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/wp-includes/ -> meta.php (source)

   1  <?php
   2  /**
   3   * Metadata API
   4   *
   5   * Functions for retrieving and manipulating metadata of various WordPress object types. Metadata
   6   * for an object is a represented by a simple key-value pair. Objects may contain multiple
   7   * metadata entries that share the same key and differ only in their value.
   8   *
   9   * @package WordPress
  10   * @subpackage Meta
  11   * @since 2.9.0
  12   */
  13  
  14  /**
  15   * Add metadata for the specified object.
  16   *
  17   * @since 2.9.0
  18   * @uses $wpdb WordPress database object for queries.
  19   * @uses do_action() Calls 'added_{$meta_type}_meta' with meta_id of added metadata entry,
  20   *         object ID, meta key, and meta value
  21   *
  22   * @param string $meta_type Type of object metadata is for (e.g., comment, post, or user)
  23   * @param int $object_id ID of the object metadata is for
  24   * @param string $meta_key Metadata key
  25   * @param string $meta_value Metadata value
  26   * @param bool $unique Optional, default is false. Whether the specified metadata key should be
  27   *         unique for the object. If true, and the object already has a value for the specified
  28   *         metadata key, no change will be made
  29   * @return bool The meta ID on successful update, false on failure.
  30   */
  31  function add_metadata($meta_type, $object_id, $meta_key, $meta_value, $unique = false) {
  32      if ( !$meta_type || !$meta_key )
  33          return false;
  34  
  35      if ( !$object_id = absint($object_id) )
  36          return false;
  37  
  38      if ( ! $table = _get_meta_table($meta_type) )
  39          return false;
  40  
  41      global $wpdb;
  42  
  43      $column = esc_sql($meta_type . '_id');
  44  
  45      // expected_slashed ($meta_key)
  46      $meta_key = stripslashes($meta_key);
  47      $meta_value = stripslashes_deep($meta_value);
  48      $meta_value = sanitize_meta( $meta_key, $meta_value, $meta_type );
  49  
  50      $check = apply_filters( "add_{$meta_type}_metadata", null, $object_id, $meta_key, $meta_value, $unique );
  51      if ( null !== $check )
  52          return $check;
  53  
  54      if ( $unique && $wpdb->get_var( $wpdb->prepare(
  55          "SELECT COUNT(*) FROM $table WHERE meta_key = %s AND $column = %d",
  56          $meta_key, $object_id ) ) )
  57          return false;
  58  
  59      $_meta_value = $meta_value;
  60      $meta_value = maybe_serialize( $meta_value );
  61  
  62      do_action( "add_{$meta_type}_meta", $object_id, $meta_key, $_meta_value );
  63  
  64      $result = $wpdb->insert( $table, array(
  65          $column => $object_id,
  66          'meta_key' => $meta_key,
  67          'meta_value' => $meta_value
  68      ) );
  69  
  70      if ( ! $result )
  71          return false;
  72  
  73      $mid = (int) $wpdb->insert_id;
  74  
  75      wp_cache_delete($object_id, $meta_type . '_meta');
  76  
  77      do_action( "added_{$meta_type}_meta", $mid, $object_id, $meta_key, $_meta_value );
  78  
  79      return $mid;
  80  }
  81  
  82  /**
  83   * Update metadata for the specified object. If no value already exists for the specified object
  84   * ID and metadata key, the metadata will be added.
  85   *
  86   * @since 2.9.0
  87   * @uses $wpdb WordPress database object for queries.
  88   * @uses do_action() Calls 'update_{$meta_type}_meta' before updating metadata with meta_id of
  89   *         metadata entry to update, object ID, meta key, and meta value
  90   * @uses do_action() Calls 'updated_{$meta_type}_meta' after updating metadata with meta_id of
  91   *         updated metadata entry, object ID, meta key, and meta value
  92   *
  93   * @param string $meta_type Type of object metadata is for (e.g., comment, post, or user)
  94   * @param int $object_id ID of the object metadata is for
  95   * @param string $meta_key Metadata key
  96   * @param string $meta_value Metadata value
  97   * @param string $prev_value Optional. If specified, only update existing metadata entries with
  98   *         the specified value. Otherwise, update all entries.
  99   * @return bool True on successful update, false on failure.
