[ Index ]

PHP Cross Reference of WordPress Trunk (Updated Daily)

title

Body

[close]

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

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


Generated: Mon Jun 17 08:20:02 2019 Cross-referenced by PHPXref 0.7