Elgg / Elgg

engine/classes/Elgg/Database/MetadataTable.php

Indentation +751 added lines, -751 removed lines

@@ -19,203 +19,203 @@ 
  */
 class MetadataTable {
 
-	use \Elgg\TimeUsing;
+    use \Elgg\TimeUsing;
 
-	/** @var array */
-	protected $independents = [];
+    /** @var array */
+    protected $independents = [];
 	
-	/** @var Cache */
-	protected $cache;
+    /** @var Cache */
+    protected $cache;
 	
-	/** @var Database */
-	protected $db;
+    /** @var Database */
+    protected $db;
 	
-	/** @var EntityTable */
-	protected $entityTable;
+    /** @var EntityTable */
+    protected $entityTable;
 		
-	/** @var Events */
-	protected $events;
-	
-	/** @var Session */
-	protected $session;
-	
-	/** @var string */
-	protected $table;
-	const MYSQL_TEXT_BYTE_LIMIT = 65535;
-	/**
-	 * Constructor
-	 *
-	 * @param Cache       $cache       A cache for this table
-	 * @param Database    $db          The Elgg database
-	 * @param EntityTable $entityTable The entities table
-	 * @param Events      $events      The events registry
-	 * @param Session     $session     The session
-	 */
-	public function __construct(
-			Cache $cache,
-			Database $db,
-			EntityTable $entityTable,
-			Events $events,
-			Session $session) {
-		$this->cache = $cache;
-		$this->db = $db;
-		$this->entityTable = $entityTable;
-		$this->events = $events;
-		$this->session = $session;
-		$this->table = $this->db->prefix . "metadata";
-	}
+    /** @var Events */
+    protected $events;
+	
+    /** @var Session */
+    protected $session;
+	
+    /** @var string */
+    protected $table;
+    const MYSQL_TEXT_BYTE_LIMIT = 65535;
+    /**
+     * Constructor
+     *
+     * @param Cache       $cache       A cache for this table
+     * @param Database    $db          The Elgg database
+     * @param EntityTable $entityTable The entities table
+     * @param Events      $events      The events registry
+     * @param Session     $session     The session
+     */
+    public function __construct(
+            Cache $cache,
+            Database $db,
+            EntityTable $entityTable,
+            Events $events,
+            Session $session) {
+        $this->cache = $cache;
+        $this->db = $db;
+        $this->entityTable = $entityTable;
+        $this->events = $events;
+        $this->session = $session;
+        $this->table = $this->db->prefix . "metadata";
+    }
 
-	/**
-	 * Get a specific metadata object by its id.
-	 * If you want multiple metadata objects, use
-	 * {@link elgg_get_metadata()}.
-	 *
-	 * @param int $id The id of the metadata object being retrieved.
-	 *
-	 * @return \ElggMetadata|false  false if not found
-	 */
-	function get($id) {
-		return _elgg_get_metastring_based_object_from_id($id, 'metadata');
-	}
-	
-	/**
-	 * Deletes metadata using its ID.
-	 *
-	 * @param int $id The metadata ID to delete.
-	 * @return bool
-	 */
-	function delete($id) {
-		$metadata = $this->get($id);
+    /**
+     * Get a specific metadata object by its id.
+     * If you want multiple metadata objects, use
+     * {@link elgg_get_metadata()}.
+     *
+     * @param int $id The id of the metadata object being retrieved.
+     *
+     * @return \ElggMetadata|false  false if not found
+     */
+    function get($id) {
+        return _elgg_get_metastring_based_object_from_id($id, 'metadata');
+    }
+	
+    /**
+     * Deletes metadata using its ID.
+     *
+     * @param int $id The metadata ID to delete.
+     * @return bool
+     */
+    function delete($id) {
+        $metadata = $this->get($id);
 
-		return $metadata ? $metadata->delete() : false;
-	}
-	
-	/**
-	 * Create a new metadata object, or update an existing one.
-	 *
-	 * Metadata can be an array by setting allow_multiple to true, but it is an
-	 * indexed array with no control over the indexing.
-	 *
-	 * @param int    $entity_guid    The entity to attach the metadata to
-	 * @param string $name           Name of the metadata
-	 * @param string $value          Value of the metadata
-	 * @param string $value_type     'text', 'integer', or '' for automatic detection
-	 * @param int    $owner_guid     GUID of entity that owns the metadata. Default is logged in user.
-	 * @param int    $access_id      Default is ACCESS_PRIVATE
-	 * @param bool   $allow_multiple Allow multiple values for one key. Default is false
-	 *
-	 * @return int|false id of metadata or false if failure
-	 */
-	function create($entity_guid, $name, $value, $value_type = '', $owner_guid = 0,
-			$access_id = ACCESS_PRIVATE, $allow_multiple = false) {
+        return $metadata ? $metadata->delete() : false;
+    }
+	
+    /**
+     * Create a new metadata object, or update an existing one.
+     *
+     * Metadata can be an array by setting allow_multiple to true, but it is an
+     * indexed array with no control over the indexing.
+     *
+     * @param int    $entity_guid    The entity to attach the metadata to
+     * @param string $name           Name of the metadata
+     * @param string $value          Value of the metadata
+     * @param string $value_type     'text', 'integer', or '' for automatic detection
+     * @param int    $owner_guid     GUID of entity that owns the metadata. Default is logged in user.
+     * @param int    $access_id      Default is ACCESS_PRIVATE
+     * @param bool   $allow_multiple Allow multiple values for one key. Default is false
+     *
+     * @return int|false id of metadata or false if failure
+     */
+    function create($entity_guid, $name, $value, $value_type = '', $owner_guid = 0,
+            $access_id = ACCESS_PRIVATE, $allow_multiple = false) {
 
-		$entity_guid = (int) $entity_guid;
-		$value_type = \ElggExtender::detectValueType($value, trim($value_type));
-		$owner_guid = (int) $owner_guid;
-		$allow_multiple = (boolean) $allow_multiple;
+        $entity_guid = (int) $entity_guid;
+        $value_type = \ElggExtender::detectValueType($value, trim($value_type));
+        $owner_guid = (int) $owner_guid;
+        $allow_multiple = (boolean) $allow_multiple;
 
-		if (!isset($value)) {
-			return false;
-		}
-	
-		if ($owner_guid == 0) {
-			$owner_guid = $this->session->getLoggedInUserGuid();
-		}
-	
-		$access_id = (int) $access_id;
-		if (strlen($value) > self::MYSQL_TEXT_BYTE_LIMIT) {
-			elgg_log("Metadata '$name' is above the MySQL TEXT size limit and may be truncated.", 'WARNING');
-		}
-		$query = "SELECT * FROM {$this->table}
+        if (!isset($value)) {
+            return false;
+        }
+	
+        if ($owner_guid == 0) {
+            $owner_guid = $this->session->getLoggedInUserGuid();
+        }
+	
+        $access_id = (int) $access_id;
+        if (strlen($value) > self::MYSQL_TEXT_BYTE_LIMIT) {
+            elgg_log("Metadata '$name' is above the MySQL TEXT size limit and may be truncated.", 'WARNING');
+        }
+        $query = "SELECT * FROM {$this->table}
 			WHERE entity_guid = :entity_guid and name = :name LIMIT 1";
 
