string if none were provided.
1964       * @param string       $taxonomy       Taxonomy. Used to identify the term used when `$in_same_term` is true.
1965       * @param WP_Post      $post           WP_Post object.
1966       */
1967      $where = apply_filters( "get_{$adjacent}_post_where", $wpdb->prepare( "WHERE p.post_date $op %s AND p.post_type = %s $where", $current_post_date, $post->post_type ), $in_same_term, $excluded_terms, $taxonomy, $post );
1968  
1969      /**
1970       * Filters the ORDER BY clause in the SQL for an adjacent post query.
1971       *
1972       * The dynamic portion of the hook name, `$adjacent`, refers to the type
1973       * of adjacency, 'next' or 'previous'.
1974       *
1975       * Possible hook names include:
1976       *
1977       *  - `get_next_post_sort`
1978       *  - `get_previous_post_sort`
1979       *
1980       * @since 2.5.0
1981       * @since 4.4.0 Added the `$post` parameter.
1982       * @since 4.9.0 Added the `$order` parameter.
1983       *
1984       * @param string $order_by The `ORDER BY` clause in the SQL.
1985       * @param WP_Post $post    WP_Post object.
1986       * @param string  $order   Sort order. 'DESC' for previous post, 'ASC' for next.
1987       */
1988      $sort = apply_filters( "get_{$adjacent}_post_sort", "ORDER BY p.post_date $order LIMIT 1", $post, $order );
1989  
1990      $query        = "SELECT p.ID FROM $wpdb->posts AS p $join $where $sort";
1991      $key          = md5( $query );
1992      $last_changed = wp_cache_get_last_changed( 'posts' );
1993      if ( $in_same_term || ! empty( $excluded_terms ) ) {
1994          $last_changed .= wp_cache_get_last_changed( 'terms' );
1995      }
1996      $cache_key = "adjacent_post:$key:$last_changed";
1997  
1998      $result = wp_cache_get( $cache_key, 'post-queries' );
1999      if ( false !== $result ) {
2000          if ( $result ) {
2001              $result = get_post( $result );
2002          }
2003          return $result;
2004      }
2005  
2006      $result = $wpdb->get_var( $query );
2007      if ( null === $result ) {
2008          $result = '';
2009      }
2010  
2011      wp_cache_set( $cache_key, $result, 'post-queries' );
2012  
2013      if ( $result ) {
2014          $result = get_post( $result );
2015      }
2016  
2017      return $result;
2018  }
2019  
2020  /**
2021   * Retrieves the adjacent post relational link.
2022   *
2023   * Can either be next or previous post relational link.
2024   *
2025   * @since 2.8.0
2026   *
2027   * @param string       $title          Optional. Link title format. Default '%title'.
2028   * @param bool         $in_same_term   Optional. Whether link should be in the same taxonomy term.
2029   *                                     Default false.
2030   * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs.
2031   *                                     Default empty.
2032   * @param bool         $previous       Optional. Whether to display link to previous or next post.
2033   *                                     Default true.
2034   * @param string       $taxonomy       Optional. Taxonomy, if `$in_same_term` is true. Default 'category'.
2035   * @return string|void The adjacent post relational link URL.
2036   */
2037  function get_adjacent_post_rel_link( $title = '%title', $in_same_term = false, $excluded_terms = '', $previous = true, $taxonomy = 'category' ) {
2038      $post = get_post();
2039      if ( $previous && is_attachment() && $post ) {
2040          $post = get_post( $post->post_parent );
2041      } else {
2042          $post = get_adjacent_post( $in_same_term, $excluded_terms, $previous, $taxonomy );
2043      }
2044  
2045      if ( empty( $post ) ) {
2046          return;
2047      }
2048  
2049      $post_title = the_title_attribute(
2050          array(
2051              'echo' => false,
2052              'post' => $post,
2053          )
2054      );
2055  
2056      if ( empty( $post_title ) ) {
2057          $post_title = $previous ? __( 'Previous Post' ) : __( 'Next Post' );
2058      }
2059  
2060      $date = mysql2date( get_option( 'date_format' ), $post->post_date );
2061  
2062      $title = str_replace( '%title', $post_title, $title );
2063      $title = str_replace( '%date', $date, $title );
2064  
2065      $link  = $previous ? "<link rel='prev' title='" : "<link rel='next' title='";
2066      $link .= esc_attr( $title );
2067      $link .= "' href='" . get_permalink( $post ) . "' />\n";
2068  
2069      $adjacent = $previous ? 'previous' : 'next';
2070  
2071      /**
2072       * Filters the adjacent post relational link.
2073       *
2074       * The dynamic portion of the hook name, `$adjacent`, refers to the type
2075       * of adjacency, 'next' or 'previous'.
2076       *
2077       * Possible hook names include:
2078       *
2079       *  - `next_post_rel_link`
2080       *  - `previous_post_rel_link`
2081       *
2082       * @since 2.8.0
2083       *
2084       * @param string $link The relational link.
2085       */
2086      return apply_filters( "{$adjacent}_post_rel_link", $link );
2087  }
2088  
2089  /**
2090   * Displays the relational links for the posts adjacent to the current post.
2091   *
2092   * @since 2.8.0
2093   *
2094   * @param string       $title          Optional. Link title format. Default '%title'.
2095   * @param bool         $in_same_term   Optional. Whether link should be in the same taxonomy term.
2096   *                                     Default false.
2097   * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs.
2098   *                                     Default empty.
2099   * @param string       $taxonomy       Optional. Taxonomy, if `$in_same_term` is true. Default 'category'.
2100   */
2101  function adjacent_posts_rel_link( $title = '%title', $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
2102      echo get_adjacent_post_rel_link( $title, $in_same_term, $excluded_terms, true, $taxonomy );
2103      echo get_adjacent_post_rel_link( $title, $in_same_term, $excluded_terms, false, $taxonomy );
2104  }
2105  
2106  /**
2107   * Displays relational links for the posts adjacent to the current post for single post pages.
2108   *
2109   * This is meant to be attached to actions like 'wp_head'. Do not call this directly in plugins
2110   * or theme templates.
2111   *
2112   * @since 3.0.0
2113   * @since 5.6.0 No longer used in core.
2114   *
2115   * @see adjacent_posts_rel_link()
2116   */
2117  function adjacent_posts_rel_link_wp_head() {
2118      if ( ! is_single() || is_attachment() ) {
2119          return;
2120      }
2121      adjacent_posts_rel_link();
2122  }
2123  
2124  /**
2125   * Displays the relational link for the next post adjacent to the current post.
2126   *
2127   * @since 2.8.0
2128   *
2129   * @see get_adjacent_post_rel_link()
2130   *
2131   * @param string       $title          Optional. Link title format. Default '%title'.
2132   * @param bool         $in_same_term   Optional. Whether link should be in the same taxonomy term.
2133   *                                     Default false.
2134   * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs.
2135   *                                     Default empty.
2136   * @param string       $taxonomy       Optional. Taxonomy, if `$in_same_term` is true. Default 'category'.
2137   */
2138  function next_post_rel_link( $title = '%title', $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
2139      echo get_adjacent_post_rel_link( $title, $in_same_term, $excluded_terms, false, $taxonomy );
2140  }
2141  
2142  /**
2143   * Displays the relational link for the previous post adjacent to the current post.
2144   *
2145   * @since 2.8.0
2146   *
2147   * @see get_adjacent_post_rel_link()
2148   *
2149   * @param string       $title          Optional. Link title format. Default '%title'.
2150   * @param bool         $in_same_term   Optional. Whether link should be in the same taxonomy term.
2151   *                                     Default false.
2152   * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs.
2153   *                                     Default true.
2154   * @param string       $taxonomy       Optional. Taxonomy, if `$in_same_term` is true. Default 'category'.
2155   */
2156  function prev_post_rel_link( $title = '%title', $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
2157      echo get_adjacent_post_rel_link( $title, $in_same_term, $excluded_terms, true, $taxonomy );
2158  }
2159  
2160  /**
2161   * Retrieves the boundary post.
2162   *
2163   * Boundary being either the first or last post by publish date within the constraints specified
2164   * by `$in_same_term` or `$excluded_terms`.
2165   *
2166   * @since 2.8.0
2167   *
2168   * @param bool         $in_same_term   Optional. Whether returned post should be in the same taxonomy term.
2169   *                                     Default false.
2170   * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs.
2171   *                                     Default empty.
2172   * @param bool         $start          Optional. Whether to retrieve first or last post.
2173   *                                     Default true.
2174   * @param string       $taxonomy       Optional. Taxonomy, if `$in_same_term` is true. Default 'category'.
2175   * @return array|null Array containing the boundary post object if successful, null otherwise.
2176   */
2177  function get_boundary_post( $in_same_term = false, $excluded_terms = '', $start = true, $taxonomy = 'category' ) {
2178      $post = get_post();
2179  
2180      if ( ! $post || ! is_single() || is_attachment() || ! taxonomy_exists( $taxonomy ) ) {
2181          return null;
2182      }
2183  
2184      $query_args = array(
2185          'posts_per_page'         => 1,
2186          'order'                  => $start ? 'ASC' : 'DESC',
2187          'update_post_term_cache' => false,
2188          'update_post_meta_cache' => false,
2189      );
2190  
2191      $term_array = array();
2192  
2193      if ( ! is_array( $excluded_terms ) ) {
2194          if ( ! empty( $excluded_terms ) ) {
2195              $excluded_terms = explode( ',', $excluded_terms );
2196          } else {
2197              $excluded_terms = array();
2198          }
2199      }
2200  
2201      if ( $in_same_term || ! empty( $excluded_terms ) ) {
2202          if ( $in_same_term ) {
2203              $term_array = wp_get_object_terms( $post->ID, $taxonomy, array( 'fields' => 'ids' ) );
2204          }
2205  
2206          if ( ! empty( $excluded_terms ) ) {
2207              $excluded_terms = array_map( 'intval', $excluded_terms );
2208              $excluded_terms = array_diff( $excluded_terms, $term_array );
2209  
2210              $inverse_terms = array();
2211              foreach ( $excluded_terms as $excluded_term ) {
2212                  $inverse_terms[] = $excluded_term * -1;
2213              }
2214              $excluded_terms = $inverse_terms;
2215          }
2216  
2217          $query_args['tax_query'] = array(
2218              array(
2219                  'taxonomy' => $taxonomy,
2220                  'terms'    => array_merge( $term_array, $excluded_terms ),
2221              ),
2222          );
2223      }
2224  
2225      return get_posts( $query_args );
2226  }
2227  
2228  /**
2229   * Retrieves the previous post link that is adjacent to the current post.
2230   *
2231   * @since 3.7.0
2232   *
2233   * @param string       $format         Optional. Link anchor format. Default '&laquo; %link'.
2234   * @param string       $link           Optional. Link permalink format. Default '%title'.
2235   * @param bool         $in_same_term   Optional. Whether link should be in the same taxonomy term.
2236   *                                     Default false.
2237   * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs.
2238   *                                     Default empty.
2239   * @param string       $taxonomy       Optional. Taxonomy, if `$in_same_term` is true. Default 'category'.
2240   * @return string The link URL of the previous post in relation to the current post.
2241   */
2242  function get_previous_post_link( $format = '&laquo; %link', $link = '%title', $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
2243      return get_adjacent_post_link( $format, $link, $in_same_term, $excluded_terms, true, $taxonomy );
2244  }
2245  
2246  /**
2247   * Displays the previous post link that is adjacent to the current post.
2248   *
2249   * @since 1.5.0
2250   *
2251   * @see get_previous_post_link()
2252   *
2253   * @param string       $format         Optional. Link anchor format. Default '&laquo; %link'.
2254   * @param string       $link           Optional. Link permalink format. Default '%title'.
2255   * @param bool         $in_same_term   Optional. Whether link should be in the same taxonomy term.
2256   *                                     Default false.
2257   * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs.
2258   *                                     Default empty.
2259   * @param string       $taxonomy       Optional. Taxonomy, if `$in_same_term` is true. Default 'category'.
2260   */
2261  function previous_post_link( $format = '&laquo; %link', $link = '%title', $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
2262      echo get_previous_post_link( $format, $link, $in_same_term, $excluded_terms, $taxonomy );
2263  }
2264  
2265  /**
2266   * Retrieves the next post link that is adjacent to the current post.
2267   *
2268   * @since 3.7.0
2269   *
2270   * @param string       $format         Optional. Link anchor format. Default '&laquo; %link'.
2271   * @param string       $link           Optional. Link permalink format. Default '%title'.
2272   * @param bool         $in_same_term   Optional. Whether link should be in the same taxonomy term.
2273   *                                     Default false.
2274   * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs.
2275   *                                     Default empty.
2276   * @param string       $taxonomy       Optional. Taxonomy, if `$in_same_term` is true. Default 'category'.
2277   * @return string The link URL of the next post in relation to the current post.
2278   */
2279  function get_next_post_link( $format = '%link &raquo;', $link = '%title', $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
2280      return get_adjacent_post_link( $format, $link, $in_same_term, $excluded_terms, false, $taxonomy );
2281  }
2282  
2283  /**
2284   * Displays the next post link that is adjacent to the current post.
2285   *
2286   * @since 1.5.0
2287   *
2288   * @see get_next_post_link()
2289   *
2290   * @param string       $format         Optional. Link anchor format. Default '&laquo; %link'.
2291   * @param string       $link           Optional. Link permalink format. Default '%title'.
2292   * @param bool         $in_same_term   Optional. Whether link should be in the same taxonomy term.
2293   *                                     Default false.
2294   * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs.
2295   *                                     Default empty.
2296   * @param string       $taxonomy       Optional. Taxonomy, if `$in_same_term` is true. Default 'category'.