 100   */
 101  function update_metadata($meta_type, $object_id, $meta_key, $meta_value, $prev_value = '') {
 102      if ( !$meta_type || !$meta_key )
 103          return false;
 104  
 105      if ( !$object_id = absint($object_id) )
 106          return false;
 107  
 108      if ( ! $table = _get_meta_table($meta_type) )
 109          return false;
 110  
 111      global $wpdb;
 112  
 113      $column = esc_sql($meta_type . '_id');
 114      $id_column = 'user' == $meta_type ? 'umeta_id' : 'meta_id';
 115  
 116      // expected_slashed ($meta_key)
 117      $meta_key = stripslashes($meta_key);
 118      $passed_value = $meta_value;
 119      $meta_value = stripslashes_deep($meta_value);
 120      $meta_value = sanitize_meta( $meta_key, $meta_value, $meta_type );
 121  
 122      $check = apply_filters( "update_{$meta_type}_metadata", null, $object_id, $meta_key, $meta_value, $prev_value );
 123      if ( null !== $check )
 124          return (bool) $check;
 125  
 126      if ( ! $meta_id = $wpdb->get_var( $wpdb->prepare( "SELECT $id_column FROM $table WHERE meta_key = %s AND $column = %d", $meta_key, $object_id ) ) )
 127          return add_metadata($meta_type, $object_id, $meta_key, $passed_value);
 128  
 129      // Compare existing value to new value if no prev value given and the key exists only once.
 130      if ( empty($prev_value) ) {
 131          $old_value = get_metadata($meta_type, $object_id, $meta_key);
 132          if ( count($old_value) == 1 ) {
 133              if ( $old_value[0] === $meta_value )
 134                  return false;
 135          }
 136      }
 137  
 138      $_meta_value = $meta_value;
 139      $meta_value = maybe_serialize( $meta_value );
 140  
 141      $data  = compact( 'meta_value' );
 142      $where = array( $column => $object_id, 'meta_key' => $meta_key );
 143  
 144      if ( !empty( $prev_value ) ) {
 145          $prev_value = maybe_serialize($prev_value);
 146          $where['meta_value'] = $prev_value;
 147      }
 148  
 149      do_action( "update_{$meta_type}_meta", $meta_id, $object_id, $meta_key, $_meta_value );
 150  
 151      if ( 'post' == $meta_type )
 152          do_action( 'update_postmeta', $meta_id, $object_id, $meta_key, $meta_value );
 153  
 154      $wpdb->update( $table, $data, $where );
 155  
 156      wp_cache_delete($object_id, $meta_type . '_meta');
 157  
 158      do_action( "updated_{$meta_type}_meta", $meta_id, $object_id, $meta_key, $_meta_value );
 159  
 160      if ( 'post' == $meta_type )
 161          do_action( 'updated_postmeta', $meta_id, $object_id, $meta_key, $meta_value );
 162  
 163      return true;
 164  }
 165  
 166  /**
 167   * Delete metadata for the specified object.
 168   *
 169   * @since 2.9.0
 170   * @uses $wpdb WordPress database object for queries.
 171   * @uses do_action() Calls 'deleted_{$meta_type}_meta' after deleting with meta_id of
 172   *         deleted metadata entries, object ID, meta key, and meta value
 173   *
 174   * @param string $meta_type Type of object metadata is for (e.g., comment, post, or user)
 175   * @param int $object_id ID of the object metadata is for
 176   * @param string $meta_key Metadata key
 177   * @param string $meta_value Optional. Metadata value. If specified, only delete metadata entries
 178   *         with this value. Otherwise, delete all entries with the specified meta_key.
 179   * @param bool $delete_all Optional, default is false. If true, delete matching metadata entries
 180   *         for all objects, ignoring the specified object_id. Otherwise, only delete matching
 181   *         metadata entries for the specified object_id.
 182   * @return bool True on successful delete, false on failure.
