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   1  <?php
   2  /**
   3   * Links Metas functions
   4   * @from WordPress 2.7.1
   5   */
   6  
   7  /**
   8   * Add meta data field to a link.
   9   *
  10   * link meta data is called "Custom Fields" on the Administration Panels.
  11   *
  12   * @since 1.5.0
  13   * @uses $wpdb
  14   * @link http://codex.wordpress.org/Function_Reference/add_link_meta
  15   *
  16   * @param int $link_id link ID.
  17   * @param string $key Metadata name.
  18   * @param mixed $value Metadata value.
  19   * @param bool $unique Optional, default is false. Whether the same key should not be added.
  20   * @return bool False for failure. True for success.
  21   */
  22  function add_link_meta($link_id, $meta_key, $meta_value, $unique = false) {
  23      global $wpdb;
  24  
  25      // expected_slashed ($meta_key)
  26      $meta_key = stripslashes($meta_key);
  27  
  28      if ( $unique && $wpdb->get_var( $wpdb->prepare( "SELECT meta_key FROM $wpdb->linkmeta WHERE meta_key = %s AND link_id = %d", $meta_key, $link_id ) ) )
  29          return false;
  30  
  31      $meta_value = maybe_serialize( stripslashes_deep($meta_value) );
  32  
  33      $wpdb->insert( $wpdb->linkmeta, compact( 'link_id', 'meta_key', 'meta_value' ) );
  34  
  35      wp_cache_delete($link_id, 'link_meta');
  36  
  37      return true;
  38  }
  39  
  40  /**
  41   * Remove metadata matching criteria from a link.
  42   *
  43   * You can match based on the key, or key and value. Removing based on key and
  44   * value, will keep from removing duplicate metadata with the same key. It also
  45   * allows removing all metadata matching key, if needed.
  46   *
  47   * @since 1.5.0
  48   * @uses $wpdb
  49   * @link http://codex.wordpress.org/Function_Reference/delete_link_meta
  50   *
  51   * @param int $link_id link ID
  52   * @param string $meta_key Metadata name.
  53   * @param mixed $meta_value Optional. Metadata value.
  54   * @return bool False for failure. True for success.
  55   */
  56  function delete_link_meta($link_id, $meta_key, $meta_value = '') {
  57      global $wpdb;
  58  
  59      // expected_slashed ($meta_key, $meta_value)
  60      $meta_key = stripslashes( $meta_key );
  61      $meta_value = maybe_serialize( stripslashes_deep($meta_value) );
  62  
  63      if ( empty( $meta_value ) )
  64          $meta_id = $wpdb->get_var( $wpdb->prepare( "SELECT meta_id FROM $wpdb->linkmeta WHERE link_id = %d AND meta_key = %s", $link_id, $meta_key ) );
  65      else
  66          $meta_id = $wpdb->get_var( $wpdb->prepare( "SELECT meta_id FROM $wpdb->linkmeta WHERE link_id = %d AND meta_key = %s AND meta_value = %s", $link_id, $meta_key, $meta_value ) );
  67  
  68      if ( !$meta_id )
  69          return false;
  70  
  71      if ( empty( $meta_value ) )
  72          $wpdb->query( $wpdb->prepare( "DELETE FROM $wpdb->linkmeta WHERE link_id = %d AND meta_key = %s", $link_id, $meta_key ) );
  73      else
  74          $wpdb->query( $wpdb->prepare( "DELETE FROM $wpdb->linkmeta WHERE link_id = %d AND meta_key = %s AND meta_value = %s", $link_id, $meta_key, $meta_value ) );
  75  
  76      wp_cache_delete($link_id, 'link_meta');
  77  
  78      return true;
  79  }
  80  
  81  /**
  82   * Retrieve link meta field for a link.
  83   *
  84   * @since 1.5.0
  85   * @uses $wpdb
  86   * @link http://codex.wordpress.org/Function_Reference/get_link_meta
  87   *
  88   * @param int $link_id link ID.
  89   * @param string $key The meta key to retrieve.
  90   * @param bool $single Whether to return a single value.
  91   * @return mixed Will be an array if $single is false. Will be value of meta data field if $single is true.