2297   */
2298  function next_post_link( $format = '%link &raquo;', $link = '%title', $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
2299      echo get_next_post_link( $format, $link, $in_same_term, $excluded_terms, $taxonomy );
2300  }
2301  
2302  /**
2303   * Retrieves the adjacent post link.
2304   *
2305   * Can be either next post link or previous.
2306   *
2307   * @since 3.7.0
2308   *
2309   * @param string       $format         Link anchor format.
2310   * @param string       $link           Link permalink format.
2311   * @param bool         $in_same_term   Optional. Whether link should be in the same taxonomy term.
2312   *                                     Default false.
2313   * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded terms IDs.
2314   *                                     Default empty.
2315   * @param bool         $previous       Optional. Whether to display link to previous or next post.
2316   *                                     Default true.
2317   * @param string       $taxonomy       Optional. Taxonomy, if `$in_same_term` is true. Default 'category'.
2318   * @return string The link URL of the previous or next post in relation to the current post.
2319   */
2320  function get_adjacent_post_link( $format, $link, $in_same_term = false, $excluded_terms = '', $previous = true, $taxonomy = 'category' ) {
2321      if ( $previous && is_attachment() ) {
2322          $post = get_post( get_post()->post_parent );
2323      } else {
2324          $post = get_adjacent_post( $in_same_term, $excluded_terms, $previous, $taxonomy );
2325      }
2326  
2327      if ( ! $post ) {
2328          $output = '';
2329      } else {
2330          $title = $post->post_title;
2331  
2332          if ( empty( $post->post_title ) ) {
2333              $title = $previous ? __( 'Previous Post' ) : __( 'Next Post' );
2334          }
2335  
2336          /** This filter is documented in wp-includes/post-template.php */
2337          $title = apply_filters( 'the_title', $title, $post->ID );
2338  
2339          $date = mysql2date( get_option( 'date_format' ), $post->post_date );
2340          $rel  = $previous ? 'prev' : 'next';
2341  
2342          $string = '<a href="' . get_permalink( $post ) . '" rel="' . $rel . '">';
2343          $inlink = str_replace( '%title', $title, $link );
2344          $inlink = str_replace( '%date', $date, $inlink );
2345          $inlink = $string . $inlink . '</a>';
2346  
2347          $output = str_replace( '%link', $inlink, $format );
2348      }
2349  
2350      $adjacent = $previous ? 'previous' : 'next';
2351  
2352      /**
2353       * Filters the adjacent post link.
2354       *
2355       * The dynamic portion of the hook name, `$adjacent`, refers to the type
2356       * of adjacency, 'next' or 'previous'.
2357       *
2358       * Possible hook names include:
2359       *
2360       *  - `next_post_link`
2361       *  - `previous_post_link`
2362       *
2363       * @since 2.6.0
2364       * @since 4.2.0 Added the `$adjacent` parameter.
2365       *
2366       * @param string         $output   The adjacent post link.
2367       * @param string         $format   Link anchor format.
2368       * @param string         $link     Link permalink format.
2369       * @param WP_Post|string $post     The adjacent post. Empty string if no corresponding post exists.
2370       * @param string         $adjacent Whether the post is previous or next.
2371       */
2372      return apply_filters( "{$adjacent}_post_link", $output, $format, $link, $post, $adjacent );
2373  }
2374  
2375  /**
2376   * Displays the adjacent post link.
2377   *
2378   * Can be either next post link or previous.
2379   *
2380   * @since 2.5.0
2381   *
2382   * @param string       $format         Link anchor format.
2383   * @param string       $link           Link permalink format.
2384   * @param bool         $in_same_term   Optional. Whether link should be in the same taxonomy term.
2385   *                                     Default false.
2386   * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded category IDs.
2387   *                                     Default empty.
2388   * @param bool         $previous       Optional. Whether to display link to previous or next post.
2389   *                                     Default true.
2390   * @param string       $taxonomy       Optional. Taxonomy, if `$in_same_term` is true. Default 'category'.
2391   */
2392  function adjacent_post_link( $format, $link, $in_same_term = false, $excluded_terms = '', $previous = true, $taxonomy = 'category' ) {
2393      echo get_adjacent_post_link( $format, $link, $in_same_term, $excluded_terms, $previous, $taxonomy );
2394  }
2395  
2396  /**
2397   * Retrieves the link for a page number.
2398   *
2399   * @since 1.5.0
2400   *
2401   * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
2402   *
2403   * @param int  $pagenum Optional. Page number. Default 1.
2404   * @param bool $escape  Optional. Whether to escape the URL for display, with esc_url().
2405   *                      If set to false, prepares the URL with sanitize_url(). Default true.
2406   * @return string The link URL for the given page number.
2407   */
2408  function get_pagenum_link( $pagenum = 1, $escape = true ) {
2409      global $wp_rewrite;
2410  
2411      $pagenum = (int) $pagenum;
2412  
2413      $request = remove_query_arg( 'paged' );
2414  
2415      $home_root = parse_url( home_url() );
2416      $home_root = ( isset( $home_root['path'] ) ) ? $home_root['path'] : '';
2417      $home_root = preg_quote( $home_root, '|' );
2418  
2419      $request = preg_replace( '|^' . $home_root . '|i', '', $request );
2420      $request = preg_replace( '|^/+|', '', $request );
2421  
2422      if ( ! $wp_rewrite->using_permalinks() || is_admin() ) {
2423          $base = trailingslashit( get_bloginfo( 'url' ) );
2424  
2425          if ( $pagenum > 1 ) {
2426              $result = add_query_arg( 'paged', $pagenum, $base . $request );
2427          } else {
2428              $result = $base . $request;
2429          }
2430      } else {
2431          $qs_regex = '|\?.*?$|';
2432          preg_match( $qs_regex, $request, $qs_match );
2433  
2434          if ( ! empty( $qs_match[0] ) ) {
2435              $query_string = $qs_match[0];
2436              $request      = preg_replace( $qs_regex, '', $request );
2437          } else {
2438              $query_string = '';
2439          }
2440  
2441          $request = preg_replace( "|$wp_rewrite->pagination_base/\d+/?$|", '', $request );
2442          $request = preg_replace( '|^' . preg_quote( $wp_rewrite->index, '|' ) . '|i', '', $request );
2443          $request = ltrim( $request, '/' );
2444  
2445          $base = trailingslashit( get_bloginfo( 'url' ) );
2446  
2447          if ( $wp_rewrite->using_index_permalinks() && ( $pagenum > 1 || '' !== $request ) ) {
2448              $base .= $wp_rewrite->index . '/';
2449          }
2450  
2451          if ( $pagenum > 1 ) {
2452              $request = ( ( ! empty( $request ) ) ? trailingslashit( $request ) : $request ) . user_trailingslashit( $wp_rewrite->pagination_base . '/' . $pagenum, 'paged' );
2453          }
2454  
2455          $result = $base . $request . $query_string;
2456      }
2457  
2458      /**
2459       * Filters the page number link for the current request.
2460       *
2461       * @since 2.5.0
2462       * @since 5.2.0 Added the `$pagenum` argument.
2463       *
2464       * @param string $result  The page number link.
2465       * @param int    $pagenum The page number.
2466       */
2467      $result = apply_filters( 'get_pagenum_link', $result, $pagenum );
2468  
2469      if ( $escape ) {
2470          return esc_url( $result );
2471      } else {
2472          return sanitize_url( $result );
2473      }
2474  }
2475  
2476  /**
2477   * Retrieves the next posts page link.
2478   *
2479   * Backported from 2.1.3 to 2.0.10.
2480   *
2481   * @since 2.0.10
2482   *
2483   * @global int $paged
2484   *
2485   * @param int $max_page Optional. Max pages. Default 0.
2486   * @return string|void The link URL for next posts page.
2487   */
2488  function get_next_posts_page_link( $max_page = 0 ) {
2489      global $paged;
2490  
2491      if ( ! is_single() ) {
2492          if ( ! $paged ) {
2493              $paged = 1;
2494          }
2495  
2496          $next_page = (int) $paged + 1;
2497  
2498          if ( ! $max_page || $max_page >= $next_page ) {
2499              return get_pagenum_link( $next_page );
2500          }
2501      }
2502  }
2503  
2504  /**
2505   * Displays or retrieves the next posts page link.
2506   *
2507   * @since 0.71
2508   *
2509   * @param int  $max_page Optional. Max pages. Default 0.
2510   * @param bool $display  Optional. Whether to echo the link. Default true.
2511   * @return string|void The link URL for next posts page if `$display = false`.
2512   */
2513  function next_posts( $max_page = 0, $display = true ) {
2514      $output = esc_url( get_next_posts_page_link( $max_page ) );
2515  
2516      if ( $display ) {
2517          echo $output;
2518      } else {
2519          return $output;
2520      }
2521  }
2522  
2523  /**
2524   * Retrieves the next posts page link.
2525   *
2526   * @since 2.7.0
2527   *
2528   * @global int      $paged
2529   * @global WP_Query $wp_query WordPress Query object.
2530   *
2531   * @param string $label    Content for link text.
2532   * @param int    $max_page Optional. Max pages. Default 0.
2533   * @return string|void HTML-formatted next posts page link.
2534   */
2535  function get_next_posts_link( $label = null, $max_page = 0 ) {
2536      global $paged, $wp_query;
2537  
2538      if ( ! $max_page ) {
2539          $max_page = $wp_query->max_num_pages;
2540      }
2541  
2542      if ( ! $paged ) {
2543          $paged = 1;
2544      }
2545  
2546      $next_page = (int) $paged + 1;
2547  
2548      if ( null === $label ) {
2549          $label = __( 'Next Page &raquo;' );
2550      }
2551  
2552      if ( ! is_single() && ( $next_page <= $max_page ) ) {
2553          /**
2554           * Filters the anchor tag attributes for the next posts page link.
2555           *
2556           * @since 2.7.0
2557           *
2558           * @param string $attributes Attributes for the anchor tag.
2559           */
2560          $attr = apply_filters( 'next_posts_link_attributes', '' );
2561  
2562          return sprintf(
2563              '<a href="%1$s" %2$s>%3$s</a>',
2564              next_posts( $max_page, false ),
2565              $attr,
2566              preg_replace( '/&([^#])(?![a-z]{1,8};)/i', '&#038;$1', $label )
2567          );
2568      }
2569  }
2570  
2571  /**
2572   * Displays the next posts page link.
2573   *
2574   * @since 0.71
2575   *
2576   * @param string $label    Content for link text.
2577   * @param int    $max_page Optional. Max pages. Default 0.
2578   */
2579  function next_posts_link( $label = null, $max_page = 0 ) {
2580      echo get_next_posts_link( $label, $max_page );
2581  }
2582  
2583  /**
2584   * Retrieves the previous posts page link.
2585   *
2586   * Will only return string, if not on a single page or post.
2587   *
2588   * Backported to 2.0.10 from 2.1.3.
2589   *
2590   * @since 2.0.10
2591   *
2592   * @global int $paged
2593   *
2594   * @return string|void The link for the previous posts page.
2595   */
2596  function get_previous_posts_page_link() {
2597      global $paged;
2598  
2599      if ( ! is_single() ) {
2600          $previous_page = (int) $paged - 1;
2601  
2602          if ( $previous_page < 1 ) {
2603              $previous_page = 1;
2604          }
2605  
2606          return get_pagenum_link( $previous_page );
2607      }
2608  }
2609  
2610  /**
2611   * Displays or retrieves the previous posts page link.
2612   *
2613   * @since 0.71
2614   *
2615   * @param bool $display Optional. Whether to echo the link. Default true.
2616   * @return string|void The previous posts page link if `$display = false`.
2617   */
2618  function previous_posts( $display = true ) {
2619      $output = esc_url( get_previous_posts_page_link() );
2620  
2621      if ( $display ) {
2622          echo $output;
2623      } else {
2624          return $output;
2625      }
2626  }
2627  
2628  /**
2629   * Retrieves the previous posts page link.
2630   *
2631   * @since 2.7.0
2632   *
2633   * @global int $paged
2634   *
2635   * @param string $label Optional. Previous page link text.
2636   * @return string|void HTML-formatted previous page link.
2637   */
2638  function get_previous_posts_link( $label = null ) {
2639      global $paged;
2640  
2641      if ( null === $label ) {
2642          $label = __( '&laquo; Previous Page' );
2643      }
2644  
2645      if ( ! is_single() && $paged > 1 ) {
2646          /**
2647           * Filters the anchor tag attributes for the previous posts page link.
2648           *
2649           * @since 2.7.0
2650           *
2651           * @param string $attributes Attributes for the anchor tag.
2652           */
2653          $attr = apply_filters( 'previous_posts_link_attributes', '' );
2654  
2655          return sprintf(
2656              '<a href="%1$s" %2$s>%3$s</a>',
2657              previous_posts( false ),
2658              $attr,
2659              preg_replace( '/&([^#])(?![a-z]{1,8};)/i', '&#038;$1', $label )
2660          );
2661      }
2662  }
2663  
2664  /**
2665   * Displays the previous posts page link.
2666   *
2667   * @since 0.71
2668   *
2669   * @param string $label Optional. Previous page link text.
2670   */
2671  function previous_posts_link( $label = null ) {
2672      echo get_previous_posts_link( $label );
2673  }
2674  
2675  /**
2676   * Retrieves the post pages link navigation for previous and next pages.
2677   *
2678   * @since 2.8.0
2679   *
2680   * @global WP_Query $wp_query WordPress Query object.
2681   *
2682   * @param string|array $args {
2683   *     Optional. Arguments to build the post pages link navigation.
2684   *
2685   *     @type string $sep      Separator character. Default '&#8212;'.
2686   *     @type string $prelabel Link text to display for the previous page link.
2687   *                            Default '&laquo; Previous Page'.
2688   *     @type string $nxtlabel Link text to display for the next page link.