 183   */
 184  function delete_metadata($meta_type, $object_id, $meta_key, $meta_value = '', $delete_all = false) {
 185      if ( !$meta_type || !$meta_key )
 186          return false;
 187  
 188      if ( (!$object_id = absint($object_id)) && !$delete_all )
 189          return false;
 190  
 191      if ( ! $table = _get_meta_table($meta_type) )
 192          return false;
 193  
 194      global $wpdb;
 195  
 196      $type_column = esc_sql($meta_type . '_id');
 197      $id_column = 'user' == $meta_type ? 'umeta_id' : 'meta_id';
 198      // expected_slashed ($meta_key)
 199      $meta_key = stripslashes($meta_key);
 200      $meta_value = stripslashes_deep($meta_value);
 201  
 202      $check = apply_filters( "delete_{$meta_type}_metadata", null, $object_id, $meta_key, $meta_value, $delete_all );
 203      if ( null !== $check )
 204          return (bool) $check;
 205  
 206      $_meta_value = $meta_value;
 207      $meta_value = maybe_serialize( $meta_value );
 208  
 209      $query = $wpdb->prepare( "SELECT $id_column FROM $table WHERE meta_key = %s", $meta_key );
 210  
 211      if ( !$delete_all )
 212          $query .= $wpdb->prepare(" AND $type_column = %d", $object_id );
 213  
 214      if ( $meta_value )
 215          $query .= $wpdb->prepare(" AND meta_value = %s", $meta_value );
 216  
 217      $meta_ids = $wpdb->get_col( $query );
 218      if ( !count( $meta_ids ) )
 219          return false;
 220  
 221      if ( $delete_all )
 222          $object_ids = $wpdb->get_col( $wpdb->prepare( "SELECT $type_column FROM $table WHERE meta_key = %s", $meta_key ) );
 223  
 224      do_action( "delete_{$meta_type}_meta", $meta_ids, $object_id, $meta_key, $_meta_value );
 225  
 226      if ( 'post' == $meta_type )
 227          do_action( 'delete_postmeta', $meta_ids );
 228  
 229      $query = "DELETE FROM $table WHERE $id_column IN( " . implode( ',', $meta_ids ) . " )";
 230  
 231      $count = $wpdb->query($query);
 232  
 233      if ( !$count )
 234          return false;
 235  
 236      if ( $delete_all ) {
 237          foreach ( (array) $object_ids as $o_id ) {
 238              wp_cache_delete($o_id, $meta_type . '_meta');
 239          }
 240      } else {
 241          wp_cache_delete($object_id, $meta_type . '_meta');
 242      }
 243  
 244      do_action( "deleted_{$meta_type}_meta", $meta_ids, $object_id, $meta_key, $_meta_value );
 245  
 246      if ( 'post' == $meta_type )
 247          do_action( 'deleted_postmeta', $meta_ids );
 248  
 249      return true;
 250  }
 251  
 252  /**
 253   * Retrieve metadata for the specified object.
 254   *
 255   * @since 2.9.0
 256   *
 257   * @param string $meta_type Type of object metadata is for (e.g., comment, post, or user)
 258   * @param int $object_id ID of the object metadata is for
 259   * @param string $meta_key Optional. Metadata key. If not specified, retrieve all metadata for
 260   *         the specified object.
 261   * @param bool $single Optional, default is false. If true, return only the first value of the
 262   *         specified meta_key. This parameter has no effect if meta_key is not specified.
 263   * @return string|array Single metadata value, or array of values
 264   */
 265  function get_metadata($meta_type, $object_id, $meta_key = '', $single = false) {
 266      if ( !$meta_type )
 267          return false;
 268  
 269      if ( !$object_id = absint($object_id) )
 270          return false;
 271  
 272      $check = apply_filters( "get_{$meta_type}_metadata", null, $object_id, $meta_key, $single );
 273      if ( null !== $check ) {
 274          if ( $single && is_array( $check ) )
 275              return $check[0];
 276          else
 277              return $check;
 278      }
 279  
 280      $meta_cache = wp_cache_get($object_id, $meta_type . '_meta');
 281  
 282      if ( !$meta_cache ) {
 283          $meta_cache = update_meta_cache( $meta_type, array( $object_id ) );
 284          $meta_cache = $meta_cache[$object_id];
 285      }
 286  
 287      if ( !$meta_key )
 288          return $meta_cache;
 289  
 290      if ( isset($meta_cache[$meta_key]) ) {
 291          if ( $single )
 292              return maybe_unserialize( $meta_cache[$meta_key][0] );
 293          else
 294              return array_map('maybe_unserialize', $meta_cache[$meta_key]);
 295      }
 296  
 297      if ($single)
 298          return '';
 299      else
 300          return array();
 301  }
 302  
 303  /**
 304   * Determine if a meta key is set for a given object
 305   *
 306   * @since 3.3.0
 307   *
 308   * @param string $meta_type Type of object metadata is for (e.g., comment, post, or user)
 309   * @param int $object_id ID of the object metadata is for
 310   * @param string $meta_key Metadata key.
 311   * @return boolean true of the key is set, false if not.