-		$existing = $this->db->getDataRow($query, null, [
-			':entity_guid' => $entity_guid,
-			':name' => $name,
-		]);
-		if ($existing && !$allow_multiple) {
-			$id = (int) $existing->id;
-			$result = $this->update($id, $name, $value, $value_type, $owner_guid, $access_id);
-	
-			if (!$result) {
-				return false;
-			}
-		} else {
-			// Support boolean types
-			if (is_bool($value)) {
-				$value = (int) $value;
-			}
+        $existing = $this->db->getDataRow($query, null, [
+            ':entity_guid' => $entity_guid,
+            ':name' => $name,
+        ]);
+        if ($existing && !$allow_multiple) {
+            $id = (int) $existing->id;
+            $result = $this->update($id, $name, $value, $value_type, $owner_guid, $access_id);
+	
+            if (!$result) {
+                return false;
+            }
+        } else {
+            // Support boolean types
+            if (is_bool($value)) {
+                $value = (int) $value;
+            }
 		
-			// If ok then add it
-			$query = "INSERT INTO {$this->table}
+            // If ok then add it
+            $query = "INSERT INTO {$this->table}
 				(entity_guid, name, value, value_type, owner_guid, time_created, access_id)
 				VALUES (:entity_guid, :name, :value, :value_type, :owner_guid, :time_created, :access_id)";
 			
-			$id = $this->db->insertData($query, [
-				':entity_guid' => $entity_guid,
-				':name' => $name,
-				':value' => $value,
-				':value_type' => $value_type,
-				':owner_guid' => (int) $owner_guid,
-				':time_created' => $this->getCurrentTime()->getTimestamp(),
-				':access_id' => $access_id,
-			]);
+            $id = $this->db->insertData($query, [
+                ':entity_guid' => $entity_guid,
+                ':name' => $name,
+                ':value' => $value,
+                ':value_type' => $value_type,
+                ':owner_guid' => (int) $owner_guid,
+                ':time_created' => $this->getCurrentTime()->getTimestamp(),
+                ':access_id' => $access_id,
+            ]);
 			
-			if ($id !== false) {
-				$obj = $this->get($id);
-				if ($this->events->trigger('create', 'metadata', $obj)) {
-					$this->cache->clear($entity_guid);
-	
-					return $id;
-				} else {
-					$this->delete($id);
-				}
-			}
-		}
-	
-		return $id;
-	}
-	
-	/**
-	 * Update a specific piece of metadata.
-	 *
-	 * @param int    $id         ID of the metadata to update
-	 * @param string $name       Metadata name
-	 * @param string $value      Metadata value
-	 * @param string $value_type Value type
-	 * @param int    $owner_guid Owner guid
-	 * @param int    $access_id  Access ID
-	 *
-	 * @return bool
-	 */
-	function update($id, $name, $value, $value_type, $owner_guid, $access_id) {
-		$id = (int) $id;
-	
-		if (!$md = $this->get($id)) {
-			return false;
-		}
-		if (!$md->canEdit()) {
-			return false;
-		}
-	
-		$value_type = \ElggExtender::detectValueType($value, trim($value_type));
-	
-		$owner_guid = (int) $owner_guid;
-		if ($owner_guid == 0) {
-			$owner_guid = $this->session->getLoggedInUserGuid();
-		}
-	
-		$access_id = (int) $access_id;
-	
-		// Support boolean types (as integers)
-		if (is_bool($value)) {
-			$value = (int) $value;
-		}
-		if (strlen($value) > self::MYSQL_TEXT_BYTE_LIMIT) {
-			elgg_log("Metadata '$name' is above the MySQL TEXT size limit and may be truncated.", 'WARNING');
-		}
-		// If ok then add it
-		$query = "UPDATE {$this->table}
+            if ($id !== false) {
+                $obj = $this->get($id);
+                if ($this->events->trigger('create', 'metadata', $obj)) {
+                    $this->cache->clear($entity_guid);
+	
+                    return $id;
+                } else {
+                    $this->delete($id);
+                }
+            }
+        }
+	
+        return $id;
+    }
+	
+    /**
+     * Update a specific piece of metadata.
+     *
+     * @param int    $id         ID of the metadata to update
+     * @param string $name       Metadata name
+     * @param string $value      Metadata value
+     * @param string $value_type Value type
+     * @param int    $owner_guid Owner guid
+     * @param int    $access_id  Access ID
+     *
+     * @return bool
+     */
+    function update($id, $name, $value, $value_type, $owner_guid, $access_id) {
+        $id = (int) $id;
+	
+        if (!$md = $this->get($id)) {
+            return false;
+        }
+        if (!$md->canEdit()) {
+            return false;
+        }
+	
+        $value_type = \ElggExtender::detectValueType($value, trim($value_type));
+	
+        $owner_guid = (int) $owner_guid;
+        if ($owner_guid == 0) {
+            $owner_guid = $this->session->getLoggedInUserGuid();
+        }
+	
+        $access_id = (int) $access_id;
+	
+        // Support boolean types (as integers)
+        if (is_bool($value)) {
+            $value = (int) $value;
+        }
+        if (strlen($value) > self::MYSQL_TEXT_BYTE_LIMIT) {
+            elgg_log("Metadata '$name' is above the MySQL TEXT size limit and may be truncated.", 'WARNING');
+        }
+        // If ok then add it
+        $query = "UPDATE {$this->table}
 			SET name = :name,
 			    value = :value,
 				value_type = :value_type,
@@ -223,588 +223,588 @@ 
 			    owner_guid = :owner_guid
 			WHERE id = :id";
 		
-		$result = $this->db->updateData($query, false, [
-			':name' => $name,
-			':value' => $value,
-			':value_type' => $value_type,
-			':access_id' => $access_id,
-			':owner_guid' => $owner_guid,
-			':id' => $id,
-		]);
+        $result = $this->db->updateData($query, false, [
+            ':name' => $name,
+            ':value' => $value,
+            ':value_type' => $value_type,
+            ':access_id' => $access_id,
+            ':owner_guid' => $owner_guid,
+            ':id' => $id,
+        ]);
 		