2689   *                            Default 'Next Page &raquo;'.
2690   * }
2691   * @return string The posts link navigation.
2692   */
2693  function get_posts_nav_link( $args = array() ) {
2694      global $wp_query;
2695  
2696      $return = '';
2697  
2698      if ( ! is_singular() ) {
2699          $defaults = array(
2700              'sep'      => ' &#8212; ',
2701              'prelabel' => __( '&laquo; Previous Page' ),
2702              'nxtlabel' => __( 'Next Page &raquo;' ),
2703          );
2704          $args     = wp_parse_args( $args, $defaults );
2705  
2706          $max_num_pages = $wp_query->max_num_pages;
2707          $paged         = get_query_var( 'paged' );
2708  
2709          // Only have sep if there's both prev and next results.
2710          if ( $paged < 2 || $paged >= $max_num_pages ) {
2711              $args['sep'] = '';
2712          }
2713  
2714          if ( $max_num_pages > 1 ) {
2715              $return  = get_previous_posts_link( $args['prelabel'] );
2716              $return .= preg_replace( '/&([^#])(?![a-z]{1,8};)/i', '&#038;$1', $args['sep'] );
2717              $return .= get_next_posts_link( $args['nxtlabel'] );
2718          }
2719      }
2720      return $return;
2721  }
2722  
2723  /**
2724   * Displays the post pages link navigation for previous and next pages.
2725   *
2726   * @since 0.71
2727   *
2728   * @param string $sep      Optional. Separator for posts navigation links. Default empty.
2729   * @param string $prelabel Optional. Label for previous pages. Default empty.
2730   * @param string $nxtlabel Optional Label for next pages. Default empty.
2731   */
2732  function posts_nav_link( $sep = '', $prelabel = '', $nxtlabel = '' ) {
2733      $args = array_filter( compact( 'sep', 'prelabel', 'nxtlabel' ) );
2734      echo get_posts_nav_link( $args );
2735  }
2736  
2737  /**
2738   * Retrieves the navigation to next/previous post, when applicable.
2739   *
2740   * @since 4.1.0
2741   * @since 4.4.0 Introduced the `in_same_term`, `excluded_terms`, and `taxonomy` arguments.
2742   * @since 5.3.0 Added the `aria_label` parameter.
2743   * @since 5.5.0 Added the `class` parameter.
2744   *
2745   * @param array $args {
2746   *     Optional. Default post navigation arguments. Default empty array.
2747   *
2748   *     @type string       $prev_text          Anchor text to display in the previous post link.
2749   *                                            Default '%title'.
2750   *     @type string       $next_text          Anchor text to display in the next post link.
2751   *                                            Default '%title'.
2752   *     @type bool         $in_same_term       Whether link should be in the same taxonomy term.
2753   *                                            Default false.
2754   *     @type int[]|string $excluded_terms     Array or comma-separated list of excluded term IDs.
2755   *                                            Default empty.
2756   *     @type string       $taxonomy           Taxonomy, if `$in_same_term` is true. Default 'category'.
2757   *     @type string       $screen_reader_text Screen reader text for the nav element.
2758   *                                            Default 'Post navigation'.
2759   *     @type string       $aria_label         ARIA label text for the nav element. Default 'Posts'.
2760   *     @type string       $class              Custom class for the nav element. Default 'post-navigation'.
2761   * }
2762   * @return string Markup for post links.
2763   */
2764  function get_the_post_navigation( $args = array() ) {
2765      // Make sure the nav element has an aria-label attribute: fallback to the screen reader text.
2766      if ( ! empty( $args['screen_reader_text'] ) && empty( $args['aria_label'] ) ) {
2767          $args['aria_label'] = $args['screen_reader_text'];
2768      }
2769  
2770      $args = wp_parse_args(
2771          $args,
2772          array(
2773              'prev_text'          => '%title',
2774              'next_text'          => '%title',
2775              'in_same_term'       => false,
2776              'excluded_terms'     => '',
2777              'taxonomy'           => 'category',
2778              'screen_reader_text' => __( 'Post navigation' ),
2779              'aria_label'         => __( 'Posts' ),
2780              'class'              => 'post-navigation',
2781          )
2782      );
2783  
2784      $navigation = '';
2785  
2786      $previous = get_previous_post_link(
2787          '<div class="nav-previous">%link</div>',
2788          $args['prev_text'],
2789          $args['in_same_term'],
2790          $args['excluded_terms'],
2791          $args['taxonomy']
2792      );
2793  
2794      $next = get_next_post_link(
2795          '<div class="nav-next">%link</div>',
2796          $args['next_text'],
2797          $args['in_same_term'],
2798          $args['excluded_terms'],
2799          $args['taxonomy']
2800      );
2801  
2802      // Only add markup if there's somewhere to navigate to.
2803      if ( $previous || $next ) {
2804          $navigation = _navigation_markup( $previous . $next, $args['class'], $args['screen_reader_text'], $args['aria_label'] );
2805      }
2806  
2807      return $navigation;
2808  }
2809  
2810  /**
2811   * Displays the navigation to next/previous post, when applicable.
2812   *
2813   * @since 4.1.0
2814   *
2815   * @param array $args Optional. See get_the_post_navigation() for available arguments.
2816   *                    Default empty array.
2817   */
2818  function the_post_navigation( $args = array() ) {
2819      echo get_the_post_navigation( $args );
2820  }
2821  
2822  /**
2823   * Returns the navigation to next/previous set of posts, when applicable.
2824   *
2825   * @since 4.1.0
2826   * @since 5.3.0 Added the `aria_label` parameter.
2827   * @since 5.5.0 Added the `class` parameter.
2828   *
2829   * @global WP_Query $wp_query WordPress Query object.
2830   *
2831   * @param array $args {
2832   *     Optional. Default posts navigation arguments. Default empty array.
2833   *
2834   *     @type string $prev_text          Anchor text to display in the previous posts link.
2835   *                                      Default 'Older posts'.
2836   *     @type string $next_text          Anchor text to display in the next posts link.
2837   *                                      Default 'Newer posts'.
2838   *     @type string $screen_reader_text Screen reader text for the nav element.
2839   *                                      Default 'Posts navigation'.
2840   *     @type string $aria_label         ARIA label text for the nav element. Default 'Posts'.
2841   *     @type string $class              Custom class for the nav element. Default 'posts-navigation'.
2842   * }
2843   * @return string Markup for posts links.
2844   */
2845  function get_the_posts_navigation( $args = array() ) {
2846      global $wp_query;
2847  
2848      $navigation = '';
2849  
2850      // Don't print empty markup if there's only one page.
2851      if ( $wp_query->max_num_pages > 1 ) {
2852          // Make sure the nav element has an aria-label attribute: fallback to the screen reader text.
2853          if ( ! empty( $args['screen_reader_text'] ) && empty( $args['aria_label'] ) ) {
2854              $args['aria_label'] = $args['screen_reader_text'];
2855          }
2856  
2857          $args = wp_parse_args(
2858              $args,
2859              array(
2860                  'prev_text'          => __( 'Older posts' ),
2861                  'next_text'          => __( 'Newer posts' ),
2862                  'screen_reader_text' => __( 'Posts navigation' ),
2863                  'aria_label'         => __( 'Posts' ),
2864                  'class'              => 'posts-navigation',
2865              )
2866          );
2867  
2868          $next_link = get_previous_posts_link( $args['next_text'] );
2869          $prev_link = get_next_posts_link( $args['prev_text'] );
2870  
2871          if ( $prev_link ) {
2872              $navigation .= '<div class="nav-previous">' . $prev_link . '</div>';
2873          }
2874  
2875          if ( $next_link ) {
2876              $navigation .= '<div class="nav-next">' . $next_link . '</div>';
2877          }
2878  
2879          $navigation = _navigation_markup( $navigation, $args['class'], $args['screen_reader_text'], $args['aria_label'] );
2880      }
2881  
2882      return $navigation;
2883  }
2884  
2885  /**
2886   * Displays the navigation to next/previous set of posts, when applicable.
2887   *
2888   * @since 4.1.0
2889   *
2890   * @param array $args Optional. See get_the_posts_navigation() for available arguments.
2891   *                    Default empty array.
2892   */
2893  function the_posts_navigation( $args = array() ) {
2894      echo get_the_posts_navigation( $args );
2895  }
2896  
2897  /**
2898   * Retrieves a paginated navigation to next/previous set of posts, when applicable.
2899   *
2900   * @since 4.1.0
2901   * @since 5.3.0 Added the `aria_label` parameter.
2902   * @since 5.5.0 Added the `class` parameter.
2903   *
2904   * @global WP_Query $wp_query WordPress Query object.
2905   *
2906   * @param array $args {
2907   *     Optional. Default pagination arguments, see paginate_links().
2908   *
2909   *     @type string $screen_reader_text Screen reader text for navigation element.
2910   *                                      Default 'Posts navigation'.
2911   *     @type string $aria_label         ARIA label text for the nav element. Default 'Posts'.
2912   *     @type string $class              Custom class for the nav element. Default 'pagination'.
2913   * }
2914   * @return string Markup for pagination links.
2915   */
2916  function get_the_posts_pagination( $args = array() ) {
2917      global $wp_query;
2918  
2919      $navigation = '';
2920  
2921      // Don't print empty markup if there's only one page.
2922      if ( $wp_query->max_num_pages > 1 ) {
2923          // Make sure the nav element has an aria-label attribute: fallback to the screen reader text.
2924          if ( ! empty( $args['screen_reader_text'] ) && empty( $args['aria_label'] ) ) {
2925              $args['aria_label'] = $args['screen_reader_text'];
2926          }
2927  
2928          $args = wp_parse_args(
2929              $args,
2930              array(
2931                  'mid_size'           => 1,
2932                  'prev_text'          => _x( 'Previous', 'previous set of posts' ),
2933                  'next_text'          => _x( 'Next', 'next set of posts' ),
2934                  'screen_reader_text' => __( 'Posts navigation' ),
2935                  'aria_label'         => __( 'Posts' ),
2936                  'class'              => 'pagination',
2937              )
2938          );
2939  
2940          /**
2941           * Filters the arguments for posts pagination links.
2942           *
2943           * @since 6.1.0
2944           *
2945           * @param array $args {
2946           *     Optional. Default pagination arguments, see paginate_links().
2947           *
2948           *     @type string $screen_reader_text Screen reader text for navigation element.
2949           *                                      Default 'Posts navigation'.
2950           *     @type string $aria_label         ARIA label text for the nav element. Default 'Posts'.
2951           *     @type string $class              Custom class for the nav element. Default 'pagination'.
2952           * }
2953           */
2954          $args = apply_filters( 'the_posts_pagination_args', $args );
2955  
2956          // Make sure we get a string back. Plain is the next best thing.
2957          if ( isset( $args['type'] ) && 'array' === $args['type'] ) {
2958              $args['type'] = 'plain';
2959          }
2960  
2961          // Set up paginated links.
2962          $links = paginate_links( $args );
2963  
2964          if ( $links ) {
2965              $navigation = _navigation_markup( $links, $args['class'], $args['screen_reader_text'], $args['aria_label'] );
2966          }
2967      }
2968  
2969      return $navigation;
2970  }
2971  
2972  /**
2973   * Displays a paginated navigation to next/previous set of posts, when applicable.
2974   *
2975   * @since 4.1.0
2976   *
2977   * @param array $args Optional. See get_the_posts_pagination() for available arguments.
2978   *                    Default empty array.
2979   */
2980  function the_posts_pagination( $args = array() ) {
2981      echo get_the_posts_pagination( $args );
2982  }
2983  
2984  /**
2985   * Wraps passed links in navigational markup.
2986   *
2987   * @since 4.1.0
2988   * @since 5.3.0 Added the `aria_label` parameter.
2989   * @access private
2990   *
2991   * @param string $links              Navigational links.
2992   * @param string $css_class          Optional. Custom class for the nav element.
2993   *                                   Default 'posts-navigation'.
2994   * @param string $screen_reader_text Optional. Screen reader text for the nav element.
2995   *                                   Default 'Posts navigation'.
2996   * @param string $aria_label         Optional. ARIA label for the nav element.
2997   *                                   Defaults to the value of `$screen_reader_text`.
2998   * @return string Navigation template tag.
2999   */
3000  function _navigation_markup( $links, $css_class = 'posts-navigation', $screen_reader_text = '', $aria_label = '' ) {
3001      if ( empty( $screen_reader_text ) ) {
3002          $screen_reader_text = /* translators: Hidden accessibility text. */ __( 'Posts navigation' );
3003      }
3004      if ( empty( $aria_label ) ) {
3005          $aria_label = $screen_reader_text;
3006      }
3007  
3008      $template = '
3009      <nav class="navigation %1$s" aria-label="%4$s">
3010          <h2 class="screen-reader-text">%2$s</h2>
3011          <div class="nav-links">%3$s</div>
3012      </nav>';
3013  
3014      /**
3015       * Filters the navigation markup template.
3016       *
3017       * Note: The filtered template HTML must contain specifiers for the navigation
3018       * class (%1$s), the screen-reader-text value (%2$s), placement of the navigation
3019       * links (%3$s), and ARIA label text if screen-reader-text does not fit that (%4$s):
3020       *
3021       *     <nav class="navigation %1$s" aria-label="%4$s">
3022       *         <h2 class="screen-reader-text">%2$s</h2>
3023       *         <div class="nav-links">%3$s</div>
3024       *     </nav>
3025       *
3026       * @since 4.4.0
3027       *
3028       * @param string $template  The default template.
3029       * @param string $css_class The class passed by the calling function.
3030       * @return string Navigation template.
3031       */
3032      $template = apply_filters( 'navigation_markup_template', $template, $css_class );
3033  
3034      return sprintf( $template, sanitize_html_class( $css_class ), esc_html( $screen_reader_text ), $links, esc_attr( $aria_label ) );
3035  }
3036  
3037  /**
3038   * Retrieves the comments page number link.