 312   */
 313  function metadata_exists( $meta_type, $object_id, $meta_key ) {
 314      if ( ! $meta_type )
 315          return false;
 316  
 317      if ( ! $object_id = absint( $object_id ) )
 318          return false;
 319  
 320      $check = apply_filters( "get_{$meta_type}_metadata", null, $object_id, $meta_key, true );
 321      if ( null !== $check )
 322          return true;
 323  
 324      $meta_cache = wp_cache_get( $object_id, $meta_type . '_meta' );
 325  
 326      if ( !$meta_cache ) {
 327          $meta_cache = update_meta_cache( $meta_type, array( $object_id ) );
 328          $meta_cache = $meta_cache[$object_id];
 329      }
 330  
 331      if ( isset( $meta_cache[ $meta_key ] ) )
 332          return true;
 333  
 334      return false;
 335  }
 336  
 337  /**
 338   * Get meta data by meta ID
 339   *
 340   * @since 3.3.0
 341   *
 342   * @param string $meta_type Type of object metadata is for (e.g., comment, post, or user)
 343   * @param int $meta_id ID for a specific meta row
 344   * @return object Meta object or false.
 345   */
 346  function get_metadata_by_mid( $meta_type, $meta_id ) {
 347      global $wpdb;
 348  
 349      if ( ! $meta_type )
 350          return false;
 351  
 352      if ( !$meta_id = absint( $meta_id ) )
 353          return false;
 354  
 355      if ( ! $table = _get_meta_table($meta_type) )
 356          return false;
 357  
 358      $id_column = ( 'user' == $meta_type ) ? 'umeta_id' : 'meta_id';
 359  
 360      $meta = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM $table WHERE $id_column = %d", $meta_id ) );
 361  
 362      if ( empty( $meta ) )
 363          return false;
 364  
 365      if ( isset( $meta->meta_value ) )
 366          $meta->meta_value = maybe_unserialize( $meta->meta_value );
 367  
 368      return $meta;
 369  }
 370  
 371  /**
 372   * Update meta data by meta ID
 373   *
 374   * @since 3.3.0
 375   *
 376   * @uses get_metadata_by_mid() Calls get_metadata_by_mid() to fetch the meta key, value
 377   *        and object_id of the given meta_id.
 378   *
 379   * @param string $meta_type Type of object metadata is for (e.g., comment, post, or user)
 380   * @param int $meta_id ID for a specific meta row
 381   * @param string $meta_value Metadata value
 382   * @param string $meta_key Optional, you can provide a meta key to update it
 383   * @return bool True on successful update, false on failure.
 384   */
 385  function update_metadata_by_mid( $meta_type, $meta_id, $meta_value, $meta_key = false ) {
 386      global $wpdb;
 387  
 388      // Make sure everything is valid.
 389      if ( ! $meta_type )
 390          return false;
 391  
 392      if ( ! $meta_id = absint( $meta_id ) )
 393          return false;
 394  
 395      if ( ! $table = _get_meta_table( $meta_type ) )
 396          return false;
 397  
 398      $column = esc_sql($meta_type . '_id');
 399      $id_column = 'user' == $meta_type ? 'umeta_id' : 'meta_id';
 400  
 401      // Fetch the meta and go on if it's found.
 402      if ( $meta = get_metadata_by_mid( $meta_type, $meta_id ) ) {
 403          $original_key = $meta->meta_key;
 404          $original_value = $meta->meta_value;
 405          $object_id = $meta->{$column};
 406  
 407          // If a new meta_key (last parameter) was specified, change the meta key,
 408          // otherwise use the original key in the update statement.
 409          if ( false === $meta_key ) {
 410              $meta_key = $original_key;
 411          } elseif ( ! is_string( $meta_key ) ) {
 412              return false;
 413          }
 414  
 415          // Sanitize the meta
 416          $_meta_value = $meta_value;
 417          $meta_value = sanitize_meta( $meta_key, $meta_value, $meta_type );
 418          $meta_value = maybe_serialize( $meta_value );
 419  
 420          // Format the data query arguments.
 421          $data = array(
 422              'meta_key' => $meta_key,
 423              'meta_value' => $meta_value
 424          );
 425  
 426          // Format the where query arguments.
