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   1  <?php
   2  /**
   3   * WordPress API for creating bbcode like tags or what WordPress calls
   4   * "shortcodes." The tag and attribute parsing or regular expression code is
   5   * based on the Textpattern tag parser.
   6   *
   7   * A few examples are below:
   8   *
   9   * [shortcode /]
  10   * [shortcode foo="bar" baz="bing" /]
  11   * [shortcode foo="bar"]content[/shortcode]
  12   *
  13   * Shortcode tags support attributes and enclosed content, but does not entirely
  14   * support inline shortcodes in other shortcodes. You will have to call the
  15   * shortcode parser in your function to account for that.
  16   *
  17   * {@internal
  18   * Please be aware that the above note was made during the beta of WordPress 2.6
  19   * and in the future may not be accurate. Please update the note when it is no
  20   * longer the case.}}
  21   *
  22   * To apply shortcode tags to content:
  23   *
  24   * <code>
  25   * $out = do_shortcode($content);
  26   * </code>
  27   *
  28   * @link http://codex.wordpress.org/Shortcode_API
  29   *
  30   * @package WordPress
  31   * @subpackage Shortcodes
  32   * @since 2.5
  33   */
  34  
  35  /**
  36   * Container for storing shortcode tags and their hook to call for the shortcode
  37   *
  38   * @since 2.5
  39   * @name $shortcode_tags
  40   * @var array
  41   * @global array $shortcode_tags
  42   */
  43  $shortcode_tags = array();
  44  
  45  /**
  46   * Add hook for shortcode tag.
  47   *
  48   * There can only be one hook for each shortcode. Which means that if another
  49   * plugin has a similar shortcode, it will override yours or yours will override
  50   * theirs depending on which order the plugins are included and/or ran.
  51   *
  52   * Simplest example of a shortcode tag using the API:
  53   *
  54   * <code>
  55   * // [footag foo="bar"]
  56   * function footag_func($atts) {
  57   *     return "foo = {$atts[foo]}";
  58   * }
  59   * add_shortcode('footag', 'footag_func');
  60   * </code>
  61   *
  62   * Example with nice attribute defaults:
  63   *
  64   * <code>
  65   * // [bartag foo="bar"]
  66   * function bartag_func($atts) {
  67   *     extract(shortcode_atts(array(
  68   *         'foo' => 'no foo',
  69   *         'baz' => 'default baz',
  70   *     ), $atts));
  71   *
  72   *     return "foo = {$foo}";
  73   * }
  74   * add_shortcode('bartag', 'bartag_func');
  75   * </code>
  76   *
  77   * Example with enclosed content:
  78   *
  79   * <code>
  80   * // [baztag]content[/baztag]
  81   * function baztag_func($atts, $content='') {
  82   *     return "content = $content";
  83   * }
  84   * add_shortcode('baztag', 'baztag_func');
  85   * </code>
  86   *
  87   * @since 2.5
  88   * @uses $shortcode_tags
  89   *
  90   * @param string $tag Shortcode tag to be searched in post content.
  91   * @param callable $func Hook to run when shortcode is found.
  92   */
  93  function add_shortcode($tag, $func) {
  94      global $shortcode_tags;
  95  
  96      if ( is_callable($func) )
  97          $shortcode_tags[$tag] = $func;
  98  }
  99  
 100  /**
 101   * Removes hook for shortcode.
 102   *
 103   * @since 2.5
 104   * @uses $shortcode_tags
 105   *
 106   * @param string $tag shortcode tag to remove hook for.
 107   */
 108  function remove_shortcode($tag) {
 109      global $shortcode_tags;
 110  
 111      unset($shortcode_tags[$tag]);
 112  }
 113  
 114  /**
 115   * Clear all shortcodes.
 116   *
 117   * This function is simple, it clears all of the shortcode tags by replacing the
 118   * shortcodes global by a empty array. This is actually a very efficient method
 119   * for removing all shortcodes.
 120   *
 121   * @since 2.5
 122   * @uses $shortcode_tags
 123   */
 124  function remove_all_shortcodes() {
 125      global $shortcode_tags;
 126  
 127      $shortcode_tags = array();
 128  }
 129  
 130  /**
 131   * Search content for shortcodes and filter shortcodes through their hooks.