-		if ($result !== false) {
-			$this->cache->clear($md->entity_guid);
-	
-			// @todo this event tells you the metadata has been updated, but does not
-			// let you do anything about it. What is needed is a plugin hook before
-			// the update that passes old and new values.
-			$obj = $this->get($id);
-			$this->events->trigger('update', 'metadata', $obj);
-		}
-	
-		return $result;
-	}
-	
-	/**
-	 * This function creates metadata from an associative array of "key => value" pairs.
-	 *
-	 * To achieve an array for a single key, pass in the same key multiple times with
-	 * allow_multiple set to true. This creates an indexed array. It does not support
-	 * associative arrays and there is no guarantee on the ordering in the array.
-	 *
-	 * @param int    $entity_guid     The entity to attach the metadata to
-	 * @param array  $name_and_values Associative array - a value can be a string, number, bool
-	 * @param string $value_type      'text', 'integer', or '' for automatic detection
-	 * @param int    $owner_guid      GUID of entity that owns the metadata
-	 * @param int    $access_id       Default is ACCESS_PRIVATE
-	 * @param bool   $allow_multiple  Allow multiple values for one key. Default is false
-	 *
-	 * @return bool
-	 */
-	function createFromArray($entity_guid, array $name_and_values, $value_type, $owner_guid,
-			$access_id = ACCESS_PRIVATE, $allow_multiple = false) {
-	
-		foreach ($name_and_values as $k => $v) {
-			$result = $this->create($entity_guid, $k, $v, $value_type, $owner_guid,
-				$access_id, $allow_multiple);
-			if (!$result) {
-				return false;
-			}
-		}
-		return true;
-	}
-	
-	/**
-	 * Returns metadata.  Accepts all elgg_get_entities() options for entity
-	 * restraints.
-	 *
-	 * @see elgg_get_entities
-	 *
-	 * @warning 1.7's find_metadata() didn't support limits and returned all metadata.
-	 *          This function defaults to a limit of 25. There is probably not a reason
-	 *          for you to return all metadata unless you're exporting an entity,
-	 *          have other restraints in place, or are doing something horribly
-	 *          wrong in your code.
-	 *
-	 * @param array $options Array in format:
-	 *
-	 * metadata_names               => null|ARR metadata names
-	 * metadata_values              => null|ARR metadata values
-	 * metadata_ids                 => null|ARR metadata ids
-	 * metadata_case_sensitive      => BOOL Overall Case sensitive
-	 * metadata_owner_guids         => null|ARR guids for metadata owners
-	 * metadata_created_time_lower  => INT Lower limit for created time.
-	 * metadata_created_time_upper  => INT Upper limit for created time.
-	 * metadata_calculation         => STR Perform the MySQL function on the metadata values returned.
-	 *                                   The "metadata_calculation" option causes this function to
-	 *                                   return the result of performing a mathematical calculation on
-	 *                                   all metadata that match the query instead of returning
-	 *                                   \ElggMetadata objects.
-	 *
-	 * @return \ElggMetadata[]|mixed
-	 */
-	function getAll(array $options = []) {
-	
-		// @todo remove support for count shortcut - see #4393
-		// support shortcut of 'count' => true for 'metadata_calculation' => 'count'
-		if (isset($options['count']) && $options['count']) {
-			$options['metadata_calculation'] = 'count';
-			unset($options['count']);
-		}
-	
-		$options['metastring_type'] = 'metadata';
-		return _elgg_get_metastring_based_objects($options);
-	}
-	
-	/**
-	 * Deletes metadata based on $options.
-	 *
-	 * @warning Unlike elgg_get_metadata() this will not accept an empty options array!
-	 *          This requires at least one constraint: metadata_owner_guid(s),
-	 *          metadata_name(s), metadata_value(s), or guid(s) must be set.
-	 *
-	 * @param array $options An options array. {@link elgg_get_metadata()}
-	 * @return bool|null true on success, false on failure, null if no metadata to delete.
-	 */
-	function deleteAll(array $options) {
-		if (!_elgg_is_valid_options_for_batch_operation($options, 'metadata')) {
-			return false;
-		}
-		$options['metastring_type'] = 'metadata';
-		$result = _elgg_batch_metastring_based_objects($options, 'elgg_batch_delete_callback', false);
-	
-		// This moved last in case an object's constructor sets metadata. Currently the batch
-		// delete process has to create the entity to delete its metadata. See #5214
-		$this->cache->invalidateByOptions($options);
-	
-		return $result;
-	}
-	
-	/**
-	 * Disables metadata based on $options.
-	 *
-	 * @warning Unlike elgg_get_metadata() this will not accept an empty options array!
-	 *
-	 * @param array $options An options array. {@link elgg_get_metadata()}
-	 * @return bool|null true on success, false on failure, null if no metadata disabled.
-	 */
-	function disableAll(array $options) {
-		if (!_elgg_is_valid_options_for_batch_operation($options, 'metadata')) {
-			return false;
-		}
-	
-		$this->cache->invalidateByOptions($options);
-	
-		// if we can see hidden (disabled) we need to use the offset
-		// otherwise we risk an infinite loop if there are more than 50
-		$inc_offset = access_get_show_hidden_status();
-	
-		$options['metastring_type'] = 'metadata';
-		return _elgg_batch_metastring_based_objects($options, 'elgg_batch_disable_callback', $inc_offset);
-	}
-	
-	/**
-	 * Enables metadata based on $options.
-	 *
-	 * @warning Unlike elgg_get_metadata() this will not accept an empty options array!
-	 *
-	 * @warning In order to enable metadata, you must first use
-	 * {@link access_show_hidden_entities()}.
-	 *
-	 * @param array $options An options array. {@link elgg_get_metadata()}
-	 * @return bool|null true on success, false on failure, null if no metadata enabled.
-	 */
-	function enableAll(array $options) {
-		if (!$options || !is_array($options)) {
-			return false;
-		}
-	
-		$this->cache->invalidateByOptions($options);
-	
-		$options['metastring_type'] = 'metadata';
-		return _elgg_batch_metastring_based_objects($options, 'elgg_batch_enable_callback');
-	}
-	
-	/**
-	 * Returns entities based upon metadata.  Also accepts all
-	 * options available to elgg_get_entities().  Supports
-	 * the singular option shortcut.
-	 *
-	 * @note Using metadata_names and metadata_values results in a
-	 * "names IN (...) AND values IN (...)" clause.  This is subtly
-	 * differently than default multiple metadata_name_value_pairs, which use
-	 * "(name = value) AND (name = value)" clauses.
-	 *
-	 * When in doubt, use name_value_pairs.
-	 *
-	 * To ask for entities that do not have a metadata value, use a custom
-	 * where clause like this:
-	 *
-	 * 	$options['wheres'][] = "NOT EXISTS (
-	 *			SELECT 1 FROM {$dbprefix}metadata md
-	 *			WHERE md.entity_guid = e.guid
-	 *				AND md.name = $name
-	 *				AND md.value = $value)";
-	 *
-	 * Note the metadata name and value has been denormalized in the above example.
-	 *
-	 * @see elgg_get_entities
-	 *
-	 * @param array $options Array in format:
-	 *
-	 * 	metadata_names => null|ARR metadata names
-	 *
-	 * 	metadata_values => null|ARR metadata values
-	 *
-	 * 	metadata_name_value_pairs => null|ARR (
-	 *                                         name => 'name',
-	 *                                         value => 'value',
-	 *                                         'operand' => '=',
-	 *                                         'case_sensitive' => true
-	 *                                        )
-	 *                               Currently if multiple values are sent via
-	 *                               an array (value => array('value1', 'value2')
-	 *                               the pair's operand will be forced to "IN".
-	 *                               If passing "IN" as the operand and a string as the value,
-	 *                               the value must be a properly quoted and escaped string.
-	 *
-	 * 	metadata_name_value_pairs_operator => null|STR The operator to use for combining
-	 *                                        (name = value) OPERATOR (name = value); default AND
-	 *
-	 * 	metadata_case_sensitive => BOOL Overall Case sensitive
-	 *
-	 *  order_by_metadata => null|ARR array(
-	 *                                      'name' => 'metadata_text1',
-	 *                                      'direction' => ASC|DESC,
-	 *                                      'as' => text|integer
-	 *                                     )
-	 *                                Also supports array('name' => 'metadata_text1')
-	 *
-	 *  metadata_owner_guids => null|ARR guids for metadata owners
-	 *
-	 * @return \ElggEntity[]|mixed If count, int. If not count, array. false on errors.
-	 */
-	function getEntities(array $options = []) {
-		$defaults = [
-			'metadata_names'                     => ELGG_ENTITIES_ANY_VALUE,
-			'metadata_values'                    => ELGG_ENTITIES_ANY_VALUE,
-			'metadata_name_value_pairs'          => ELGG_ENTITIES_ANY_VALUE,
-	
-			'metadata_name_value_pairs_operator' => 'AND',
-			'metadata_case_sensitive'            => true,
-			'order_by_metadata'                  => [],
-	
-			'metadata_owner_guids'               => ELGG_ENTITIES_ANY_VALUE,
-		];
-	
-		$options = array_merge($defaults, $options);
-	
-		$singulars = ['metadata_name', 'metadata_value',
-			'metadata_name_value_pair', 'metadata_owner_guid'];
-	
-		$options = _elgg_normalize_plural_options_array($options, $singulars);
-	
-		if (!$options = _elgg_entities_get_metastrings_options('metadata', $options)) {
-			return false;
-		}
-	
-		return $this->entityTable->getEntities($options);
-	}
-	
-	/**
-	 * Returns metadata name and value SQL where for entities.
-	 * NB: $names and $values are not paired. Use $pairs for this.
-	 * Pairs default to '=' operand.
-	 *
-	 * This function is reused for annotations because the tables are
-	 * exactly the same.
-	 *
-	 * @param string     $e_table           Entities table name
-	 * @param string     $n_table           Normalized metastrings table name (Where entities,
-	 *                                    values, and names are joined. annotations / metadata)
-	 * @param array|null $names             Array of names
-	 * @param array|null $values            Array of values
-	 * @param array|null $pairs             Array of names / values / operands
-	 * @param string     $pair_operator     ("AND" or "OR") Operator to use to join the where clauses for pairs
-	 * @param bool       $case_sensitive    Case sensitive metadata names?
-	 * @param array|null $order_by_metadata Array of names / direction
-	 * @param array|null $owner_guids       Array of owner GUIDs
-	 *
-	 * @return false|array False on fail, array('joins', 'wheres')
-	 * @access private
-	 */
-	function getEntityMetadataWhereSql($e_table, $n_table, $names = null, $values = null,
-			$pairs = null, $pair_operator = 'AND', $case_sensitive = true, $order_by_metadata = null,
-			$owner_guids = null) {
-		// short circuit if nothing requested
-		// 0 is a valid (if not ill-conceived) metadata name.
-		// 0 is also a valid metadata value for false, null, or 0
-		// 0 is also a valid(ish) owner_guid
-		if ((!$names && $names !== 0)
-			&& (!$values && $values !== 0)
-			&& (!$pairs && $pairs !== 0)
-			&& (!$owner_guids && $owner_guids !== 0)
-			&& !$order_by_metadata) {
-			return '';
-		}
-	
-		// join counter for incremental joins.
-		$i = 1;
-	
-		// binary forces byte-to-byte comparision of strings, making
-		// it case- and diacritical-mark- sensitive.
-		// only supported on values.
-		$binary = ($case_sensitive) ? ' BINARY ' : '';
-	
-		$access = _elgg_get_access_where_sql([
-			'table_alias' => 'n_table',
-			'guid_column' => 'entity_guid',
-		]);
-	
-		$return =  [
-			'joins' =>  [],
-			'wheres' => [],
-			'orders' => []
-		];
-	
-		$return['joins'][] = "JOIN {$this->db->prefix}{$n_table} n_table on
+        if ($result !== false) {
+            $this->cache->clear($md->entity_guid);
+	
+            // @todo this event tells you the metadata has been updated, but does not
+            // let you do anything about it. What is needed is a plugin hook before
+            // the update that passes old and new values.
+            $obj = $this->get($id);
+            $this->events->trigger('update', 'metadata', $obj);
+        }
+	
+        return $result;
+    }
+	
+    /**
+     * This function creates metadata from an associative array of "key => value" pairs.
+     *
+     * To achieve an array for a single key, pass in the same key multiple times with