 427          $where = array();
 428          $where[$id_column] = $meta_id;
 429  
 430          do_action( "update_{$meta_type}_meta", $meta_id, $object_id, $meta_key, $_meta_value );
 431  
 432          if ( 'post' == $meta_type )
 433              do_action( 'update_postmeta', $meta_id, $object_id, $meta_key, $meta_value );
 434  
 435          // Run the update query, all fields in $data are %s, $where is a %d.
 436          $result = (bool) $wpdb->update( $table, $data, $where, '%s', '%d' );
 437  
 438          // Clear the caches.
 439          wp_cache_delete($object_id, $meta_type . '_meta');
 440  
 441          do_action( "updated_{$meta_type}_meta", $meta_id, $object_id, $meta_key, $_meta_value );
 442  
 443          if ( 'post' == $meta_type )
 444              do_action( 'updated_postmeta', $meta_id, $object_id, $meta_key, $meta_value );
 445  
 446          return $result;
 447      }
 448  
 449      // And if the meta was not found.
 450      return false;
 451  }
 452  
 453  /**
 454   * Delete meta data by meta ID
 455   *
 456   * @since 3.3.0
 457   *
 458   * @uses get_metadata_by_mid() Calls get_metadata_by_mid() to fetch the meta key, value
 459   *        and object_id of the given meta_id.
 460   *
 461   * @param string $meta_type Type of object metadata is for (e.g., comment, post, or user)
 462   * @param int $meta_id ID for a specific meta row
 463   * @return bool True on successful delete, false on failure.
 464   */
 465  function delete_metadata_by_mid( $meta_type, $meta_id ) {
 466      global $wpdb;
 467  
 468      // Make sure everything is valid.
 469      if ( ! $meta_type )
 470          return false;
 471  
 472      if ( ! $meta_id = absint( $meta_id ) )
 473          return false;
 474  
 475      if ( ! $table = _get_meta_table( $meta_type ) )
 476          return false;
 477  
 478      // object and id columns
 479      $column = esc_sql($meta_type . '_id');
 480      $id_column = 'user' == $meta_type ? 'umeta_id' : 'meta_id';
 481  
 482      // Fetch the meta and go on if it's found.
 483      if ( $meta = get_metadata_by_mid( $meta_type, $meta_id ) ) {
 484          $object_id = $meta->{$column};
 485  
 486          do_action( "delete_{$meta_type}_meta", (array) $meta_id, $object_id, $meta->meta_key, $meta->meta_value );
 487  
 488          if ( 'post' == $meta_type )
 489              do_action( 'delete_postmeta', $meta_id );
 490  
 491          // Run the query, will return true if deleted, false otherwise
 492          $result = (bool) $wpdb->query( $wpdb->prepare( "DELETE FROM $table WHERE $id_column = %d LIMIT 1;", $meta_id ) );
 493  
 494          // Clear the caches.
 495          wp_cache_delete($object_id, $meta_type . '_meta');
 496  
 497          do_action( "deleted_{$meta_type}_meta", (array) $meta_id, $object_id, $meta->meta_key, $meta->meta_value );
 498  
 499          if ( 'post' == $meta_type )
 500              do_action( 'deleted_postmeta', $meta_id );
 501  
 502          return $result;
 503  
 504      }
 505  
 506      // Meta id was not found.
 507      return false;
 508  }
 509  
 510  /**
 511   * Update the metadata cache for the specified objects.
 512   *
 513   * @since 2.9.0
 514   * @uses $wpdb WordPress database object for queries.
 515   *
 516   * @param string $meta_type Type of object metadata is for (e.g., comment, post, or user)
 517   * @param int|array $object_ids array or comma delimited list of object IDs to update cache for
 518   * @return mixed Metadata cache for the specified objects, or false on failure.