 132   *
 133   * If there are no shortcode tags defined, then the content will be returned
 134   * without any filtering. This might cause issues when plugins are disabled but
 135   * the shortcode will still show up in the post or content.
 136   *
 137   * @since 2.5
 138   * @uses $shortcode_tags
 139   * @uses get_shortcode_regex() Gets the search pattern for searching shortcodes.
 140   *
 141   * @param string $content Content to search for shortcodes
 142   * @return string Content with shortcodes filtered out.
 143   */
 144  function do_shortcode($content) {
 145      global $shortcode_tags;
 146  
 147      if (empty($shortcode_tags) || !is_array($shortcode_tags))
 148          return $content;
 149  
 150      $pattern = get_shortcode_regex();
 151      return preg_replace_callback( "/$pattern/s", 'do_shortcode_tag', $content );
 152  }
 153  
 154  /**
 155   * Retrieve the shortcode regular expression for searching.
 156   *
 157   * The regular expression combines the shortcode tags in the regular expression
 158   * in a regex class.
 159   *
 160   * The regular expression contains 6 different sub matches to help with parsing.
 161   *
 162   * 1 - An extra [ to allow for escaping shortcodes with double [[]]
 163   * 2 - The shortcode name
 164   * 3 - The shortcode argument list
 165   * 4 - The self closing /
 166   * 5 - The content of a shortcode when it wraps some content.
 167   * 6 - An extra ] to allow for escaping shortcodes with double [[]]
 168   *
 169   * @since 2.5
 170   * @uses $shortcode_tags
 171   *
 172   * @return string The shortcode search regular expression
 173   */
 174  function get_shortcode_regex() {
 175      global $shortcode_tags;
 176      $tagnames = array_keys($shortcode_tags);
 177      $tagregexp = join( '|', array_map('preg_quote', $tagnames) );
 178  
 179      // WARNING! Do not change this regex without changing do_shortcode_tag() and strip_shortcode_tag()
 180      return
 181            '\\['                              // Opening bracket
 182          . '(\\[?)'                           // 1: Optional second opening bracket for escaping shortcodes: [[tag]]
 183          . "($tagregexp)"                     // 2: Shortcode name
 184          . '\\b'                              // Word boundary
 185          . '('                                // 3: Unroll the loop: Inside the opening shortcode tag
 186          .     '[^\\]\\/]*'                   // Not a closing bracket or forward slash
 187          .     '(?:'
 188          .         '\\/(?!\\])'               // A forward slash not followed by a closing bracket
 189          .         '[^\\]\\/]*'               // Not a closing bracket or forward slash
 190          .     ')*?'
 191          . ')'
 192          . '(?:'
 193          .     '(\\/)'                        // 4: Self closing tag ...
 194          .     '\\]'                          // ... and closing bracket
 195          . '|'
 196          .     '\\]'                          // Closing bracket
 197          .     '(?:'
 198          .         '('                        // 5: Unroll the loop: Optionally, anything between the opening and closing shortcode tags
 199          .             '[^\\[]*+'             // Not an opening bracket
 200          .             '(?:'
 201          .                 '\\[(?!\\/\\2\\])' // An opening bracket not followed by the closing shortcode tag
 202          .                 '[^\\[]*+'         // Not an opening bracket
 203          .             ')*+'
 204          .         ')'
 205          .         '\\[\\/\\2\\]'             // Closing shortcode tag
 206          .     ')?'
 207          . ')'
 208          . '(\\]?)';                          // 6: Optional second closing brocket for escaping shortcodes: [[tag]]
 209  }
 210  
 211  /**
 212   * Regular Expression callable for do_shortcode() for calling shortcode hook.
 213   * @see get_shortcode_regex for details of the match array contents.
 214   *
 215   * @since 2.5
 216   * @access private
 217   * @uses $shortcode_tags
 218   *
 219   * @param array $m Regular expression match array
 220   * @return mixed False on failure.