+     * allow_multiple set to true. This creates an indexed array. It does not support
+     * associative arrays and there is no guarantee on the ordering in the array.
+     *
+     * @param int    $entity_guid     The entity to attach the metadata to
+     * @param array  $name_and_values Associative array - a value can be a string, number, bool
+     * @param string $value_type      'text', 'integer', or '' for automatic detection
+     * @param int    $owner_guid      GUID of entity that owns the metadata
+     * @param int    $access_id       Default is ACCESS_PRIVATE
+     * @param bool   $allow_multiple  Allow multiple values for one key. Default is false
+     *
+     * @return bool
+     */
+    function createFromArray($entity_guid, array $name_and_values, $value_type, $owner_guid,
+            $access_id = ACCESS_PRIVATE, $allow_multiple = false) {
+	
+        foreach ($name_and_values as $k => $v) {
+            $result = $this->create($entity_guid, $k, $v, $value_type, $owner_guid,
+                $access_id, $allow_multiple);
+            if (!$result) {
+                return false;
+            }
+        }
+        return true;
+    }
+	
+    /**
+     * Returns metadata.  Accepts all elgg_get_entities() options for entity
+     * restraints.
+     *
+     * @see elgg_get_entities
+     *
+     * @warning 1.7's find_metadata() didn't support limits and returned all metadata.
+     *          This function defaults to a limit of 25. There is probably not a reason
+     *          for you to return all metadata unless you're exporting an entity,
+     *          have other restraints in place, or are doing something horribly
+     *          wrong in your code.
+     *
+     * @param array $options Array in format:
+     *
+     * metadata_names               => null|ARR metadata names
+     * metadata_values              => null|ARR metadata values
+     * metadata_ids                 => null|ARR metadata ids
+     * metadata_case_sensitive      => BOOL Overall Case sensitive
+     * metadata_owner_guids         => null|ARR guids for metadata owners
+     * metadata_created_time_lower  => INT Lower limit for created time.
+     * metadata_created_time_upper  => INT Upper limit for created time.
+     * metadata_calculation         => STR Perform the MySQL function on the metadata values returned.
+     *                                   The "metadata_calculation" option causes this function to
+     *                                   return the result of performing a mathematical calculation on
+     *                                   all metadata that match the query instead of returning
+     *                                   \ElggMetadata objects.
+     *
+     * @return \ElggMetadata[]|mixed
+     */
+    function getAll(array $options = []) {
+	
+        // @todo remove support for count shortcut - see #4393
+        // support shortcut of 'count' => true for 'metadata_calculation' => 'count'
+        if (isset($options['count']) && $options['count']) {
+            $options['metadata_calculation'] = 'count';
+            unset($options['count']);
+        }
+	
+        $options['metastring_type'] = 'metadata';
+        return _elgg_get_metastring_based_objects($options);
+    }
+	
+    /**
+     * Deletes metadata based on $options.
+     *
+     * @warning Unlike elgg_get_metadata() this will not accept an empty options array!
+     *          This requires at least one constraint: metadata_owner_guid(s),
+     *          metadata_name(s), metadata_value(s), or guid(s) must be set.
+     *
+     * @param array $options An options array. {@link elgg_get_metadata()}
+     * @return bool|null true on success, false on failure, null if no metadata to delete.
+     */
+    function deleteAll(array $options) {
+        if (!_elgg_is_valid_options_for_batch_operation($options, 'metadata')) {
+            return false;
+        }
+        $options['metastring_type'] = 'metadata';
+        $result = _elgg_batch_metastring_based_objects($options, 'elgg_batch_delete_callback', false);
+	
+        // This moved last in case an object's constructor sets metadata. Currently the batch
+        // delete process has to create the entity to delete its metadata. See #5214
+        $this->cache->invalidateByOptions($options);
+	
+        return $result;
+    }
+	
+    /**
+     * Disables metadata based on $options.
+     *
+     * @warning Unlike elgg_get_metadata() this will not accept an empty options array!
+     *
+     * @param array $options An options array. {@link elgg_get_metadata()}
+     * @return bool|null true on success, false on failure, null if no metadata disabled.
+     */
+    function disableAll(array $options) {
+        if (!_elgg_is_valid_options_for_batch_operation($options, 'metadata')) {
+            return false;
+        }
+	
+        $this->cache->invalidateByOptions($options);
+	
+        // if we can see hidden (disabled) we need to use the offset
+        // otherwise we risk an infinite loop if there are more than 50
+        $inc_offset = access_get_show_hidden_status();
+	
+        $options['metastring_type'] = 'metadata';
+        return _elgg_batch_metastring_based_objects($options, 'elgg_batch_disable_callback', $inc_offset);
+    }
+	
+    /**
+     * Enables metadata based on $options.
+     *
+     * @warning Unlike elgg_get_metadata() this will not accept an empty options array!
+     *
+     * @warning In order to enable metadata, you must first use
+     * {@link access_show_hidden_entities()}.
+     *
+     * @param array $options An options array. {@link elgg_get_metadata()}
+     * @return bool|null true on success, false on failure, null if no metadata enabled.
+     */
+    function enableAll(array $options) {
+        if (!$options || !is_array($options)) {
+            return false;
+        }
+	
+        $this->cache->invalidateByOptions($options);
+	
+        $options['metastring_type'] = 'metadata';
+        return _elgg_batch_metastring_based_objects($options, 'elgg_batch_enable_callback');
+    }
+	
+    /**
+     * Returns entities based upon metadata.  Also accepts all
+     * options available to elgg_get_entities().  Supports
+     * the singular option shortcut.
+     *
+     * @note Using metadata_names and metadata_values results in a
+     * "names IN (...) AND values IN (...)" clause.  This is subtly
+     * differently than default multiple metadata_name_value_pairs, which use
+     * "(name = value) AND (name = value)" clauses.
+     *
+     * When in doubt, use name_value_pairs.
+     *
+     * To ask for entities that do not have a metadata value, use a custom
+     * where clause like this:
+     *
+     * 	$options['wheres'][] = "NOT EXISTS (
+     *			SELECT 1 FROM {$dbprefix}metadata md
+     *			WHERE md.entity_guid = e.guid
+     *				AND md.name = $name
+     *				AND md.value = $value)";
+     *
+     * Note the metadata name and value has been denormalized in the above example.
+     *
+     * @see elgg_get_entities
+     *
+     * @param array $options Array in format:
+     *
+     * 	metadata_names => null|ARR metadata names
+     *
+     * 	metadata_values => null|ARR metadata values
+     *
+     * 	metadata_name_value_pairs => null|ARR (
+     *                                         name => 'name',
+     *                                         value => 'value',
+     *                                         'operand' => '=',
+     *                                         'case_sensitive' => true
+     *                                        )
+     *                               Currently if multiple values are sent via
+     *                               an array (value => array('value1', 'value2')
+     *                               the pair's operand will be forced to "IN".
+     *                               If passing "IN" as the operand and a string as the value,
+     *                               the value must be a properly quoted and escaped string.
+     *
+     * 	metadata_name_value_pairs_operator => null|STR The operator to use for combining
+     *                                        (name = value) OPERATOR (name = value); default AND
+     *
+     * 	metadata_case_sensitive => BOOL Overall Case sensitive
+     *
+     *  order_by_metadata => null|ARR array(
+     *                                      'name' => 'metadata_text1',
+     *                                      'direction' => ASC|DESC,
+     *                                      'as' => text|integer
+     *                                     )
+     *                                Also supports array('name' => 'metadata_text1')
+     *
+     *  metadata_owner_guids => null|ARR guids for metadata owners
+     *
+     * @return \ElggEntity[]|mixed If count, int. If not count, array. false on errors.
+     */
+    function getEntities(array $options = []) {
+        $defaults = [
+            'metadata_names'                     => ELGG_ENTITIES_ANY_VALUE,
+            'metadata_values'                    => ELGG_ENTITIES_ANY_VALUE,
+            'metadata_name_value_pairs'          => ELGG_ENTITIES_ANY_VALUE,
+	
+            'metadata_name_value_pairs_operator' => 'AND',
+            'metadata_case_sensitive'            => true,
+            'order_by_metadata'                  => [],
+	
+            'metadata_owner_guids'               => ELGG_ENTITIES_ANY_VALUE,
+        ];
+	
+        $options = array_merge($defaults, $options);
+	
+        $singulars = ['metadata_name', 'metadata_value',
+            'metadata_name_value_pair', 'metadata_owner_guid'];
+	
+        $options = _elgg_normalize_plural_options_array($options, $singulars);
+	
+        if (!$options = _elgg_entities_get_metastrings_options('metadata', $options)) {
+            return false;
+        }
+	
+        return $this->entityTable->getEntities($options);
+    }
+	
+    /**
+     * Returns metadata name and value SQL where for entities.
+     * NB: $names and $values are not paired. Use $pairs for this.
+     * Pairs default to '=' operand.
+     *
+     * This function is reused for annotations because the tables are
+     * exactly the same.
+     *
+     * @param string     $e_table           Entities table name
+     * @param string     $n_table           Normalized metastrings table name (Where entities,
+     *                                    values, and names are joined. annotations / metadata)
+     * @param array|null $names             Array of names
+     * @param array|null $values            Array of values
+     * @param array|null $pairs             Array of names / values / operands
+     * @param string     $pair_operator     ("AND" or "OR") Operator to use to join the where clauses for pairs
+     * @param bool       $case_sensitive    Case sensitive metadata names?
+     * @param array|null $order_by_metadata Array of names / direction
+     * @param array|null $owner_guids       Array of owner GUIDs
+     *
+     * @return false|array False on fail, array('joins', 'wheres')
+     * @access private
+     */
+    function getEntityMetadataWhereSql($e_table, $n_table, $names = null, $values = null,
+            $pairs = null, $pair_operator = 'AND', $case_sensitive = true, $order_by_metadata = null,
+            $owner_guids = null) {
+        // short circuit if nothing requested
+        // 0 is a valid (if not ill-conceived) metadata name.
+        // 0 is also a valid metadata value for false, null, or 0
+        // 0 is also a valid(ish) owner_guid
+        if ((!$names && $names !== 0)
+            && (!$values && $values !== 0)
+            && (!$pairs && $pairs !== 0)
+            && (!$owner_guids && $owner_guids !== 0)
+            && !$order_by_metadata) {
+            return '';
+        }
+	
+        // join counter for incremental joins.
+        $i = 1;
+	
+        // binary forces byte-to-byte comparision of strings, making
+        // it case- and diacritical-mark- sensitive.
+        // only supported on values.
+        $binary = ($case_sensitive) ? ' BINARY ' : '';
+	
+        $access = _elgg_get_access_where_sql([
+            'table_alias' => 'n_table',
+            'guid_column' => 'entity_guid',
+        ]);
+	
+        $return =  [
+            'joins' =>  [],
+            'wheres' => [],
+            'orders' => []
+        ];
+	
+        $return['joins'][] = "JOIN {$this->db->prefix}{$n_table} n_table on
 			{$e_table}.guid = n_table.entity_guid";
 	