 519   */
 520  function update_meta_cache($meta_type, $object_ids) {
 521      if ( empty( $meta_type ) || empty( $object_ids ) )
 522          return false;
 523  
 524      if ( ! $table = _get_meta_table($meta_type) )
 525          return false;
 526  
 527      $column = esc_sql($meta_type . '_id');
 528  
 529      global $wpdb;
 530  
 531      if ( !is_array($object_ids) ) {
 532          $object_ids = preg_replace('|[^0-9,]|', '', $object_ids);
 533          $object_ids = explode(',', $object_ids);
 534      }
 535  
 536      $object_ids = array_map('intval', $object_ids);
 537  
 538      $cache_key = $meta_type . '_meta';
 539      $ids = array();
 540      $cache = array();
 541      foreach ( $object_ids as $id ) {
 542          $cached_object = wp_cache_get( $id, $cache_key );
 543          if ( false === $cached_object )
 544              $ids[] = $id;
 545          else
 546              $cache[$id] = $cached_object;
 547      }
 548  
 549      if ( empty( $ids ) )
 550          return $cache;
 551  
 552      // Get meta info
 553      $id_list = join(',', $ids);
 554      $meta_list = $wpdb->get_results( $wpdb->prepare("SELECT $column, meta_key, meta_value FROM $table WHERE $column IN ($id_list)",
 555          $meta_type), ARRAY_A );
 556  
 557      if ( !empty($meta_list) ) {
 558          foreach ( $meta_list as $metarow) {
 559              $mpid = intval($metarow[$column]);
 560              $mkey = $metarow['meta_key'];
 561              $mval = $metarow['meta_value'];
 562  
 563              // Force subkeys to be array type:
 564              if ( !isset($cache[$mpid]) || !is_array($cache[$mpid]) )
 565                  $cache[$mpid] = array();
 566              if ( !isset($cache[$mpid][$mkey]) || !is_array($cache[$mpid][$mkey]) )
 567                  $cache[$mpid][$mkey] = array();
 568  
 569              // Add a value to the current pid/key:
 570              $cache[$mpid][$mkey][] = $mval;
 571          }
 572      }
 573  
 574      foreach ( $ids as $id ) {
 575          if ( ! isset($cache[$id]) )
 576              $cache[$id] = array();
 577          wp_cache_add( $id, $cache[$id], $cache_key );
 578      }
 579  
 580      return $cache;
 581  }
 582  
 583  /**
 584   * Given a meta query, generates SQL clauses to be appended to a main query
 585   *
 586   * @since 3.2.0
 587   *
 588   * @see WP_Meta_Query
 589   *
 590   * @param array $meta_query A meta query
 591   * @param string $type Type of meta
 592   * @param string $primary_table
 593   * @param string $primary_id_column
 594   * @param object $context (optional) The main query object
 595   * @return array( 'join' => $join_sql, 'where' => $where_sql )
 596   */
 597  function get_meta_sql( $meta_query, $type, $primary_table, $primary_id_column, $context = null ) {
 598      $meta_query_obj = new WP_Meta_Query( $meta_query );
 599      return $meta_query_obj->get_sql( $type, $primary_table, $primary_id_column, $context );
 600  }
 601  
 602  /**
 603   * Container class for a multiple metadata query
 604   *
 605   * @since 3.2.0
 606   */
 607  class WP_Meta_Query {
 608      /**
 609      * List of metadata queries. A single query is an associative array:
 610      * - 'key' string The meta key
 611      * - 'value' string|array The meta value
 612      * - 'compare' (optional) string How to compare the key to the value.
 613      *              Possible values: '=', '!=', '>', '>=', '<', '<=', 'LIKE', 'NOT LIKE', 'IN', 'NOT IN', 'BETWEEN', 'NOT BETWEEN'.
 614      *              Default: '='
 615      * - 'type' string (optional) The type of the value.
 616      *              Possible values: 'NUMERIC', 'BINARY', 'CHAR', 'DATE', 'DATETIME', 'DECIMAL', 'SIGNED', 'TIME', 'UNSIGNED'.
 617      *              Default: 'CHAR'
 618      *
 619      * @since 3.2.0
 620      * @access public
 621      * @var array
 622      */
 623      public $queries = array();
 624  
 625      /**
 626       * The relation between the queries. Can be one of 'AND' or 'OR'.