  92   */
  93  function get_link_meta($link_id, $key, $single = false) {
  94      $link_id = (int) $link_id;
  95  
  96      $meta_cache = wp_cache_get($link_id, 'link_meta');
  97  
  98      if ( !$meta_cache ) {
  99          update_linkmeta_cache($link_id);
 100          $meta_cache = wp_cache_get($link_id, 'link_meta');
 101      }
 102  
 103      if ( isset($meta_cache[$key]) ) {
 104          if ( $single ) {
 105              return maybe_unserialize( $meta_cache[$key][0] );
 106          } else {
 107              return array_map('maybe_unserialize', $meta_cache[$key]);
 108          }
 109      }
 110  
 111      return '';
 112  }
 113  
 114  /**
 115   * Update link meta field based on link ID.
 116   *
 117   * Use the $prev_value parameter to differentiate between meta fields with the
 118   * same key and link ID.
 119   *
 120   * If the meta field for the link does not exist, it will be added.
 121   *
 122   * @since 1.5
 123   * @uses $wpdb
 124   * @link http://codex.wordpress.org/Function_Reference/update_link_meta
 125   *
 126   * @param int $link_id link ID.
 127   * @param string $key Metadata key.
 128   * @param mixed $value Metadata value.
 129   * @param mixed $prev_value Optional. Previous value to check before removing.
 130   * @return bool False on failure, true if success.
 131   */
 132  function update_link_meta($link_id, $meta_key, $meta_value, $prev_value = '') {
 133      global $wpdb;
 134  
 135      // expected_slashed ($meta_key)
 136      $meta_key = stripslashes($meta_key);
 137  
 138      if ( ! $wpdb->get_var( $wpdb->prepare( "SELECT meta_key FROM $wpdb->linkmeta WHERE meta_key = %s AND link_id = %d", $meta_key, $link_id ) ) ) {
 139          return add_link_meta($link_id, $meta_key, $meta_value);
 140      }
 141  
 142      $meta_value = maybe_serialize( stripslashes_deep($meta_value) );
 143  
 144      $data  = compact( 'meta_value' );
 145      $where = compact( 'meta_key', 'link_id' );
 146  
 147      if ( !empty( $prev_value ) ) {
 148          $prev_value = maybe_serialize($prev_value);
 149          $where['meta_value'] = $prev_value;
 150      }
 151  
 152      $wpdb->update( $wpdb->linkmeta, $data, $where );
 153      wp_cache_delete($link_id, 'link_meta');
 154      return true;
 155  }
 156  
 157  /**
 158   * Delete everything from link meta matching meta key.
 159   *
 160   * @since 2.3.0
 161   * @uses $wpdb
 162   *
 163   * @param string $link_meta_key Key to search for when deleting.
 164   * @return bool Whether the link meta key was deleted from the database
 165   */
 166  function delete_link_meta_by_key($link_meta_key) {
 167      global $wpdb;
 168      if ( $wpdb->query($wpdb->prepare("DELETE FROM $wpdb->linkmeta WHERE meta_key = %s", $link_meta_key)) ) {
 169          /** @todo Get link_ids and delete cache */
 170          // wp_cache_delete($link_id, 'link_meta');
 171          return true;
 172      }
 173      return false;
 174  }
 175  
 176  /**
 177   * Retrieve link meta fields, based on link ID.
 178   *
 179   * The link meta fields are retrieved from the cache, so the function is
 180   * optimized to be called more than once. It also applies to the functions, that
 181   * use this function.
 182   *
 183   * @since 1.2.0
 184   * @link http://codex.wordpress.org/Function_Reference/get_link_custom
 185   *
 186   * @uses $link_id Current Loop link ID
 187   *
 188   * @param int $link_id link ID
 189   * @return array
 190   */
 191  function get_link_custom($link_id = 0) {
 192      global $link_id;
 193  
 194      if ( !$link_id )
 195          $link_id = (int) $link_id;
 196  
 197      $link_id = (int) $link_id;
 198  
 199      if ( ! wp_cache_get($link_id, 'link_meta') )
 200          update_linkmeta_cache($link_id);
 201  
 202      return wp_cache_get($link_id, 'link_meta');
 203  }
 204  
 205  
 206  /**
 207   * Retrieve meta field names for a link.