-		$wheres = [];
-	
-		// get names wheres and joins
-		$names_where = '';
-		if ($names !== null) {
-			if (!is_array($names)) {
-				$names = [$names];
-			}
-	
-			$sanitised_names = [];
-			foreach ($names as $name) {
-				// normalise to 0.
-				if (!$name) {
-					$name = '0';
-				}
-				$sanitised_names[] = '\'' . $this->db->sanitizeString($name) . '\'';
-			}
-	
-			if ($names_str = implode(',', $sanitised_names)) {
-				$names_where = "(n_table.name IN ($names_str))";
-			}
-		}
-	
-		// get values wheres and joins
-		$values_where = '';
-		if ($values !== null) {
-			if (!is_array($values)) {
-				$values = [$values];
-			}
-	
-			$sanitised_values = [];
-			foreach ($values as $value) {
-				// normalize to 0
-				if (!$value) {
-					$value = 0;
-				}
-				$sanitised_values[] = '\'' . $this->db->sanitizeString($value) . '\'';
-			}
-	
-			if ($values_str = implode(',', $sanitised_values)) {
-				$values_where = "({$binary}n_table.value IN ($values_str))";
-			}
-		}
-	
-		if ($names_where && $values_where) {
-			$wheres[] = "($names_where AND $values_where AND $access)";
-		} elseif ($names_where) {
-			$wheres[] = "($names_where AND $access)";
-		} elseif ($values_where) {
-			$wheres[] = "($values_where AND $access)";
-		}
-	
-		// add pairs
-		// pairs must be in arrays.
-		if (is_array($pairs)) {
-			// check if this is an array of pairs or just a single pair.
-			if (isset($pairs['name']) || isset($pairs['value'])) {
-				$pairs = [$pairs];
-			}
-	
-			$pair_wheres = [];
-	
-			// @todo when the pairs are > 3 should probably split the query up to
-			// denormalize the strings table.
-	
-			foreach ($pairs as $index => $pair) {
-				// @todo move this elsewhere?
-				// support shortcut 'n' => 'v' method.
-				if (!is_array($pair)) {
-					$pair = [
-						'name' => $index,
-						'value' => $pair
-					];
-				}
-	
-				// must have at least a name and value
-				if (!isset($pair['name']) || !isset($pair['value'])) {
-					// @todo should probably return false.
-					continue;
-				}
-	
-				// case sensitivity can be specified per pair.
-				// default to higher level setting.
-				if (isset($pair['case_sensitive'])) {
-					$pair_binary = ($pair['case_sensitive']) ? ' BINARY ' : '';
-				} else {
-					$pair_binary = $binary;
-				}
-	
-				if (isset($pair['operand'])) {
-					$operand = $this->db->sanitizeString($pair['operand']);
-				} else {
-					$operand = ' = ';
-				}
-	
-				// for comparing
-				$trimmed_operand = trim(strtolower($operand));
-	
-				$access = _elgg_get_access_where_sql([
-					'table_alias' => "n_table{$i}",
-					'guid_column' => 'entity_guid',
-				]);
+        $wheres = [];
+	
+        // get names wheres and joins
+        $names_where = '';
+        if ($names !== null) {
+            if (!is_array($names)) {
+                $names = [$names];
+            }
+	
+            $sanitised_names = [];
+            foreach ($names as $name) {
+                // normalise to 0.
+                if (!$name) {
+                    $name = '0';
+                }
+                $sanitised_names[] = '\'' . $this->db->sanitizeString($name) . '\'';
+            }
+	
+            if ($names_str = implode(',', $sanitised_names)) {
+                $names_where = "(n_table.name IN ($names_str))";
+            }
+        }
+	
+        // get values wheres and joins
+        $values_where = '';
+        if ($values !== null) {
+            if (!is_array($values)) {
+                $values = [$values];
+            }
+	
+            $sanitised_values = [];
+            foreach ($values as $value) {
+                // normalize to 0
+                if (!$value) {
+                    $value = 0;
+                }
+                $sanitised_values[] = '\'' . $this->db->sanitizeString($value) . '\'';
+            }
+	
+            if ($values_str = implode(',', $sanitised_values)) {
+                $values_where = "({$binary}n_table.value IN ($values_str))";
+            }
+        }
+	
+        if ($names_where && $values_where) {
+            $wheres[] = "($names_where AND $values_where AND $access)";
+        } elseif ($names_where) {
+            $wheres[] = "($names_where AND $access)";
+        } elseif ($values_where) {
+            $wheres[] = "($values_where AND $access)";
+        }
+	
+        // add pairs
+        // pairs must be in arrays.
+        if (is_array($pairs)) {
+            // check if this is an array of pairs or just a single pair.
+            if (isset($pairs['name']) || isset($pairs['value'])) {
+                $pairs = [$pairs];
+            }
+	
+            $pair_wheres = [];
+	
+            // @todo when the pairs are > 3 should probably split the query up to
+            // denormalize the strings table.
+	
+            foreach ($pairs as $index => $pair) {
+                // @todo move this elsewhere?
+                // support shortcut 'n' => 'v' method.
+                if (!is_array($pair)) {
+                    $pair = [
+                        'name' => $index,
+                        'value' => $pair
+                    ];
+                }
+	
+                // must have at least a name and value
+                if (!isset($pair['name']) || !isset($pair['value'])) {
+                    // @todo should probably return false.
+                    continue;
+                }
+	
+                // case sensitivity can be specified per pair.
+                // default to higher level setting.
+                if (isset($pair['case_sensitive'])) {
+                    $pair_binary = ($pair['case_sensitive']) ? ' BINARY ' : '';
+                } else {
+                    $pair_binary = $binary;
+                }
+	
+                if (isset($pair['operand'])) {
+                    $operand = $this->db->sanitizeString($pair['operand']);
+                } else {
+                    $operand = ' = ';
+                }
+	
+                // for comparing
+                $trimmed_operand = trim(strtolower($operand));
+	
+                $access = _elgg_get_access_where_sql([
+                    'table_alias' => "n_table{$i}",
+                    'guid_column' => 'entity_guid',
+                ]);
 