 221   */
 222  function do_shortcode_tag( $m ) {
 223      global $shortcode_tags;
 224  
 225      // allow [[foo]] syntax for escaping a tag
 226      if ( $m[1] == '[' && $m[6] == ']' ) {
 227          return substr($m[0], 1, -1);
 228      }
 229  
 230      $tag = $m[2];
 231      $attr = shortcode_parse_atts( $m[3] );
 232  
 233      if ( isset( $m[5] ) ) {
 234          // enclosing tag - extra parameter
 235          return $m[1] . call_user_func( $shortcode_tags[$tag], $attr, $m[5], $tag ) . $m[6];
 236      } else {
 237          // self-closing tag
 238          return $m[1] . call_user_func( $shortcode_tags[$tag], $attr, null,  $tag ) . $m[6];
 239      }
 240  }
 241  
 242  /**
 243   * Retrieve all attributes from the shortcodes tag.
 244   *
 245   * The attributes list has the attribute name as the key and the value of the
 246   * attribute as the value in the key/value pair. This allows for easier
 247   * retrieval of the attributes, since all attributes have to be known.
 248   *
 249   * @since 2.5
 250   *
 251   * @param string $text
 252   * @return array List of attributes and their value.
 253   */
 254  function shortcode_parse_atts($text) {
 255      $atts = array();
 256      $pattern = '/(\w+)\s*=\s*"([^"]*)"(?:\s|$)|(\w+)\s*=\s*\'([^\']*)\'(?:\s|$)|(\w+)\s*=\s*([^\s\'"]+)(?:\s|$)|"([^"]*)"(?:\s|$)|(\S+)(?:\s|$)/';
 257      $text = preg_replace("/[\x{00a0}\x{200b}]+/u", " ", $text);
 258      if ( preg_match_all($pattern, $text, $match, PREG_SET_ORDER) ) {
 259          foreach ($match as $m) {
 260              if (!empty($m[1]))
 261                  $atts[strtolower($m[1])] = stripcslashes($m[2]);
 262              elseif (!empty($m[3]))
 263                  $atts[strtolower($m[3])] = stripcslashes($m[4]);
 264              elseif (!empty($m[5]))
 265                  $atts[strtolower($m[5])] = stripcslashes($m[6]);
 266              elseif (isset($m[7]) and strlen($m[7]))
 267                  $atts[] = stripcslashes($m[7]);
 268              elseif (isset($m[8]))
 269                  $atts[] = stripcslashes($m[8]);
 270          }
 271      } else {
 272          $atts = ltrim($text);
 273      }
 274      return $atts;
 275  }
 276  
 277  /**
 278   * Combine user attributes with known attributes and fill in defaults when needed.
 279   *
 280   * The pairs should be considered to be all of the attributes which are
 281   * supported by the caller and given as a list. The returned attributes will
 282   * only contain the attributes in the $pairs list.
 283   *
 284   * If the $atts list has unsupported attributes, then they will be ignored and
 285   * removed from the final returned list.
 286   *
 287   * @since 2.5
 288   *
 289   * @param array $pairs Entire list of supported attributes and their defaults.
 290   * @param array $atts User defined attributes in shortcode tag.
 291   * @return array Combined and filtered attribute list.
 292   */
 293  function shortcode_atts($pairs, $atts) {
 294      $atts = (array)$atts;
 295      $out = array();
 296      foreach($pairs as $name => $default) {
 297          if ( array_key_exists($name, $atts) )
 298              $out[$name] = $atts[$name];
 299          else
 300              $out[$name] = $default;
 301      }
 302      return $out;
 303  }
 304  
 305  /**
 306   * Remove all shortcode tags from the given content.
 307   *
 308   * @since 2.5
 309   * @uses $shortcode_tags
 310   *
 311   * @param string $content Content to remove shortcode tags.
 312   * @return string Content without shortcode tags.
 313   */
 314  function strip_shortcodes( $content ) {
 315      global $shortcode_tags;
 316  
 317      if (empty($shortcode_tags) || !is_array($shortcode_tags))
 318          return $content;
 319  
 320      $pattern = get_shortcode_regex();
 321  
 322      return preg_replace_callback( "/$pattern/s", 'strip_shortcode_tag', $content );
 323  }
 324  
 325  function strip_shortcode_tag( $m ) {
 326      // allow [[foo]] syntax for escaping a tag
 327      if ( $m[1] == '[' && $m[6] == ']' ) {
 328          return substr($m[0], 1, -1);
 329      }
 330  
 331      return $m[1] . $m[6];
 332  }
 333  
 334  add_filter('the_content', 'do_shortcode', 11); // AFTER wpautop()