3039   *
3040   * @since 2.7.0
3041   *
3042   * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
3043   *
3044   * @param int $pagenum  Optional. Page number. Default 1.
3045   * @param int $max_page Optional. The maximum number of comment pages. Default 0.
3046   * @return string The comments page number link URL.
3047   */
3048  function get_comments_pagenum_link( $pagenum = 1, $max_page = 0 ) {
3049      global $wp_rewrite;
3050  
3051      $pagenum = (int) $pagenum;
3052  
3053      $result = get_permalink();
3054  
3055      if ( 'newest' === get_option( 'default_comments_page' ) ) {
3056          if ( $pagenum != $max_page ) {
3057              if ( $wp_rewrite->using_permalinks() ) {
3058                  $result = user_trailingslashit( trailingslashit( $result ) . $wp_rewrite->comments_pagination_base . '-' . $pagenum, 'commentpaged' );
3059              } else {
3060                  $result = add_query_arg( 'cpage', $pagenum, $result );
3061              }
3062          }
3063      } elseif ( $pagenum > 1 ) {
3064          if ( $wp_rewrite->using_permalinks() ) {
3065              $result = user_trailingslashit( trailingslashit( $result ) . $wp_rewrite->comments_pagination_base . '-' . $pagenum, 'commentpaged' );
3066          } else {
3067              $result = add_query_arg( 'cpage', $pagenum, $result );
3068          }
3069      }
3070  
3071      $result .= '#comments';
3072  
3073      /**
3074       * Filters the comments page number link for the current request.
3075       *
3076       * @since 2.7.0
3077       *
3078       * @param string $result The comments page number link.
3079       */
3080      return apply_filters( 'get_comments_pagenum_link', $result );
3081  }
3082  
3083  /**
3084   * Retrieves the link to the next comments page.
3085   *
3086   * @since 2.7.1
3087   *
3088   * @global WP_Query $wp_query WordPress Query object.
3089   *
3090   * @param string $label    Optional. Label for link text. Default empty.
3091   * @param int    $max_page Optional. Max page. Default 0.
3092   * @return string|void HTML-formatted link for the next page of comments.
3093   */
3094  function get_next_comments_link( $label = '', $max_page = 0 ) {
3095      global $wp_query;
3096  
3097      if ( ! is_singular() ) {
3098          return;
3099      }
3100  
3101      $page = get_query_var( 'cpage' );
3102  
3103      if ( ! $page ) {
3104          $page = 1;
3105      }
3106  
3107      $next_page = (int) $page + 1;
3108  
3109      if ( empty( $max_page ) ) {
3110          $max_page = $wp_query->max_num_comment_pages;
3111      }
3112  
3113      if ( empty( $max_page ) ) {
3114          $max_page = get_comment_pages_count();
3115      }
3116  
3117      if ( $next_page > $max_page ) {
3118          return;
3119      }
3120  
3121      if ( empty( $label ) ) {
3122          $label = __( 'Newer Comments &raquo;' );
3123      }
3124  
3125      /**
3126       * Filters the anchor tag attributes for the next comments page link.
3127       *
3128       * @since 2.7.0
3129       *
3130       * @param string $attributes Attributes for the anchor tag.
3131       */
3132      $attr = apply_filters( 'next_comments_link_attributes', '' );
3133  
3134      return sprintf(
3135          '<a href="%1$s" %2$s>%3$s</a>',
3136          esc_url( get_comments_pagenum_link( $next_page, $max_page ) ),
3137          $attr,
3138          preg_replace( '/&([^#])(?![a-z]{1,8};)/i', '&#038;$1', $label )
3139      );
3140  }
3141  
3142  /**
3143   * Displays the link to the next comments page.
3144   *
3145   * @since 2.7.0
3146   *
3147   * @param string $label    Optional. Label for link text. Default empty.
3148   * @param int    $max_page Optional. Max page. Default 0.
3149   */
3150  function next_comments_link( $label = '', $max_page = 0 ) {
3151      echo get_next_comments_link( $label, $max_page );
3152  }
3153  
3154  /**
3155   * Retrieves the link to the previous comments page.
3156   *
3157   * @since 2.7.1
3158   *
3159   * @param string $label Optional. Label for comments link text. Default empty.
3160   * @return string|void HTML-formatted link for the previous page of comments.
3161   */
3162  function get_previous_comments_link( $label = '' ) {
3163      if ( ! is_singular() ) {
3164          return;
3165      }
3166  
3167      $page = get_query_var( 'cpage' );
3168  
3169      if ( (int) $page <= 1 ) {
3170          return;
3171      }
3172  
3173      $previous_page = (int) $page - 1;
3174  
3175      if ( empty( $label ) ) {
3176          $label = __( '&laquo; Older Comments' );
3177      }
3178  
3179      /**
3180       * Filters the anchor tag attributes for the previous comments page link.
3181       *
3182       * @since 2.7.0
3183       *
3184       * @param string $attributes Attributes for the anchor tag.
3185       */
3186      $attr = apply_filters( 'previous_comments_link_attributes', '' );
3187  
3188      return sprintf(
3189          '<a href="%1$s" %2$s>%3$s</a>',
3190          esc_url( get_comments_pagenum_link( $previous_page ) ),
3191          $attr,
3192          preg_replace( '/&([^#])(?![a-z]{1,8};)/i', '&#038;$1', $label )
3193      );
3194  }
3195  
3196  /**
3197   * Displays the link to the previous comments page.
3198   *
3199   * @since 2.7.0
3200   *
3201   * @param string $label Optional. Label for comments link text. Default empty.
3202   */
3203  function previous_comments_link( $label = '' ) {
3204      echo get_previous_comments_link( $label );
3205  }
3206  
3207  /**
3208   * Displays or retrieves pagination links for the comments on the current post.
3209   *
3210   * @see paginate_links()
3211   * @since 2.7.0
3212   *
3213   * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
3214   *
3215   * @param string|array $args Optional args. See paginate_links(). Default empty array.
3216   * @return void|string|array Void if 'echo' argument is true and 'type' is not an array,
3217   *                           or if the query is not for an existing single post of any post type.
3218   *                           Otherwise, markup for comment page links or array of comment page links,
3219   *                           depending on 'type' argument.
3220   */
3221  function paginate_comments_links( $args = array() ) {
3222      global $wp_rewrite;
3223  
3224      if ( ! is_singular() ) {
3225          return;
3226      }
3227  
3228      $page = get_query_var( 'cpage' );
3229      if ( ! $page ) {
3230          $page = 1;
3231      }
3232      $max_page = get_comment_pages_count();
3233      $defaults = array(
3234          'base'         => add_query_arg( 'cpage', '%#%' ),
3235          'format'       => '',
3236          'total'        => $max_page,
3237          'current'      => $page,
3238          'echo'         => true,
3239          'type'         => 'plain',
3240          'add_fragment' => '#comments',
3241      );
3242      if ( $wp_rewrite->using_permalinks() ) {
3243          $defaults['base'] = user_trailingslashit( trailingslashit( get_permalink() ) . $wp_rewrite->comments_pagination_base . '-%#%', 'commentpaged' );
3244      }
3245  
3246      $args       = wp_parse_args( $args, $defaults );
3247      $page_links = paginate_links( $args );
3248  
3249      if ( $args['echo'] && 'array' !== $args['type'] ) {
3250          echo $page_links;
3251      } else {
3252          return $page_links;
3253      }
3254  }
3255  
3256  /**
3257   * Retrieves navigation to next/previous set of comments, when applicable.
3258   *
3259   * @since 4.4.0
3260   * @since 5.3.0 Added the `aria_label` parameter.
3261   * @since 5.5.0 Added the `class` parameter.
3262   *
3263   * @param array $args {
3264   *     Optional. Default comments navigation arguments.
3265   *
3266   *     @type string $prev_text          Anchor text to display in the previous comments link.
3267   *                                      Default 'Older comments'.
3268   *     @type string $next_text          Anchor text to display in the next comments link.
3269   *                                      Default 'Newer comments'.
3270   *     @type string $screen_reader_text Screen reader text for the nav element. Default 'Comments navigation'.
3271   *     @type string $aria_label         ARIA label text for the nav element. Default 'Comments'.
3272   *     @type string $class              Custom class for the nav element. Default 'comment-navigation'.
3273   * }
3274   * @return string Markup for comments links.
3275   */
3276  function get_the_comments_navigation( $args = array() ) {
3277      $navigation = '';
3278  
3279      // Are there comments to navigate through?
3280      if ( get_comment_pages_count() > 1 ) {
3281          // Make sure the nav element has an aria-label attribute: fallback to the screen reader text.
3282          if ( ! empty( $args['screen_reader_text'] ) && empty( $args['aria_label'] ) ) {
3283              $args['aria_label'] = $args['screen_reader_text'];
3284          }
3285  
3286          $args = wp_parse_args(
3287              $args,
3288              array(
3289                  'prev_text'          => __( 'Older comments' ),
3290                  'next_text'          => __( 'Newer comments' ),
3291                  'screen_reader_text' => __( 'Comments navigation' ),
3292                  'aria_label'         => __( 'Comments' ),
3293                  'class'              => 'comment-navigation',
3294              )
3295          );
3296  
3297          $prev_link = get_previous_comments_link( $args['prev_text'] );
3298          $next_link = get_next_comments_link( $args['next_text'] );
3299  
3300          if ( $prev_link ) {
3301              $navigation .= '<div class="nav-previous">' . $prev_link . '</div>';
3302          }
3303  
3304          if ( $next_link ) {
3305              $navigation .= '<div class="nav-next">' . $next_link . '</div>';
3306          }
3307  
3308          $navigation = _navigation_markup( $navigation, $args['class'], $args['screen_reader_text'], $args['aria_label'] );
3309      }
3310  
3311      return $navigation;
3312  }
3313  
3314  /**
3315   * Displays navigation to next/previous set of comments, when applicable.
3316   *
3317   * @since 4.4.0
3318   *
3319   * @param array $args See get_the_comments_navigation() for available arguments. Default empty array.
3320   */
3321  function the_comments_navigation( $args = array() ) {
3322      echo get_the_comments_navigation( $args );
3323  }
3324  
3325  /**
3326   * Retrieves a paginated navigation to next/previous set of comments, when applicable.
3327   *
3328   * @since 4.4.0
3329   * @since 5.3.0 Added the `aria_label` parameter.
3330   * @since 5.5.0 Added the `class` parameter.
3331   *
3332   * @see paginate_comments_links()
3333   *
3334   * @param array $args {
3335   *     Optional. Default pagination arguments.
3336   *
3337   *     @type string $screen_reader_text Screen reader text for the nav element. Default 'Comments navigation'.
3338   *     @type string $aria_label         ARIA label text for the nav element. Default 'Comments'.
3339   *     @type string $class              Custom class for the nav element. Default 'comments-pagination'.
3340   * }
3341   * @return string Markup for pagination links.
3342   */
3343  function get_the_comments_pagination( $args = array() ) {
3344      $navigation = '';
3345  
3346      // Make sure the nav element has an aria-label attribute: fallback to the screen reader text.
3347      if ( ! empty( $args['screen_reader_text'] ) && empty( $args['aria_label'] ) ) {
3348          $args['aria_label'] = $args['screen_reader_text'];
3349      }
3350  
3351      $args         = wp_parse_args(
3352          $args,
3353          array(
3354              'screen_reader_text' => __( 'Comments navigation' ),
3355              'aria_label'         => __( 'Comments' ),
3356              'class'              => 'comments-pagination',
3357          )
3358      );
3359      $args['echo'] = false;
3360  
3361      // Make sure we get a string back. Plain is the next best thing.
3362      if ( isset( $args['type'] ) && 'array' === $args['type'] ) {
3363          $args['type'] = 'plain';
3364      }
3365  
3366      $links = paginate_comments_links( $args );
3367  
3368      if ( $links ) {
3369          $navigation = _navigation_markup( $links, $args['class'], $args['screen_reader_text'], $args['aria_label'] );
3370      }
3371  
3372      return $navigation;
3373  }
3374  
3375  /**
3376   * Displays a paginated navigation to next/previous set of comments, when applicable.
3377   *
3378   * @since 4.4.0
3379   *
3380   * @param array $args See get_the_comments_pagination() for available arguments. Default empty array.
3381   */
3382  function the_comments_pagination( $args = array() ) {
3383      echo get_the_comments_pagination( $args );
3384  }
3385  
3386  /**
3387   * Retrieves the URL for the current site where the front end is accessible.
3388   *
3389   * Returns the 'home' option with the appropriate protocol. The protocol will be 'https'
3390   * if is_ssl() evaluates to true; otherwise, it will be the same as the 'home' option.
3391   * If `$scheme` is 'http' or 'https', is_ssl() is overridden.
3392   *
3393   * @since 3.0.0
3394   *
3395   * @param string      $path   Optional. Path relative to the home URL. Default empty.
3396   * @param string|null $scheme Optional. Scheme to give the home URL context. Accepts
3397   *                            'http', 'https', 'relative', 'rest', or null. Default null.
3398   * @return string Home URL link with optional path appended.
3399   */
3400  function home_url( $path = '', $scheme = null ) {
3401      return get_home_url( null, $path, $scheme );
3402  }
3403  
3404  /**
3405   * Retrieves the URL for a given site where the front end is accessible.
3406   *
3407   * Returns the 'home' option with the appropriate protocol. The protocol will be 'https'
3408   * if is_ssl() evaluates to true; otherwise, it will be the same as the 'home' option.
3409   * If `$scheme` is 'http' or 'https', is_ssl() is overridden.
3410   *
3411   * @since 3.0.0
3412   *
3413   * @param int|null    $blog_id Optional. Site ID. Default null (current site).