-				// certain operands can't work well with strings that can be interpreted as numbers
-				// for direct comparisons like IN, =, != we treat them as strings
-				// gt/lt comparisons need to stay unencapsulated because strings '5' > '15'
-				// see https://github.com/Elgg/Elgg/issues/7009
-				$num_safe_operands = ['>', '<', '>=', '<='];
-				$num_test_operand = trim(strtoupper($operand));
-	
-				if (is_numeric($pair['value']) && in_array($num_test_operand, $num_safe_operands)) {
-					$value = $this->db->sanitizeString($pair['value']);
-				} else if (is_bool($pair['value'])) {
-					$value = (int) $pair['value'];
-				} else if (is_array($pair['value'])) {
-					$values_array = [];
-	
-					foreach ($pair['value'] as $pair_value) {
-						if (is_numeric($pair_value) && !in_array($num_test_operand, $num_safe_operands)) {
-							$values_array[] = $this->db->sanitizeString($pair_value);
-						} else {
-							$values_array[] = "'" . $this->db->sanitizeString($pair_value) . "'";
-						}
-					}
-	
-					if ($values_array) {
-						$value = '(' . implode(', ', $values_array) . ')';
-					}
-	
-					// @todo allow support for non IN operands with array of values.
-					// will have to do more silly joins.
-					$operand = 'IN';
-				} else if ($trimmed_operand == 'in') {
-					$value = "({$pair['value']})";
-				} else {
-					$value = "'" . $this->db->sanitizeString($pair['value']) . "'";
-				}
-	
-				$name = $this->db->sanitizeString($pair['name']);
-	
-				$return['joins'][] = "JOIN {$this->db->prefix}{$n_table} n_table{$i}
+                // certain operands can't work well with strings that can be interpreted as numbers
+                // for direct comparisons like IN, =, != we treat them as strings
+                // gt/lt comparisons need to stay unencapsulated because strings '5' > '15'
+                // see https://github.com/Elgg/Elgg/issues/7009
+                $num_safe_operands = ['>', '<', '>=', '<='];
+                $num_test_operand = trim(strtoupper($operand));
+	
+                if (is_numeric($pair['value']) && in_array($num_test_operand, $num_safe_operands)) {
+                    $value = $this->db->sanitizeString($pair['value']);
+                } else if (is_bool($pair['value'])) {
+                    $value = (int) $pair['value'];
+                } else if (is_array($pair['value'])) {
+                    $values_array = [];
+	
+                    foreach ($pair['value'] as $pair_value) {
+                        if (is_numeric($pair_value) && !in_array($num_test_operand, $num_safe_operands)) {
+                            $values_array[] = $this->db->sanitizeString($pair_value);
+                        } else {
+                            $values_array[] = "'" . $this->db->sanitizeString($pair_value) . "'";
+                        }
+                    }
+	
+                    if ($values_array) {
+                        $value = '(' . implode(', ', $values_array) . ')';
+                    }
+	
+                    // @todo allow support for non IN operands with array of values.
+                    // will have to do more silly joins.
+                    $operand = 'IN';
+                } else if ($trimmed_operand == 'in') {
+                    $value = "({$pair['value']})";
+                } else {
+                    $value = "'" . $this->db->sanitizeString($pair['value']) . "'";
+                }
+	
+                $name = $this->db->sanitizeString($pair['name']);
+	
+                $return['joins'][] = "JOIN {$this->db->prefix}{$n_table} n_table{$i}
 					on {$e_table}.guid = n_table{$i}.entity_guid";
 					