 627       *
 628       * @since 3.2.0
 629       * @access public
 630       * @var string
 631       */
 632      public $relation;
 633  
 634      /**
 635       * Constructor
 636       *
 637       * @param array $meta_query (optional) A meta query
 638       */
 639  	function __construct( $meta_query = false ) {
 640          if ( !$meta_query )
 641              return;
 642  
 643          if ( isset( $meta_query['relation'] ) && strtoupper( $meta_query['relation'] ) == 'OR' ) {
 644              $this->relation = 'OR';
 645          } else {
 646              $this->relation = 'AND';
 647          }
 648  
 649          $this->queries = array();
 650  
 651          foreach ( $meta_query as $key => $query ) {
 652              if ( ! is_array( $query ) )
 653                  continue;
 654  
 655              $this->queries[] = $query;
 656          }
 657      }
 658  
 659      /**
 660       * Constructs a meta query based on 'meta_*' query vars
 661       *
 662       * @since 3.2.0
 663       * @access public
 664       *
 665       * @param array $qv The query variables
 666       */
 667  	function parse_query_vars( $qv ) {
 668          $meta_query = array();
 669  
 670          // Simple query needs to be first for orderby=meta_value to work correctly
 671          foreach ( array( 'key', 'compare', 'type' ) as $key ) {
 672              if ( !empty( $qv[ "meta_$key" ] ) )
 673                  $meta_query[0][ $key ] = $qv[ "meta_$key" ];
 674          }
 675  
 676          // WP_Query sets 'meta_value' = '' by default
 677          if ( isset( $qv[ 'meta_value' ] ) && '' !== $qv[ 'meta_value' ] )
 678              $meta_query[0]['value'] = $qv[ 'meta_value' ];
 679  
 680          if ( !empty( $qv['meta_query'] ) && is_array( $qv['meta_query'] ) ) {
 681              $meta_query = array_merge( $meta_query, $qv['meta_query'] );
 682          }
 683  
 684          $this->__construct( $meta_query );
 685      }
 686  
 687      /**
 688       * Generates SQL clauses to be appended to a main query.
 689       *
 690       * @since 3.2.0
 691       * @access public
 692       *
 693       * @param string $type Type of meta
 694       * @param string $primary_table
 695       * @param string $primary_id_column
 696       * @param object $context (optional) The main query object
 697       * @return array( 'join' => $join_sql, 'where' => $where_sql )
 698       */
 699  	function get_sql( $type, $primary_table, $primary_id_column, $context = null ) {
 700          global $wpdb;
 701  
 702          if ( ! $meta_table = _get_meta_table( $type ) )
 703              return false;
 704  
 705          $meta_id_column = esc_sql( $type . '_id' );
 706  
 707          $join = array();
 708          $where = array();
 709  
 710          foreach ( $this->queries as $k => $q ) {
 711              $meta_key = isset( $q['key'] ) ? trim( $q['key'] ) : '';
 712              $meta_type = isset( $q['type'] ) ? strtoupper( $q['type'] ) : 'CHAR';
 713  
 714              if ( 'NUMERIC' == $meta_type )
 715                  $meta_type = 'SIGNED';
 716              elseif ( ! in_array( $meta_type, array( 'BINARY', 'CHAR', 'DATE', 'DATETIME', 'DECIMAL', 'SIGNED', 'TIME', 'UNSIGNED' ) ) )
 717                  $meta_type = 'CHAR';
 718  
 719              $i = count( $join );
 720              $alias = $i ? 'mt' . $i : $meta_table;
 721  
 722              // Set JOIN
 723              $join[$i]  = "INNER JOIN $meta_table";
 724              $join[$i] .= $i ? " AS $alias" : '';
 725              $join[$i] .= " ON ($primary_table.$primary_id_column = $alias.$meta_id_column)";
 726  
 727              $where[$k] = '';
 728              if ( !empty( $meta_key ) )
 729                  $where[$k] = $wpdb->prepare( "$alias.meta_key = %s", $meta_key );
 730  
 731              if ( !isset( $q['value'] ) ) {
 732                  if ( empty( $where[$k] ) )
 733                      unset( $join[$i] );
 734                  continue;
 735              }
 736  
 737              $meta_value = $q['value'];
 738  
 739              $meta_compare = is_array( $meta_value ) ? 'IN' : '=';
 740              if ( isset( $q['compare'] ) )
 741                  $meta_compare = strtoupper( $q['compare'] );
 742  
 743              if ( ! in_array( $meta_compare, array( '=', '!=', '>', '>=', '<', '<=', 'LIKE', 'NOT LIKE', 'IN', 'NOT IN', 'BETWEEN', 'NOT BETWEEN' ) ) )
 744                  $meta_compare = '=';
 745  
 746              if ( in_array( $meta_compare, array( 'IN', 'NOT IN', 'BETWEEN', 'NOT BETWEEN' ) ) ) {
 747                  if ( ! is_array( $meta_value ) )