3414   * @param string      $path    Optional. Path relative to the home URL. Default empty.
3415   * @param string|null $scheme  Optional. Scheme to give the home URL context. Accepts
3416   *                             'http', 'https', 'relative', 'rest', or null. Default null.
3417   * @return string Home URL link with optional path appended.
3418   */
3419  function get_home_url( $blog_id = null, $path = '', $scheme = null ) {
3420      $orig_scheme = $scheme;
3421  
3422      if ( empty( $blog_id ) || ! is_multisite() ) {
3423          $url = get_option( 'home' );
3424      } else {
3425          switch_to_blog( $blog_id );
3426          $url = get_option( 'home' );
3427          restore_current_blog();
3428      }
3429  
3430      if ( ! in_array( $scheme, array( 'http', 'https', 'relative' ), true ) ) {
3431          if ( is_ssl() ) {
3432              $scheme = 'https';
3433          } else {
3434              $scheme = parse_url( $url, PHP_URL_SCHEME );
3435          }
3436      }
3437  
3438      $url = set_url_scheme( $url, $scheme );
3439  
3440      if ( $path && is_string( $path ) ) {
3441          $url .= '/' . ltrim( $path, '/' );
3442      }
3443  
3444      /**
3445       * Filters the home URL.
3446       *
3447       * @since 3.0.0
3448       *
3449       * @param string      $url         The complete home URL including scheme and path.
3450       * @param string      $path        Path relative to the home URL. Blank string if no path is specified.
3451       * @param string|null $orig_scheme Scheme to give the home URL context. Accepts 'http', 'https',
3452       *                                 'relative', 'rest', or null.
3453       * @param int|null    $blog_id     Site ID, or null for the current site.
3454       */
3455      return apply_filters( 'home_url', $url, $path, $orig_scheme, $blog_id );
3456  }
3457  
3458  /**
3459   * Retrieves the URL for the current site where WordPress application files
3460   * (e.g. wp-blog-header.php or the wp-admin/ folder) are accessible.
3461   *
3462   * Returns the 'site_url' option with the appropriate protocol, 'https' if
3463   * is_ssl() and 'http' otherwise. If $scheme is 'http' or 'https', is_ssl() is
3464   * overridden.
3465   *
3466   * @since 3.0.0
3467   *
3468   * @param string      $path   Optional. Path relative to the site URL. Default empty.
3469   * @param string|null $scheme Optional. Scheme to give the site URL context. See set_url_scheme().
3470   * @return string Site URL link with optional path appended.
3471   */
3472  function site_url( $path = '', $scheme = null ) {
3473      return get_site_url( null, $path, $scheme );
3474  }
3475  
3476  /**
3477   * Retrieves the URL for a given site where WordPress application files
3478   * (e.g. wp-blog-header.php or the wp-admin/ folder) are accessible.
3479   *
3480   * Returns the 'site_url' option with the appropriate protocol, 'https' if
3481   * is_ssl() and 'http' otherwise. If `$scheme` is 'http' or 'https',
3482   * `is_ssl()` is overridden.
3483   *
3484   * @since 3.0.0
3485   *
3486   * @param int|null    $blog_id Optional. Site ID. Default null (current site).
3487   * @param string      $path    Optional. Path relative to the site URL. Default empty.
3488   * @param string|null $scheme  Optional. Scheme to give the site URL context. Accepts
3489   *                             'http', 'https', 'login', 'login_post', 'admin', or
3490   *                             'relative'. Default null.
3491   * @return string Site URL link with optional path appended.
3492   */
3493  function get_site_url( $blog_id = null, $path = '', $scheme = null ) {
3494      if ( empty( $blog_id ) || ! is_multisite() ) {
3495          $url = get_option( 'siteurl' );
3496      } else {
3497          switch_to_blog( $blog_id );
3498          $url = get_option( 'siteurl' );
3499          restore_current_blog();
3500      }
3501  
3502      $url = set_url_scheme( $url, $scheme );
3503  
3504      if ( $path && is_string( $path ) ) {
3505          $url .= '/' . ltrim( $path, '/' );
3506      }
3507  
3508      /**
3509       * Filters the site URL.
3510       *
3511       * @since 2.7.0
3512       *
3513       * @param string      $url     The complete site URL including scheme and path.
3514       * @param string      $path    Path relative to the site URL. Blank string if no path is specified.
3515       * @param string|null $scheme  Scheme to give the site URL context. Accepts 'http', 'https', 'login',
3516       *                             'login_post', 'admin', 'relative' or null.
3517       * @param int|null    $blog_id Site ID, or null for the current site.
3518       */
3519      return apply_filters( 'site_url', $url, $path, $scheme, $blog_id );
3520  }
3521  
3522  /**
3523   * Retrieves the URL to the admin area for the current site.
3524   *
3525   * @since 2.6.0
3526   *
3527   * @param string $path   Optional. Path relative to the admin URL. Default empty.
3528   * @param string $scheme The scheme to use. Default is 'admin', which obeys force_ssl_admin() and is_ssl().
3529   *                       'http' or 'https' can be passed to force those schemes.
3530   * @return string Admin URL link with optional path appended.
3531   */
3532  function admin_url( $path = '', $scheme = 'admin' ) {
3533      return get_admin_url( null, $path, $scheme );
3534  }
3535  
3536  /**
3537   * Retrieves the URL to the admin area for a given site.
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 admin URL. Default empty.
3543   * @param string   $scheme  Optional. The scheme to use. Accepts 'http' or 'https',
3544   *                          to force those schemes. Default 'admin', which obeys
3545   *                          force_ssl_admin() and is_ssl().
3546   * @return string Admin URL link with optional path appended.
3547   */
3548  function get_admin_url( $blog_id = null, $path = '', $scheme = 'admin' ) {
3549      $url = get_site_url( $blog_id, 'wp-admin/', $scheme );
3550  
3551      if ( $path && is_string( $path ) ) {
3552          $url .= ltrim( $path, '/' );
3553      }
3554  
3555      /**
3556       * Filters the admin area URL.
3557       *
3558       * @since 2.8.0
3559       * @since 5.8.0 The `$scheme` parameter was added.
3560       *
3561       * @param string      $url     The complete admin area URL including scheme and path.
3562       * @param string      $path    Path relative to the admin area URL. Blank string if no path is specified.
3563       * @param int|null    $blog_id Site ID, or null for the current site.
3564       * @param string|null $scheme  The scheme to use. Accepts 'http', 'https',
3565       *                             'admin', or null. Default 'admin', which obeys force_ssl_admin() and is_ssl().
3566       */
3567      return apply_filters( 'admin_url', $url, $path, $blog_id, $scheme );
3568  }
3569  
3570  /**
3571   * Retrieves the URL to the includes directory.
3572   *
3573   * @since 2.6.0
3574   *
3575   * @param string      $path   Optional. Path relative to the includes URL. Default empty.
3576   * @param string|null $scheme Optional. Scheme to give the includes URL context. Accepts
3577   *                            'http', 'https', or 'relative'. Default null.
3578   * @return string Includes URL link with optional path appended.
3579   */
3580  function includes_url( $path = '', $scheme = null ) {
3581      $url = site_url( '/' . WPINC . '/', $scheme );
3582  
3583      if ( $path && is_string( $path ) ) {
3584          $url .= ltrim( $path, '/' );
3585      }
3586  
3587      /**
3588       * Filters the URL to the includes directory.
3589       *
3590       * @since 2.8.0
3591       * @since 5.8.0 The `$scheme` parameter was added.
3592       *
3593       * @param string      $url    The complete URL to the includes directory including scheme and path.
3594       * @param string      $path   Path relative to the URL to the wp-includes directory. Blank string
3595       *                            if no path is specified.
3596       * @param string|null $scheme Scheme to give the includes URL context. Accepts
3597       *                            'http', 'https', 'relative', or null. Default null.
3598       */
3599      return apply_filters( 'includes_url', $url, $path, $scheme );
3600  }
3601  
3602  /**
3603   * Retrieves the URL to the content directory.
3604   *
3605   * @since 2.6.0
3606   *
3607   * @param string $path Optional. Path relative to the content URL. Default empty.
3608   * @return string Content URL link with optional path appended.
3609   */
3610  function content_url( $path = '' ) {
3611      $url = set_url_scheme( WP_CONTENT_URL );
3612  
3613      if ( $path && is_string( $path ) ) {
3614          $url .= '/' . ltrim( $path, '/' );
3615      }
3616  
3617      /**
3618       * Filters the URL to the content directory.
3619       *
3620       * @since 2.8.0
3621       *
3622       * @param string $url  The complete URL to the content directory including scheme and path.
3623       * @param string $path Path relative to the URL to the content directory. Blank string
3624       *                     if no path is specified.
3625       */
3626      return apply_filters( 'content_url', $url, $path );
3627  }
3628  
3629  /**
3630   * Retrieves a URL within the plugins or mu-plugins directory.
3631   *
3632   * Defaults to the plugins directory URL if no arguments are supplied.
3633   *
3634   * @since 2.6.0
3635   *
3636   * @param string $path   Optional. Extra path appended to the end of the URL, including
3637   *                       the relative directory if $plugin is supplied. Default empty.
3638   * @param string $plugin Optional. A full path to a file inside a plugin or mu-plugin.
3639   *                       The URL will be relative to its directory. Default empty.
3640   *                       Typically this is done by passing `__FILE__` as the argument.
3641   * @return string Plugins URL link with optional paths appended.
3642   */
3643  function plugins_url( $path = '', $plugin = '' ) {
3644  
3645      $path          = wp_normalize_path( $path );
3646      $plugin        = wp_normalize_path( $plugin );
3647      $mu_plugin_dir = wp_normalize_path( WPMU_PLUGIN_DIR );
3648  
3649      if ( ! empty( $plugin ) && str_starts_with( $plugin, $mu_plugin_dir ) ) {
3650          $url = WPMU_PLUGIN_URL;
3651      } else {
3652          $url = WP_PLUGIN_URL;
3653      }
3654  
3655      $url = set_url_scheme( $url );
3656  
3657      if ( ! empty( $plugin ) && is_string( $plugin ) ) {
3658          $folder = dirname( plugin_basename( $plugin ) );
3659          if ( '.' !== $folder ) {
3660              $url .= '/' . ltrim( $folder, '/' );
3661          }
3662      }
3663  
3664      if ( $path && is_string( $path ) ) {
3665          $url .= '/' . ltrim( $path, '/' );
3666      }
3667  
3668      /**
3669       * Filters the URL to the plugins directory.
3670       *
3671       * @since 2.8.0
3672       *
3673       * @param string $url    The complete URL to the plugins directory including scheme and path.
3674       * @param string $path   Path relative to the URL to the plugins directory. Blank string
3675       *                       if no path is specified.
3676       * @param string $plugin The plugin file path to be relative to. Blank string if no plugin
3677       *                       is specified.
3678       */
3679      return apply_filters( 'plugins_url', $url, $path, $plugin );
3680  }
3681  
3682  /**
3683   * Retrieves the site URL for the current network.
3684   *
3685   * Returns the site URL with the appropriate protocol, 'https' if
3686   * is_ssl() and 'http' otherwise. If $scheme is 'http' or 'https', is_ssl() is
3687   * overridden.
3688   *
3689   * @since 3.0.0
3690   *
3691   * @see set_url_scheme()
3692   *
3693   * @param string      $path   Optional. Path relative to the site URL. Default empty.
3694   * @param string|null $scheme Optional. Scheme to give the site URL context. Accepts
3695   *                            'http', 'https', or 'relative'. Default null.
3696   * @return string Site URL link with optional path appended.
3697   */
3698  function network_site_url( $path = '', $scheme = null ) {
3699      if ( ! is_multisite() ) {
3700          return site_url( $path, $scheme );
3701      }
3702  
3703      $current_network = get_network();
3704  
3705      if ( 'relative' === $scheme ) {
3706          $url = $current_network->path;
3707      } else {
3708          $url = set_url_scheme( 'http://' . $current_network->domain . $current_network->path, $scheme );
3709      }
3710  
3711      if ( $path && is_string( $path ) ) {
3712          $url .= ltrim( $path, '/' );
3713      }
3714  
3715      /**
3716       * Filters the network site URL.
3717       *
3718       * @since 3.0.0
3719       *
3720       * @param string      $url    The complete network site URL including scheme and path.
3721       * @param string      $path   Path relative to the network site URL. Blank string if
3722       *                            no path is specified.
3723       * @param string|null $scheme Scheme to give the URL context. Accepts 'http', 'https',
3724       *                            'relative' or null.
3725       */
3726      return apply_filters( 'network_site_url', $url, $path, $scheme );
3727  }
3728  
3729  /**
3730   * Retrieves the home URL for the current network.
3731   *
3732   * Returns the home URL with the appropriate protocol, 'https' is_ssl()
3733   * and 'http' otherwise. If `$scheme` is 'http' or 'https', `is_ssl()` is
3734   * overridden.
3735   *
3736   * @since 3.0.0
3737   *
3738   * @param string      $path   Optional. Path relative to the home URL. Default empty.
3739   * @param string|null $scheme Optional. Scheme to give the home URL context. Accepts
3740   *                            'http', 'https', or 'relative'. Default null.
3741   * @return string Home URL link with optional path appended.
3742   */
3743  function network_home_url( $path = '', $scheme = null ) {
3744      if ( ! is_multisite() ) {
3745          return home_url( $path, $scheme );
3746      }
3747  
3748      $current_network = get_network();
3749      $orig_scheme     = $scheme;
3750  
3751      if ( ! in_array( $scheme, array( 'http', 'https', 'relative' ), true ) ) {
3752          $scheme = is_ssl() ? 'https' : 'http';
3753      }
3754  
3755      if ( 'relative' === $scheme ) {
3756          $url = $current_network->path;
3757      } else {
3758          $url = set_url_scheme( 'http://' . $current_network->domain . $current_network->path, $scheme );
3759      }
3760  
3761      if ( $path && is_string( $path ) ) {
3762          $url .= ltrim( $path, '/' );
3763      }
3764  
3765      /**
3766       * Filters the network home URL.