-				$pair_wheres[] = "(n_table{$i}.name = '$name' AND {$pair_binary}n_table{$i}.value
+                $pair_wheres[] = "(n_table{$i}.name = '$name' AND {$pair_binary}n_table{$i}.value
 					$operand $value AND $access)";
 	
-				$i++;
-			}
-	
-			if ($where = implode(" $pair_operator ", $pair_wheres)) {
-				$wheres[] = "($where)";
-			}
-		}
-	
-		// add owner_guids
-		if ($owner_guids) {
-			if (is_array($owner_guids)) {
-				$sanitised = array_map('sanitise_int', $owner_guids);
-				$owner_str = implode(',', $sanitised);
-			} else {
-				$owner_str = (int) $owner_guids;
-			}
-	
-			$wheres[] = "(n_table.owner_guid IN ($owner_str))";
-		}
-	
-		if ($where = implode(' AND ', $wheres)) {
-			$return['wheres'][] = "($where)";
-		}
-	
-		if (is_array($order_by_metadata)) {
-			if ((count($order_by_metadata) > 0) && !isset($order_by_metadata[0])) {
-				// singleton, so fix
-				$order_by_metadata = [$order_by_metadata];
-			}
-			foreach ($order_by_metadata as $order_by) {
-				if (is_array($order_by) && isset($order_by['name'])) {
-					$name = $this->db->sanitizeString($order_by['name']);
-					if (isset($order_by['direction'])) {
-						$direction = $this->db->sanitizeString($order_by['direction']);
-					} else {
-						$direction = 'ASC';
-					}
-					$return['joins'][] = "JOIN {$this->db->prefix}{$n_table} n_table{$i}
+                $i++;
+            }
+	
+            if ($where = implode(" $pair_operator ", $pair_wheres)) {
+                $wheres[] = "($where)";
+            }
+        }
+	
+        // add owner_guids
+        if ($owner_guids) {
+            if (is_array($owner_guids)) {
+                $sanitised = array_map('sanitise_int', $owner_guids);
+                $owner_str = implode(',', $sanitised);
+            } else {
+                $owner_str = (int) $owner_guids;
+            }
+	
+            $wheres[] = "(n_table.owner_guid IN ($owner_str))";
+        }
+	
+        if ($where = implode(' AND ', $wheres)) {
+            $return['wheres'][] = "($where)";
+        }
+	
+        if (is_array($order_by_metadata)) {
+            if ((count($order_by_metadata) > 0) && !isset($order_by_metadata[0])) {
+                // singleton, so fix
+                $order_by_metadata = [$order_by_metadata];
+            }
+            foreach ($order_by_metadata as $order_by) {
+                if (is_array($order_by) && isset($order_by['name'])) {
+                    $name = $this->db->sanitizeString($order_by['name']);
+                    if (isset($order_by['direction'])) {
+                        $direction = $this->db->sanitizeString($order_by['direction']);
+                    } else {
+                        $direction = 'ASC';
+                    }
+                    $return['joins'][] = "JOIN {$this->db->prefix}{$n_table} n_table{$i}
 						on {$e_table}.guid = n_table{$i}.entity_guid";
 	