 208   *
 209   * If there are no meta fields, then nothing (null) will be returned.
 210   *
 211   * @since 1.2.0
 212   * @link http://codex.wordpress.org/Function_Reference/get_link_custom_keys
 213   *
 214   * @param int $link_id link ID
 215   * @return array|null Either array of the keys, or null if keys could not be retrieved.
 216   */
 217  function get_link_custom_keys( $link_id = 0 ) {
 218      $custom = get_link_custom( $link_id );
 219  
 220      if ( !is_array($custom) )
 221          return;
 222  
 223      if ( $keys = array_keys($custom) )
 224          return $keys;
 225  }
 226  
 227  /**
 228   * Retrieve values for a custom link field.
 229   *
 230   * The parameters must not be considered optional. All of the link meta fields
 231   * will be retrieved and only the meta field key values returned.
 232   *
 233   * @since 1.2.0
 234   * @link http://codex.wordpress.org/Function_Reference/get_link_custom_values
 235   *
 236   * @param string $key Meta field key.
 237   * @param int $link_id link ID
 238   * @return array Meta field values.
 239   */
 240  function get_link_custom_values( $key = '', $link_id = 0 ) {
 241      $custom = get_link_custom($link_id);
 242  
 243      return isset($custom[$key]) ? $custom[$key] : null;
 244  }
 245  
 246  
 247  /**
 248   * Updates metadata cache for list of link IDs.
 249   *
 250   * Performs SQL query to retrieve the metadata for the link IDs and updates the
 251   * metadata cache for the links. Therefore, the functions, which call this
 252   * function, do not need to perform SQL queries on their own.
 253   *
 254   * @package WordPress
 255   * @subpackage Cache
 256   * @since 2.1.0
 257   *
 258   * @uses $wpdb
 259   *
 260   * @param array $link_ids List of link IDs.
 261   * @return bool|array Returns false if there is nothing to update or an array of metadata.
 262   */
 263  function update_linkmeta_cache($link_ids) {
 264      global $wpdb;
 265  
 266      if ( empty( $link_ids ) )
 267          return false;
 268  
 269      if ( !is_array($link_ids) ) {
 270          $link_ids = preg_replace('|[^0-9,]|', '', $link_ids);
 271          $link_ids = explode(',', $link_ids);
 272      }
 273  
 274      $link_ids = array_map('intval', $link_ids);
 275  
 276      $ids = array();
 277      foreach ( (array) $link_ids as $id ) {
 278          if ( false === wp_cache_get($id, 'link_meta') )
 279              $ids[] = $id;
 280      }
 281  
 282      if ( empty( $ids ) )
 283          return false;
 284  
 285      // Get link-meta info
 286      $id_list = join(',', $ids);
 287      $cache = array();
 288      if ( $meta_list = $wpdb->get_results("SELECT link_id, meta_key, meta_value FROM $wpdb->linkmeta WHERE link_id IN ($id_list)", ARRAY_A) ) {
 289          foreach ( (array) $meta_list as $metarow) {
 290              $mpid = (int) $metarow['link_id'];
 291              $mkey = $metarow['meta_key'];
 292              $mval = $metarow['meta_value'];
 293  
 294              // Force subkeys to be array type:
 295              if ( !isset($cache[$mpid]) || !is_array($cache[$mpid]) )
 296                  $cache[$mpid] = array();
 297              if ( !isset($cache[$mpid][$mkey]) || !is_array($cache[$mpid][$mkey]) )
 298                  $cache[$mpid][$mkey] = array();
 299  
 300              // Add a value to the current pid/key:
 301              $cache[$mpid][$mkey][] = $mval;
 302          }
 303      }
 304  
 305      foreach ( (array) $ids as $id ) {
 306          if ( ! isset($cache[$id]) )
 307              $cache[$id] = array();
 308      }
 309  
 310      foreach ( (array) array_keys($cache) as $link)
 311          wp_cache_set($link, $cache[$link], 'link_meta');
 312  
 313      return $cache;
 314  }
 315  
 316