3767       *
3768       * @since 3.0.0
3769       *
3770       * @param string      $url         The complete network home URL including scheme and path.
3771       * @param string      $path        Path relative to the network home URL. Blank string
3772       *                                 if no path is specified.
3773       * @param string|null $orig_scheme Scheme to give the URL context. Accepts 'http', 'https',
3774       *                                 'relative' or null.
3775       */
3776      return apply_filters( 'network_home_url', $url, $path, $orig_scheme );
3777  }
3778  
3779  /**
3780   * Retrieves the URL to the admin area for the network.
3781   *
3782   * @since 3.0.0
3783   *
3784   * @param string $path   Optional path relative to the admin URL. Default empty.
3785   * @param string $scheme Optional. The scheme to use. Default is 'admin', which obeys force_ssl_admin()
3786   *                       and is_ssl(). 'http' or 'https' can be passed to force those schemes.
3787   * @return string Admin URL link with optional path appended.
3788   */
3789  function network_admin_url( $path = '', $scheme = 'admin' ) {
3790      if ( ! is_multisite() ) {
3791          return admin_url( $path, $scheme );
3792      }
3793  
3794      $url = network_site_url( 'wp-admin/network/', $scheme );
3795  
3796      if ( $path && is_string( $path ) ) {
3797          $url .= ltrim( $path, '/' );
3798      }
3799  
3800      /**
3801       * Filters the network admin URL.
3802       *
3803       * @since 3.0.0
3804       * @since 5.8.0 The `$scheme` parameter was added.
3805       *
3806       * @param string      $url    The complete network admin URL including scheme and path.
3807       * @param string      $path   Path relative to the network admin URL. Blank string if
3808       *                            no path is specified.
3809       * @param string|null $scheme The scheme to use. Accepts 'http', 'https',
3810       *                            'admin', or null. Default is 'admin', which obeys force_ssl_admin() and is_ssl().
3811       */
3812      return apply_filters( 'network_admin_url', $url, $path, $scheme );
3813  }
3814  
3815  /**
3816   * Retrieves the URL to the admin area for the current user.
3817   *
3818   * @since 3.0.0
3819   *
3820   * @param string $path   Optional. Path relative to the admin URL. Default empty.
3821   * @param string $scheme Optional. The scheme to use. Default is 'admin', which obeys force_ssl_admin()
3822   *                       and is_ssl(). 'http' or 'https' can be passed to force those schemes.
3823   * @return string Admin URL link with optional path appended.
3824   */
3825  function user_admin_url( $path = '', $scheme = 'admin' ) {
3826      $url = network_site_url( 'wp-admin/user/', $scheme );
3827  
3828      if ( $path && is_string( $path ) ) {
3829          $url .= ltrim( $path, '/' );
3830      }
3831  
3832      /**
3833       * Filters the user admin URL for the current user.
3834       *
3835       * @since 3.1.0
3836       * @since 5.8.0 The `$scheme` parameter was added.
3837       *
3838       * @param string      $url    The complete URL including scheme and path.
3839       * @param string      $path   Path relative to the URL. Blank string if
3840       *                            no path is specified.
3841       * @param string|null $scheme The scheme to use. Accepts 'http', 'https',
3842       *                            'admin', or null. Default is 'admin', which obeys force_ssl_admin() and is_ssl().
3843       */
3844      return apply_filters( 'user_admin_url', $url, $path, $scheme );
3845  }
3846  
3847  /**
3848   * Retrieves the URL to the admin area for either the current site or the network depending on context.
3849   *
3850   * @since 3.1.0
3851   *
3852   * @param string $path   Optional. Path relative to the admin URL. Default empty.
3853   * @param string $scheme Optional. The scheme to use. Default is 'admin', which obeys force_ssl_admin()
3854   *                       and is_ssl(). 'http' or 'https' can be passed to force those schemes.
3855   * @return string Admin URL link with optional path appended.
3856   */
3857  function self_admin_url( $path = '', $scheme = 'admin' ) {
3858      if ( is_network_admin() ) {
3859          $url = network_admin_url( $path, $scheme );
3860      } elseif ( is_user_admin() ) {
3861          $url = user_admin_url( $path, $scheme );
3862      } else {
3863          $url = admin_url( $path, $scheme );
3864      }
3865  
3866      /**
3867       * Filters the admin URL for the current site or network depending on context.
3868       *
3869       * @since 4.9.0
3870       *
3871       * @param string $url    The complete URL including scheme and path.
3872       * @param string $path   Path relative to the URL. Blank string if no path is specified.
3873       * @param string $scheme The scheme to use.
3874       */
3875      return apply_filters( 'self_admin_url', $url, $path, $scheme );
3876  }
3877  
3878  /**
3879   * Sets the scheme for a URL.
3880   *
3881   * @since 3.4.0
3882   * @since 4.4.0 The 'rest' scheme was added.
3883   *
3884   * @param string      $url    Absolute URL that includes a scheme
3885   * @param string|null $scheme Optional. Scheme to give $url. Currently 'http', 'https', 'login',
3886   *                            'login_post', 'admin', 'relative', 'rest', 'rpc', or null. Default null.
3887   * @return string URL with chosen scheme.
3888   */
3889  function set_url_scheme( $url, $scheme = null ) {
3890      $orig_scheme = $scheme;
3891  
3892      if ( ! $scheme ) {
3893          $scheme = is_ssl() ? 'https' : 'http';
3894      } elseif ( 'admin' === $scheme || 'login' === $scheme || 'login_post' === $scheme || 'rpc' === $scheme ) {
3895          $scheme = is_ssl() || force_ssl_admin() ? 'https' : 'http';
3896      } elseif ( 'http' !== $scheme && 'https' !== $scheme && 'relative' !== $scheme ) {
3897          $scheme = is_ssl() ? 'https' : 'http';
3898      }
3899  
3900      $url = trim( $url );
3901      if ( str_starts_with( $url, '//' ) ) {
3902          $url = 'http:' . $url;
3903      }
3904  
3905      if ( 'relative' === $scheme ) {
3906          $url = ltrim( preg_replace( '#^\w+://[^/]*#', '', $url ) );
3907          if ( '' !== $url && '/' === $url[0] ) {
3908              $url = '/' . ltrim( $url, "/ \t\n\r\0\x0B" );
3909          }
3910      } else {
3911          $url = preg_replace( '#^\w+://#', $scheme . '://', $url );
3912      }
3913  
3914      /**
3915       * Filters the resulting URL after setting the scheme.
3916       *
3917       * @since 3.4.0
3918       *
3919       * @param string      $url         The complete URL including scheme and path.
3920       * @param string      $scheme      Scheme applied to the URL. One of 'http', 'https', or 'relative'.
3921       * @param string|null $orig_scheme Scheme requested for the URL. One of 'http', 'https', 'login',
3922       *                                 'login_post', 'admin', 'relative', 'rest', 'rpc', or null.
3923       */
3924      return apply_filters( 'set_url_scheme', $url, $scheme, $orig_scheme );
3925  }
3926  
3927  /**
3928   * Retrieves the URL to the user's dashboard.
3929   *
3930   * If a user does not belong to any site, the global user dashboard is used. If the user
3931   * belongs to the current site, the dashboard for the current site is returned. If the user
3932   * cannot edit the current site, the dashboard to the user's primary site is returned.
3933   *
3934   * @since 3.1.0
3935   *
3936   * @param int    $user_id Optional. User ID. Defaults to current user.
3937   * @param string $path    Optional path relative to the dashboard. Use only paths known to
3938   *                        both site and user admins. Default empty.
3939   * @param string $scheme  The scheme to use. Default is 'admin', which obeys force_ssl_admin()
3940   *                        and is_ssl(). 'http' or 'https' can be passed to force those schemes.
3941   * @return string Dashboard URL link with optional path appended.
3942   */
3943  function get_dashboard_url( $user_id = 0, $path = '', $scheme = 'admin' ) {
3944      $user_id = $user_id ? (int) $user_id : get_current_user_id();
3945  
3946      $blogs = get_blogs_of_user( $user_id );
3947  
3948      if ( is_multisite() && ! user_can( $user_id, 'manage_network' ) && empty( $blogs ) ) {
3949          $url = user_admin_url( $path, $scheme );
3950      } elseif ( ! is_multisite() ) {
3951          $url = admin_url( $path, $scheme );
3952      } else {
3953          $current_blog = get_current_blog_id();
3954  
3955          if ( $current_blog && ( user_can( $user_id, 'manage_network' ) || in_array( $current_blog, array_keys( $blogs ), true ) ) ) {
3956              $url = admin_url( $path, $scheme );
3957          } else {
3958              $active = get_active_blog_for_user( $user_id );
3959              if ( $active ) {
3960                  $url = get_admin_url( $active->blog_id, $path, $scheme );
3961              } else {
3962                  $url = user_admin_url( $path, $scheme );
3963              }
3964          }
3965      }
3966  
3967      /**
3968       * Filters the dashboard URL for a user.
3969       *
3970       * @since 3.1.0
3971       *
3972       * @param string $url     The complete URL including scheme and path.
3973       * @param int    $user_id The user ID.
3974       * @param string $path    Path relative to the URL. Blank string if no path is specified.
3975       * @param string $scheme  Scheme to give the URL context. Accepts 'http', 'https', 'login',
3976       *                        'login_post', 'admin', 'relative' or null.
3977       */
3978      return apply_filters( 'user_dashboard_url', $url, $user_id, $path, $scheme );
3979  }
3980  
3981  /**
3982   * Retrieves the URL to the user's profile editor.
3983   *
3984   * @since 3.1.0
3985   *
3986   * @param int    $user_id Optional. User ID. Defaults to current user.
3987   * @param string $scheme  Optional. The scheme to use. Default is 'admin', which obeys force_ssl_admin()
3988   *                        and is_ssl(). 'http' or 'https' can be passed to force those schemes.
3989   * @return string Dashboard URL link with optional path appended.
3990   */
3991  function get_edit_profile_url( $user_id = 0, $scheme = 'admin' ) {
3992      $user_id = $user_id ? (int) $user_id : get_current_user_id();
3993  
3994      if ( is_user_admin() ) {
3995          $url = user_admin_url( 'profile.php', $scheme );
3996      } elseif ( is_network_admin() ) {
3997          $url = network_admin_url( 'profile.php', $scheme );
3998      } else {
3999          $url = get_dashboard_url( $user_id, 'profile.php', $scheme );
4000      }
4001  
4002      /**
4003       * Filters the URL for a user's profile editor.
4004       *
4005       * @since 3.1.0
4006       *
4007       * @param string $url     The complete URL including scheme and path.
4008       * @param int    $user_id The user ID.
4009       * @param string $scheme  Scheme to give the URL context. Accepts 'http', 'https', 'login',
4010       *                        'login_post', 'admin', 'relative' or null.
4011       */
4012      return apply_filters( 'edit_profile_url', $url, $user_id, $scheme );
4013  }
4014  
4015  /**
4016   * Returns the canonical URL for a post.
4017   *
4018   * When the post is the same as the current requested page the function will handle the
4019   * pagination arguments too.
4020   *
4021   * @since 4.6.0
4022   *
4023   * @param int|WP_Post $post Optional. Post ID or object. Default is global `$post`.
4024   * @return string|false The canonical URL. False if the post does not exist
4025   *                      or has not been published yet.
4026   */
4027  function wp_get_canonical_url( $post = null ) {
4028      $post = get_post( $post );
4029  
4030      if ( ! $post ) {
4031          return false;
4032      }
4033  
4034      if ( 'publish' !== $post->post_status ) {
4035          return false;
4036      }
4037  
4038      $canonical_url = get_permalink( $post );
4039  
4040      // If a canonical is being generated for the current page, make sure it has pagination if needed.
4041      if ( get_queried_object_id() === $post->ID ) {
4042          $page = get_query_var( 'page', 0 );
4043          if ( $page >= 2 ) {
4044              if ( ! get_option( 'permalink_structure' ) ) {
4045                  $canonical_url = add_query_arg( 'page', $page, $canonical_url );
4046              } else {
4047                  $canonical_url = trailingslashit( $canonical_url ) . user_trailingslashit( $page, 'single_paged' );
4048              }
4049          }
4050  
4051          $cpage = get_query_var( 'cpage', 0 );
4052          if ( $cpage ) {
4053              $canonical_url = get_comments_pagenum_link( $cpage );
4054          }
4055      }
4056  
4057      /**
4058       * Filters the canonical URL for a post.
4059       *
4060       * @since 4.6.0
4061       *
4062       * @param string  $canonical_url The post's canonical URL.
4063       * @param WP_Post $post          Post object.
4064       */
4065      return apply_filters( 'get_canonical_url', $canonical_url, $post );
4066  }
4067  
4068  /**
4069   * Outputs rel=canonical for singular queries.
4070   *
4071   * @since 2.9.0
4072   * @since 4.6.0 Adjusted to use `wp_get_canonical_url()`.
4073   */
4074  function rel_canonical() {
4075      if ( ! is_singular() ) {
4076          return;
4077      }
4078  
4079      $id = get_queried_object_id();
4080  
4081      if ( 0 === $id ) {
4082          return;
4083      }
4084  
4085      $url = wp_get_canonical_url( $id );
4086  
4087      if ( ! empty( $url ) ) {
4088          echo '<link rel="canonical" href="' . esc_url( $url ) . '" />' . "\n";
4089      }
4090  }
4091  
4092  /**
4093   * Returns a shortlink for a post, page, attachment, or site.