 748                      $meta_value = preg_split( '/[,\s]+/', $meta_value );
 749  
 750                  if ( empty( $meta_value ) ) {
 751                      unset( $join[$i] );
 752                      continue;
 753                  }
 754              } else {
 755                  $meta_value = trim( $meta_value );
 756              }
 757  
 758              if ( 'IN' == substr( $meta_compare, -2) ) {
 759                  $meta_compare_string = '(' . substr( str_repeat( ',%s', count( $meta_value ) ), 1 ) . ')';
 760              } elseif ( 'BETWEEN' == substr( $meta_compare, -7) ) {
 761                  $meta_value = array_slice( $meta_value, 0, 2 );
 762                  $meta_compare_string = '%s AND %s';
 763              } elseif ( 'LIKE' == substr( $meta_compare, -4 ) ) {
 764                  $meta_value = '%' . like_escape( $meta_value ) . '%';
 765                  $meta_compare_string = '%s';
 766              } else {
 767                  $meta_compare_string = '%s';
 768              }
 769  
 770              if ( ! empty( $where[$k] ) )
 771                  $where[$k] .= ' AND ';
 772  
 773              $where[$k] = ' (' . $where[$k] . $wpdb->prepare( "CAST($alias.meta_value AS {$meta_type}) {$meta_compare} {$meta_compare_string})", $meta_value );
 774          }
 775  
 776          $where = array_filter( $where );
 777  
 778          if ( empty( $where ) )
 779              $where = '';
 780          else
 781              $where = ' AND (' . implode( "\n{$this->relation} ", $where ) . ' )';
 782  
 783          $join = implode( "\n", $join );
 784          if ( ! empty( $join ) )
 785              $join = ' ' . $join;
 786  
 787          return apply_filters_ref_array( 'get_meta_sql', array( compact( 'join', 'where' ), $this->queries, $type, $primary_table, $primary_id_column, $context ) );
 788      }
 789  }
 790  
 791  /**
 792   * Retrieve the name of the metadata table for the specified object type.
 793   *
 794   * @since 2.9.0
 795   * @uses $wpdb WordPress database object for queries.
 796   *
 797   * @param string $type Type of object to get metadata table for (e.g., comment, post, or user)
 798   * @return mixed Metadata table name, or false if no metadata table exists
 799   */
 800  function _get_meta_table($type) {
 801      global $wpdb;
 802  
 803      $table_name = $type . 'meta';
 804  
 805      if ( empty($wpdb->$table_name) )
 806          return false;
 807  
 808      return $wpdb->$table_name;
 809  }
 810  
 811  /**
 812   * Determine whether a meta key is protected
 813   *
 814   * @since 3.1.3
 815   *
 816   * @param string $meta_key Meta key
 817   * @return bool True if the key is protected, false otherwise.
 818   */
 819  function is_protected_meta( $meta_key, $meta_type = null ) {
 820      $protected = ( '_' == $meta_key[0] );
 821  
 822      return apply_filters( 'is_protected_meta', $protected, $meta_key, $meta_type );
 823  }
 824  
 825  /**
 826   * Sanitize meta value
 827   *
 828   * @since 3.1.3
 829   *
 830   * @param string $meta_key Meta key
 831   * @param mixed $meta_value Meta value to sanitize
 832   * @param string $meta_type Type of meta
 833   * @return mixed Sanitized $meta_value
 834   */
 835  function sanitize_meta( $meta_key, $meta_value, $meta_type ) {
 836      return apply_filters( "sanitize_{$meta_type}_meta_{$meta_key}", $meta_value, $meta_key, $meta_type );
 837  }
 838  
 839  /**
 840   * Register meta key
 841   *
 842   * @since 3.3.0
 843   *
 844   * @param string $meta_type Type of meta
 845   * @param string $meta_key Meta key
 846   * @param string|array $sanitize_callback A function or method to call when sanitizing the value of $meta_key.
 847   * @param string|array $auth_callback Optional. A function or method to call when performing edit_post_meta, add_post_meta, and delete_post_meta capability checks.
 848   * @param array $args Arguments
 849   */
 850  function register_meta( $meta_type, $meta_key, $sanitize_callback, $auth_callback = null ) {
 851      if ( is_callable( $sanitize_callback ) )
 852          add_filter( "sanitize_{$meta_type}_meta_{$meta_key}", $sanitize_callback, 10, 3 );
 853  
 854      if ( empty( $auth_callback ) ) {
 855          if ( is_protected_meta( $meta_key, $meta_type ) )
 856              $auth_callback = '__return_false';
 857          else
 858              $auth_callback = '__return_true';
 859      }
 860  
 861      if ( is_callable( $auth_callback ) )
 862          add_filter( "auth_{$meta_type}_meta_{$meta_key}", $auth_callback, 10, 6 );
 863  }


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