-					$access = _elgg_get_access_where_sql([
-						'table_alias' => "n_table{$i}",
-						'guid_column' => 'entity_guid',
-					]);
-	
-					$return['wheres'][] = "(n_table{$i}.name = '$name' AND $access)";
-					if (isset($order_by['as']) && $order_by['as'] == 'integer') {
-						$return['orders'][] = "CAST(n_table{$i}.value AS SIGNED) $direction";
-					} else {
-						$return['orders'][] = "n_table{$i}.value $direction";
-					}
-					$i++;
-				}
-			}
-		}
-	
-		return $return;
-	}
-	
-	/**
-	 * Get the URL for this metadata
-	 *
-	 * By default this links to the export handler in the current view.
-	 *
-	 * @param int $id Metadata ID
-	 *
-	 * @return mixed
-	 */
-	function getUrl($id) {
-		$extender = $this->get($id);
+                    $access = _elgg_get_access_where_sql([
+                        'table_alias' => "n_table{$i}",
+                        'guid_column' => 'entity_guid',
+                    ]);
+	
+                    $return['wheres'][] = "(n_table{$i}.name = '$name' AND $access)";
+                    if (isset($order_by['as']) && $order_by['as'] == 'integer') {
+                        $return['orders'][] = "CAST(n_table{$i}.value AS SIGNED) $direction";
+                    } else {
+                        $return['orders'][] = "n_table{$i}.value $direction";
+                    }
+                    $i++;
+                }
+            }
+        }
+	
+        return $return;
+    }
+	
+    /**
+     * Get the URL for this metadata
+     *
+     * By default this links to the export handler in the current view.
+     *
+     * @param int $id Metadata ID
+     *
+     * @return mixed
+     */
+    function getUrl($id) {
+        $extender = $this->get($id);
 
-		return $extender ? $extender->getURL() : false;
-	}
-	
-	/**
-	 * Mark entities with a particular type and subtype as having access permissions
-	 * that can be changed independently from their parent entity
-	 *
-	 * @param string $type    The type - object, user, etc
-	 * @param string $subtype The subtype; all subtypes by default
-	 *
-	 * @return void
-	 */
-	function registerMetadataAsIndependent($type, $subtype = '*') {
-		if (!isset($this->independents[$type])) {
-			$this->independents[$type] = [];
-		}
+        return $extender ? $extender->getURL() : false;
+    }
+	
+    /**
+     * Mark entities with a particular type and subtype as having access permissions
+     * that can be changed independently from their parent entity
+     *
+     * @param string $type    The type - object, user, etc
+     * @param string $subtype The subtype; all subtypes by default
+     *
+     * @return void
+     */
+    function registerMetadataAsIndependent($type, $subtype = '*') {
+        if (!isset($this->independents[$type])) {
+            $this->independents[$type] = [];
+        }
 		
-		$this->independents[$type][$subtype] = true;
-	}
-	
-	/**
-	 * Determines whether entities of a given type and subtype should not change
-	 * their metadata in line with their parent entity
-	 *
-	 * @param string $type    The type - object, user, etc
-	 * @param string $subtype The entity subtype
-	 *
-	 * @return bool
-	 */
-	function isMetadataIndependent($type, $subtype) {
-		if (empty($this->independents[$type])) {
-			return false;
-		}
+        $this->independents[$type][$subtype] = true;
+    }
+	
+    /**
+     * Determines whether entities of a given type and subtype should not change
+     * their metadata in line with their parent entity
+     *
+     * @param string $type    The type - object, user, etc
+     * @param string $subtype The entity subtype
+     *
+     * @return bool
+     */
+    function isMetadataIndependent($type, $subtype) {
+        if (empty($this->independents[$type])) {
+            return false;
+        }
 
-		return !empty($this->independents[$type][$subtype])
-			|| !empty($this->independents[$type]['*']);
-	}
-	
-	/**
-	 * When an entity is updated, resets the access ID on all of its child metadata
-	 *
-	 * @param string      $event       The name of the event
-	 * @param string      $object_type The type of object
-	 * @param \ElggEntity $object      The entity itself
-	 *
-	 * @return true
-	 * @access private Set as private in 1.9.0
-	 */
-	function handleUpdate($event, $object_type, $object) {
-		if ($object instanceof \ElggEntity) {
-			if (!$this->isMetadataIndependent($object->getType(), $object->getSubtype())) {
-				$access_id = (int) $object->access_id;
-				$guid = (int) $object->getGUID();
-				$query = "update {$this->table} set access_id = {$access_id} where entity_guid = {$guid}";
-				$this->db->updateData($query);
-			}
-		}
-		return true;
-	}
+        return !empty($this->independents[$type][$subtype])
+            || !empty($this->independents[$type]['*']);
+    }
+	
+    /**
+     * When an entity is updated, resets the access ID on all of its child metadata
+     *
+     * @param string      $event       The name of the event
+     * @param string      $object_type The type of object
+     * @param \ElggEntity $object      The entity itself
+     *
+     * @return true
+     * @access private Set as private in 1.9.0
+     */
+    function handleUpdate($event, $object_type, $object) {
+        if ($object instanceof \ElggEntity) {
+            if (!$this->isMetadataIndependent($object->getType(), $object->getSubtype())) {
+                $access_id = (int) $object->access_id;
+                $guid = (int) $object->getGUID();
+                $query = "update {$this->table} set access_id = {$access_id} where entity_guid = {$guid}";
+                $this->db->updateData($query);
+            }
+        }
+        return true;
+    }
 	
 }