4094   *
4095   * This function exists to provide a shortlink tag that all themes and plugins can target.
4096   * A plugin must hook in to provide the actual shortlinks. Default shortlink support is
4097   * limited to providing ?p= style links for posts. Plugins can short-circuit this function
4098   * via the {@see 'pre_get_shortlink'} filter or filter the output via the {@see 'get_shortlink'}
4099   * filter.
4100   *
4101   * @since 3.0.0
4102   *
4103   * @param int    $id          Optional. A post or site ID. Default is 0, which means the current post or site.
4104   * @param string $context     Optional. Whether the ID is a 'site' ID, 'post' ID, or 'media' ID. If 'post',
4105   *                            the post_type of the post is consulted. If 'query', the current query is consulted
4106   *                            to determine the ID and context. Default 'post'.
4107   * @param bool   $allow_slugs Optional. Whether to allow post slugs in the shortlink. It is up to the plugin how
4108   *                            and whether to honor this. Default true.
4109   * @return string A shortlink or an empty string if no shortlink exists for the requested resource or if shortlinks
4110   *                are not enabled.
4111   */
4112  function wp_get_shortlink( $id = 0, $context = 'post', $allow_slugs = true ) {
4113      /**
4114       * Filters whether to preempt generating a shortlink for the given post.
4115       *
4116       * Returning a value other than false from the filter will short-circuit
4117       * the shortlink generation process, returning that value instead.
4118       *
4119       * @since 3.0.0
4120       *
4121       * @param false|string $return      Short-circuit return value. Either false or a URL string.
4122       * @param int          $id          Post ID, or 0 for the current post.
4123       * @param string       $context     The context for the link. One of 'post' or 'query',
4124       * @param bool         $allow_slugs Whether to allow post slugs in the shortlink.
4125       */
4126      $shortlink = apply_filters( 'pre_get_shortlink', false, $id, $context, $allow_slugs );
4127  
4128      if ( false !== $shortlink ) {
4129          return $shortlink;
4130      }
4131  
4132      $post_id = 0;
4133      if ( 'query' === $context && is_singular() ) {
4134          $post_id = get_queried_object_id();
4135          $post    = get_post( $post_id );
4136      } elseif ( 'post' === $context ) {
4137          $post = get_post( $id );
4138          if ( ! empty( $post->ID ) ) {
4139              $post_id = $post->ID;
4140          }
4141      }
4142  
4143      $shortlink = '';
4144  
4145      // Return `?p=` link for all public post types.
4146      if ( ! empty( $post_id ) ) {
4147          $post_type = get_post_type_object( $post->post_type );
4148  
4149          if ( 'page' === $post->post_type && get_option( 'page_on_front' ) == $post->ID && 'page' === get_option( 'show_on_front' ) ) {
4150              $shortlink = home_url( '/' );
4151          } elseif ( $post_type && $post_type->public ) {
4152              $shortlink = home_url( '?p=' . $post_id );
4153          }
4154      }
4155  
4156      /**
4157       * Filters the shortlink for a post.
4158       *
4159       * @since 3.0.0
4160       *
4161       * @param string $shortlink   Shortlink URL.
4162       * @param int    $id          Post ID, or 0 for the current post.
4163       * @param string $context     The context for the link. One of 'post' or 'query',
4164       * @param bool   $allow_slugs Whether to allow post slugs in the shortlink. Not used by default.
4165       */
4166      return apply_filters( 'get_shortlink', $shortlink, $id, $context, $allow_slugs );
4167  }
4168  
4169  /**
4170   * Injects rel=shortlink into the head if a shortlink is defined for the current page.
4171   *
4172   * Attached to the {@see 'wp_head'} action.
4173   *
4174   * @since 3.0.0
4175   */
4176  function wp_shortlink_wp_head() {
4177      $shortlink = wp_get_shortlink( 0, 'query' );
4178  
4179      if ( empty( $shortlink ) ) {
4180          return;
4181      }
4182  
4183      echo "<link rel='shortlink' href='" . esc_url( $shortlink ) . "' />\n";
4184  }
4185  
4186  /**
4187   * Sends a Link: rel=shortlink header if a shortlink is defined for the current page.
4188   *
4189   * Attached to the {@see 'wp'} action.
4190   *
4191   * @since 3.0.0
4192   */
4193  function wp_shortlink_header() {
4194      if ( headers_sent() ) {
4195          return;
4196      }
4197  
4198      $shortlink = wp_get_shortlink( 0, 'query' );
4199  
4200      if ( empty( $shortlink ) ) {
4201          return;
4202      }
4203  
4204      header( 'Link: <' . $shortlink . '>; rel=shortlink', false );
4205  }
4206  
4207  /**
4208   * Displays the shortlink for a post.
4209   *
4210   * Must be called from inside "The Loop"
4211   *
4212   * Call like the_shortlink( __( 'Shortlinkage FTW' ) )
4213   *
4214   * @since 3.0.0
4215   *
4216   * @param string $text   Optional The link text or HTML to be displayed. Defaults to 'This is the short link.'
4217   * @param string $title  Optional The tooltip for the link. Must be sanitized. Defaults to the sanitized post title.
4218   * @param string $before Optional HTML to display before the link. Default empty.
4219   * @param string $after  Optional HTML to display after the link. Default empty.
4220   */
4221  function the_shortlink( $text = '', $title = '', $before = '', $after = '' ) {
4222      $post = get_post();
4223  
4224      if ( empty( $text ) ) {
4225          $text = __( 'This is the short link.' );
4226      }
4227  
4228      if ( empty( $title ) ) {
4229          $title = the_title_attribute( array( 'echo' => false ) );
4230      }
4231  
4232      $shortlink = wp_get_shortlink( $post->ID );
4233  
4234      if ( ! empty( $shortlink ) ) {
4235          $link = '<a rel="shortlink" href="' . esc_url( $shortlink ) . '" title="' . $title . '">' . $text . '</a>';
4236  
4237          /**
4238           * Filters the short link anchor tag for a post.
4239           *
4240           * @since 3.0.0
4241           *
4242           * @param string $link      Shortlink anchor tag.
4243           * @param string $shortlink Shortlink URL.
4244           * @param string $text      Shortlink's text.
4245           * @param string $title     Shortlink's title attribute.
4246           */
4247          $link = apply_filters( 'the_shortlink', $link, $shortlink, $text, $title );
4248          echo $before, $link, $after;
4249      }
4250  }
4251  
4252  
4253  /**
4254   * Retrieves the avatar URL.
4255   *
4256   * @since 4.2.0
4257   *
4258   * @param mixed $id_or_email The Gravatar to retrieve a URL for. Accepts a user_id, gravatar md5 hash,
4259   *                           user email, WP_User object, WP_Post object, or WP_Comment object.
4260   * @param array $args {
4261   *     Optional. Arguments to use instead of the default arguments.
4262   *
4263   *     @type int    $size           Height and width of the avatar in pixels. Default 96.
4264   *     @type string $default        URL for the default image or a default type. Accepts '404' (return
4265   *                                  a 404 instead of a default image), 'retro' (8bit), 'RoboHash' (robohash),
4266   *                                  'monsterid' (monster), 'wavatar' (cartoon face), 'indenticon' (the "quilt"),
4267   *                                  'mystery', 'mm', or 'mysteryman' (The Oyster Man), 'blank' (transparent GIF),
4268   *                                  or 'gravatar_default' (the Gravatar logo). Default is the value of the
4269   *                                  'avatar_default' option, with a fallback of 'mystery'.
4270   *     @type bool   $force_default  Whether to always show the default image, never the Gravatar. Default false.
4271   *     @type string $rating         What rating to display avatars up to. Accepts 'G', 'PG', 'R', 'X', and are
4272   *                                  judged in that order. Default is the value of the 'avatar_rating' option.
4273   *     @type string $scheme         URL scheme to use. See set_url_scheme() for accepted values.
4274   *                                  Default null.
4275   *     @type array  $processed_args When the function returns, the value will be the processed/sanitized $args
4276   *                                  plus a "found_avatar" guess. Pass as a reference. Default null.
4277   * }
4278   * @return string|false The URL of the avatar on success, false on failure.
4279   */
4280  function get_avatar_url( $id_or_email, $args = null ) {
4281      $args = get_avatar_data( $id_or_email, $args );
4282      return $args['url'];
4283  }
4284  
4285  
4286  /**
4287   * Check if this comment type allows avatars to be retrieved.
4288   *
4289   * @since 5.1.0
4290   *
4291   * @param string $comment_type Comment type to check.
4292   * @return bool Whether the comment type is allowed for retrieving avatars.
4293   */
4294  function is_avatar_comment_type( $comment_type ) {
4295      /**
4296       * Filters the list of allowed comment types for retrieving avatars.
4297       *
4298       * @since 3.0.0
4299       *
4300       * @param array $types An array of content types. Default only contains 'comment'.
4301       */
4302      $allowed_comment_types = apply_filters( 'get_avatar_comment_types', array( 'comment' ) );
4303  
4304      return in_array( $comment_type, (array) $allowed_comment_types, true );
4305  }
4306  
4307  
4308  /**
4309   * Retrieves default data about the avatar.
4310   *
4311   * @since 4.2.0
4312   *
4313   * @param mixed $id_or_email The avatar to retrieve. Accepts a user ID, Gravatar MD5 hash,
4314   *                           user email, WP_User object, WP_Post object, or WP_Comment object.
4315   * @param array $args {
4316   *     Optional. Arguments to use instead of the default arguments.
4317   *
4318   *     @type int    $size           Height and width of the avatar image file in pixels. Default 96.
4319   *     @type int    $height         Display height of the avatar in pixels. Defaults to $size.
4320   *     @type int    $width          Display width of the avatar in pixels. Defaults to $size.
4321   *     @type string $default        URL for the default image or a default type. Accepts '404' (return
4322   *                                  a 404 instead of a default image), 'retro' (8bit), 'monsterid' (monster),
4323   *                                  'wavatar' (cartoon face), 'indenticon' (the "quilt"), 'mystery', 'mm',
4324   *                                  or 'mysteryman' (The Oyster Man), 'blank' (transparent GIF), or
4325   *                                  'gravatar_default' (the Gravatar logo). Default is the value of the
4326   *                                  'avatar_default' option, with a fallback of 'mystery'.
4327   *     @type bool   $force_default  Whether to always show the default image, never the Gravatar. Default false.
4328   *     @type string $rating         What rating to display avatars up to. Accepts 'G', 'PG', 'R', 'X', and are
4329   *                                  judged in that order. Default is the value of the 'avatar_rating' option.
4330   *     @type string $scheme         URL scheme to use. See set_url_scheme() for accepted values.
4331   *                                  Default null.
4332   *     @type array  $processed_args When the function returns, the value will be the processed/sanitized $args
4333   *                                  plus a "found_avatar" guess. Pass as a reference. Default null.
4334   *     @type string $extra_attr     HTML attributes to insert in the IMG element. Is not sanitized. Default empty.
4335   * }
4336   * @return array {
4337   *     Along with the arguments passed in `$args`, this will contain a couple of extra arguments.
4338   *
4339   *     @type bool         $found_avatar True if an avatar was found for this user,
4340   *                                      false or not set if none was found.
4341   *     @type string|false $url          The URL of the avatar that was found, or false.
4342   * }
4343   */
4344  function get_avatar_data( $id_or_email, $args = null ) {
4345      $args = wp_parse_args(
4346          $args,
4347          array(
4348              'size'           => 96,
4349              'height'         => null,
4350              'width'          => null,
4351              'default'        => get_option( 'avatar_default', 'mystery' ),
4352              'force_default'  => false,
4353              'rating'         => get_option( 'avatar_rating' ),
4354              'scheme'         => null,
4355              'processed_args' => null, // If used, should be a reference.
4356              'extra_attr'     => '',
4357          )
4358      );
4359  
4360      if ( is_numeric( $args['size'] ) ) {
4361          $args['size'] = absint( $args['size'] );
4362          if ( ! $args['size'] ) {
4363              $args['size'] = 96;
4364          }
4365      } else {
4366          $args['size'] = 96;
4367      }
4368  
4369      if ( is_numeric( $args['height'] ) ) {
4370          $args['height'] = absint( $args['height'] );
4371          if ( ! $args['height'] ) {
4372              $args['height'] = $args['size'];
4373          }
4374      } else {
4375          $args['height'] = $args['size'];
4376      }
4377  
4378      if ( is_numeric( $args['width'] ) ) {
4379          $args['width'] = absint( $args['width'] );
4380          if ( ! $args['width'] ) {
4381              $args['width'] = $args['size'];
4382          }
4383      } else {
4384          $args['width'] = $args['size'];
4385      }
4386  
4387      if ( empty( $args['default'] ) ) {
4388          $args['default'] = get_option( 'avatar_default', 'mystery' );
4389      }
4390  
4391      switch ( $args['default'] ) {
4392          case 'mm':
4393          case 'mystery':
4394          case 'mysteryman':
4395              $args['default'] = 'mm';
4396              break;
4397          case 'gravatar_default':
4398              $args['default'] = false;
4399              break;
4400      }
4401  
4402      $args['force_default'] = (bool) $args['force_default'];
4403  
4404      $args['rating'] = strtolower( $args['rating'] );
4405  
4406      $args['found_avatar'] = false;
4407  
4408      /**
4409       * Filters whether to retrieve the avatar URL early.
4410       *
4411       * Passing a non-null value in the 'url' member of the return array will
4412       * effectively short circuit get_avatar_data(), passing the value through
4413       * the {@see 'get_avatar_data'} filter and returning early.
4414       *
4415       * @since 4.2.0
4416       *
4417       * @param array $args        Arguments passed to get_avatar_data(), after processing.
4418       * @param mixed $id_or_email The avatar to retrieve. Accepts a user ID, Gravatar MD5 hash,
4419       *                           user email, WP_User object, WP_Post object, or WP_Comment object.
4420       */
4421      $args = apply_filters( 'pre_get_avatar_data', $args, $id_or_email );
4422  
4423      if ( isset( $args['url'] ) ) {
4424          /** This filter is documented in wp-includes/link-template.php */
4425          return apply_filters( 'get_avatar_data', $args, $id_or_email );
4426      }
4427  
4428      $email_hash = '';
4429      $user       = false;
4430      $email      = false;
4431  
4432      if ( is_object( $id_or_email ) && isset( $id_or_email->comment_ID ) ) {
4433          $id_or_email = get_comment( $id_or_email );
4434      }
4435  
4436      // Process the user identifier.
4437      if ( is_numeric( $id_or_email ) ) {
4438          $user = get_user_by( 'id', absint( $id_or_email ) );
4439      } elseif ( is_string( $id_or_email ) ) {
4440          if ( str_contains( $id_or_email, '@md5.gravatar.com' ) ) {
4441              // MD5 hash.
4442              list( $email_hash ) = explode( '@', $id_or_email );
4443          } else {
4444              // Email address.
4445              $email = $id_or_email;
4446          }
4447      } elseif ( $id_or_email instanceof WP_User ) {
4448          // User object.
4449          $user = $id_or_email;
4450      } elseif ( $id_or_email instanceof WP_Post ) {
4451          // Post object.
4452          $user = get_user_by( 'id', (int) $id_or_email->post_author );
4453      } elseif ( $id_or_email instanceof WP_Comment ) {
4454          if ( ! is_avatar_comment_type( get_comment_type( $id_or_email ) ) ) {
4455              $args['url'] = false;
4456              /** This filter is documented in wp-includes/link-template.php */
4457              return apply_filters( 'get_avatar_data', $args, $id_or_email );
4458          }
4459  
4460          if ( ! empty( $id_or_email->user_id ) ) {
4461              $user = get_user_by( 'id', (int) $id_or_email->user_id );
4462          }
4463          if ( ( ! $user || is_wp_error( $user ) ) && ! empty( $id_or_email->comment_author_email ) ) {
4464              $email = $id_or_email->comment_author_email;
4465          }
4466      }
4467  
4468      if ( ! $email_hash ) {
4469          if ( $user ) {
4470              $email = $user->user_email;
4471          }
4472  
4473          if ( $email ) {
4474              $email_hash = md5( strtolower( trim( $email ) ) );
4475          }
4476      }
4477  
4478      if ( $email_hash ) {
4479          $args['found_avatar'] = true;
4480          $gravatar_server      = hexdec( $email_hash[0] ) % 3;
4481      } else {
4482          $gravatar_server = rand( 0, 2 );
4483      }
4484  
4485      $url_args = array(
4486          's' => $args['size'],
4487          'd' => $args['default'],
4488          'f' => $args['force_default'] ? 'y' : false,
4489          'r' => $args['rating'],
4490      );
4491  
4492      if ( is_ssl() ) {
4493          $url = 'https://secure.gravatar.com/avatar/' . $email_hash;
4494      } else {
4495          $url = sprintf( 'http://%d.gravatar.com/avatar/%s', $gravatar_server, $email_hash );
4496      }
4497  
4498      $url = add_query_arg(
4499          rawurlencode_deep( array_filter( $url_args ) ),
4500          set_url_scheme( $url, $args['scheme'] )
4501      );
4502  
4503      /**
4504       * Filters the avatar URL.
4505       *
4506       * @since 4.2.0
4507       *
4508       * @param string $url         The URL of the avatar.
4509       * @param mixed  $id_or_email The avatar to retrieve. Accepts a user ID, Gravatar MD5 hash,
4510       *                            user email, WP_User object, WP_Post object, or WP_Comment object.
4511       * @param array  $args        Arguments passed to get_avatar_data(), after processing.
4512       */
4513      $args['url'] = apply_filters( 'get_avatar_url', $url, $id_or_email, $args );
4514  
4515      /**
4516       * Filters the avatar data.
4517       *
4518       * @since 4.2.0
4519       *
4520       * @param array $args        Arguments passed to get_avatar_data(), after processing.
4521       * @param mixed $id_or_email The avatar to retrieve. Accepts a user ID, Gravatar MD5 hash,
4522       *                           user email, WP_User object, WP_Post object, or WP_Comment object.
4523       */
4524      return apply_filters( 'get_avatar_data', $args, $id_or_email );
4525  }
4526  
4527  /**
4528   * Retrieves the URL of a file in the theme.
4529   *
4530   * Searches in the stylesheet directory before the template directory so themes
4531   * which inherit from a parent theme can just override one file.
4532   *
4533   * @since 4.7.0
4534   *
4535   * @param string $file Optional. File to search for in the stylesheet directory.
4536   * @return string The URL of the file.
4537   */
4538  function get_theme_file_uri( $file = '' ) {
4539      $file = ltrim( $file, '/' );
4540  
4541      $stylesheet_directory = get_stylesheet_directory();
4542  
4543      if ( empty( $file ) ) {
4544          $url = get_stylesheet_directory_uri();
4545      } elseif ( get_template_directory() !== $stylesheet_directory && file_exists( $stylesheet_directory . '/' . $file ) ) {
4546          $url = get_stylesheet_directory_uri() . '/' . $file;
4547      } else {
4548          $url = get_template_directory_uri() . '/' . $file;
4549      }
4550  
4551      /**
4552       * Filters the URL to a file in the theme.
4553       *
4554       * @since 4.7.0
4555       *
4556       * @param string $url  The file URL.
4557       * @param string $file The requested file to search for.
4558       */
4559      return apply_filters( 'theme_file_uri', $url, $file );
4560  }
4561  
4562  /**
4563   * Retrieves the URL of a file in the parent theme.
4564   *
4565   * @since 4.7.0
4566   *
4567   * @param string $file Optional. File to return the URL for in the template directory.
4568   * @return string The URL of the file.
4569   */
4570  function get_parent_theme_file_uri( $file = '' ) {
4571      $file = ltrim( $file, '/' );
4572  
4573      if ( empty( $file ) ) {
4574          $url = get_template_directory_uri();
4575      } else {
4576          $url = get_template_directory_uri() . '/' . $file;
4577      }
4578  
4579      /**
4580       * Filters the URL to a file in the parent theme.
4581       *
4582       * @since 4.7.0
4583       *
4584       * @param string $url  The file URL.
4585       * @param string $file The requested file to search for.
4586       */
4587      return apply_filters( 'parent_theme_file_uri', $url, $file );
4588  }
4589  
4590  /**
4591   * Retrieves the path of a file in the theme.
4592   *
4593   * Searches in the stylesheet directory before the template directory so themes
4594   * which inherit from a parent theme can just override one file.
4595   *
4596   * @since 4.7.0
4597   *
4598   * @param string $file Optional. File to search for in the stylesheet directory.
4599   * @return string The path of the file.
4600   */
4601  function get_theme_file_path( $file = '' ) {
4602      $file = ltrim( $file, '/' );
4603  
4604      $stylesheet_directory = get_stylesheet_directory();
4605      $template_directory   = get_template_directory();
4606  
4607      if ( empty( $file ) ) {
4608          $path = $stylesheet_directory;
4609      } elseif ( $stylesheet_directory !== $template_directory && file_exists( $stylesheet_directory . '/' . $file ) ) {
4610          $path = $stylesheet_directory . '/' . $file;
4611      } else {
4612          $path = $template_directory . '/' . $file;
4613      }
4614  
4615      /**
4616       * Filters the path to a file in the theme.
4617       *
4618       * @since 4.7.0
4619       *
4620       * @param string $path The file path.
4621       * @param string $file The requested file to search for.
4622       */
4623      return apply_filters( 'theme_file_path', $path, $file );
4624  }
4625  
4626  /**
4627   * Retrieves the path of a file in the parent theme.
4628   *
4629   * @since 4.7.0
4630   *
4631   * @param string $file Optional. File to return the path for in the template directory.
4632   * @return string The path of the file.
4633   */
4634  function get_parent_theme_file_path( $file = '' ) {
4635      $file = ltrim( $file, '/' );
4636  
4637      if ( empty( $file ) ) {
4638          $path = get_template_directory();
4639      } else {
4640          $path = get_template_directory() . '/' . $file;
4641      }
4642  
4643      /**
4644       * Filters the path to a file in the parent theme.
4645       *
4646       * @since 4.7.0
4647       *
4648       * @param string $path The file path.
4649       * @param string $file The requested file to search for.
4650       */
4651      return apply_filters( 'parent_theme_file_path', $path, $file );
4652  }
4653  
4654  /**
4655   * Retrieves the URL to the privacy policy page.
4656   *
4657   * @since 4.9.6
4658   *
4659   * @return string The URL to the privacy policy page. Empty string if it doesn't exist.
4660   */
4661  function get_privacy_policy_url() {
4662      $url            = '';
4663      $policy_page_id = (int) get_option( 'wp_page_for_privacy_policy' );
4664  
4665      if ( ! empty( $policy_page_id ) && get_post_status( $policy_page_id ) === 'publish' ) {
4666          $url = (string) get_permalink( $policy_page_id );
4667      }
4668  
4669      /**
4670       * Filters the URL of the privacy policy page.
4671       *
4672       * @since 4.9.6
4673       *
4674       * @param string $url            The URL to the privacy policy page. Empty string
4675       *                               if it doesn't exist.
4676       * @param int    $policy_page_id The ID of privacy policy page.
4677       */
4678      return apply_filters( 'privacy_policy_url', $url, $policy_page_id );
4679  }
4680  
4681  /**
4682   * Displays the privacy policy link with formatting, when applicable.
4683   *
4684   * @since 4.9.6
4685   *
4686   * @param string $before Optional. Display before privacy policy link. Default empty.
4687   * @param string $after  Optional. Display after privacy policy link. Default empty.
4688   */
4689  function the_privacy_policy_link( $before = '', $after = '' ) {
4690      echo get_the_privacy_policy_link( $before, $after );
4691  }
4692  
4693  /**
4694   * Returns the privacy policy link with formatting, when applicable.
4695   *
4696   * @since 4.9.6
4697   * @since 6.2.0 Added 'privacy-policy' rel attribute.
4698   *
4699   * @param string $before Optional. Display before privacy policy link. Default empty.
4700   * @param string $after  Optional. Display after privacy policy link. Default empty.
4701   * @return string Markup for the link and surrounding elements. Empty string if it
4702   *                doesn't exist.
4703   */
4704  function get_the_privacy_policy_link( $before = '', $after = '' ) {
4705      $link               = '';
4706      $privacy_policy_url = get_privacy_policy_url();
4707      $policy_page_id     = (int) get_option( 'wp_page_for_privacy_policy' );
4708      $page_title         = ( $policy_page_id ) ? get_the_title( $policy_page_id ) : '';
4709  
4710      if ( $privacy_policy_url && $page_title ) {
4711          $link = sprintf(
4712              '<a class="privacy-policy-link" href="%s" rel="privacy-policy">%s</a>',
4713              esc_url( $privacy_policy_url ),
4714              esc_html( $page_title )
4715          );
4716      }
4717  
4718      /**
4719       * Filters the privacy policy link.
4720       *
4721       * @since 4.9.6
4722       *
4723       * @param string $link               The privacy policy link. Empty string if it
4724       *                                   doesn't exist.
4725       * @param string $privacy_policy_url The URL of the privacy policy. Empty string
4726       *                                   if it doesn't exist.
4727       */
4728      $link = apply_filters( 'the_privacy_policy_link', $link, $privacy_policy_url );
4729  
4730      if ( $link ) {
4731          return $before . $link . $after;
4732      }
4733  
4734      return '';
4735  }
4736  
4737  /**
4738   * Returns an array of URL hosts which are considered to be internal hosts.
4739   *
4740   * By default the list of internal hosts is comprised of the host name of
4741   * the site's home_url() (as parsed by wp_parse_url()).
4742   *
4743   * This list is used when determining if a specificed URL is a link to a page on
4744   * the site itself or a link offsite (to an external host). This is used, for
4745   * example, when determining if the "nofollow" attribute should be applied to a
4746   * link.
4747   *
4748   * @see wp_is_internal_link
4749   *
4750   * @since 6.2.0
4751   *
4752   * @return string[] An array of URL hosts.
4753   */
4754  function wp_internal_hosts() {
4755      static $internal_hosts;
4756  
4757      if ( empty( $internal_hosts ) ) {
4758          /**
4759           * Filters the array of URL hosts which are considered internal.
4760           *
4761           * @since 6.2.0
4762           *
4763           * @param string[] $internal_hosts An array of internal URL hostnames.
4764           */
4765          $internal_hosts = apply_filters(
4766              'wp_internal_hosts',
4767              array(
4768                  wp_parse_url( home_url(), PHP_URL_HOST ),
4769              )
4770          );
4771          $internal_hosts = array_unique(
4772              array_map( 'strtolower', (array) $internal_hosts )
4773          );
4774      }
4775  
4776      return $internal_hosts;
4777  }
4778  
4779  /**
4780   * Determines whether or not the specified URL is of a host included in the internal hosts list.
4781   *
4782   * @see wp_internal_hosts()
4783   *
4784   * @since 6.2.0
4785   *
4786   * @param string $link The URL to test.
4787   * @return bool Returns true for internal URLs and false for all other URLs.
4788   */
4789  function wp_is_internal_link( $link ) {
4790      $link = strtolower( $link );
4791      if ( in_array( wp_parse_url( $link, PHP_URL_SCHEME ), wp_allowed_protocols(), true ) ) {
4792          return in_array( wp_parse_url( $link, PHP_URL_HOST ), wp_internal_hosts(), true );
4793      }
4794      return false;
4795  }


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