All line endings are now Unix-style.

git-svn-id: https://code.elgg.org/elgg/trunk@3451 36083f99-b078-4883-b0ff-0f9b5a30f544

1 files changed, 910 insertions, 910 deletions

diff --git a/engine/lib/metadata.php b/engine/lib/metadata.php
index 9aa033061..c6e5db4cd 100644
--- a/engine/lib/metadata.php
+++ b/engine/lib/metadata.php
@@ -1,912 +1,912 @@
-<?php

-	/**

-	 * Elgg metadata

-	 * Functions to manage object metadata.

-	 * 

-	 * @package Elgg

-	 * @subpackage Core

+<?php
+	/**
+	 * Elgg metadata
+	 * Functions to manage object metadata.
+	 * 
+	 * @package Elgg
+	 * @subpackage Core
 
-	 * @author Curverider Ltd <info@elgg.com>

+	 * @author Curverider Ltd <info@elgg.com>
 
-	 * @link http://elgg.org/

-	 */

-

-	/**

-	 * ElggMetadata

-	 * This class describes metadata that can be attached to ElggEntities.

-	 * 

-	 * @author Curverider Ltd <info@elgg.com>

-	 * @package Elgg

-	 * @subpackage Core

-	 */

-	class ElggMetadata extends ElggExtender

-	{

-			

-		/**

-		 * Construct a new site object, optionally from a given id value or row.

-		 *

-		 * @param mixed $id

-		 */

-		function __construct($id = null) 

-		{

-			$this->attributes = array();

-			

-			if (!empty($id)) {

-				

-				if ($id instanceof stdClass)

-					$metadata = $id; // Create from db row

-				else

-					$metadata = get_metadata($id);	

-				

-				if ($metadata) {

-					$objarray = (array) $metadata;

-					foreach($objarray as $key => $value) {

-						$this->attributes[$key] = $value;

-					}

-					$this->attributes['type'] = "metadata";

-				}

-			}

-		}

-		

-		/**

-		 * Class member get overloading

-		 *

-		 * @param string $name

-		 * @return mixed

-		 */

-		function __get($name) {

-			return $this->get($name);

-		}

-		

-		/**

-		 * Class member set overloading

-		 *

-		 * @param string $name

-		 * @param mixed $value

-		 * @return mixed

-		 */

-		function __set($name, $value) {

-			return $this->set($name, $value);

-		}

-

-		/**

-		 * Determines whether or not the user can edit this piece of metadata

-		 *

-		 * @return true|false Depending on permissions

-		 */

-		function canEdit() {

-			

-			if ($entity = get_entity($this->get('entity_guid'))) {

-				return $entity->canEditMetadata($this);

-			}

-			return false;

-			

-		}

-		

-		/**

-		 * Save matadata object

-		 *

-		 * @return int the metadata object id

-		 */

-		function save()

-		{

-			if ($this->id > 0)

-				return update_metadata($this->id, $this->name, $this->value, $this->value_type, $this->owner_guid, $this->access_id);

-			else

-			{ 

-				$this->id = create_metadata($this->entity_guid, $this->name, $this->value, $this->value_type, $this->owner_guid, $this->access_id);

-				if (!$this->id) throw new IOException(sprintf(elgg_new('IOException:UnableToSaveNew'), get_class()));

-				return $this->id;

-			}

-			

-		}

-		

-		/**

-		 * Delete a given metadata.

-		 */

-		function delete() 

-		{ 

-			return delete_metadata($this->id); 

-		}

-		

-		/**

-		 * Get a url for this item of metadata.

-		 *

-		 * @return string

-		 */

-		public function getURL() { return get_metadata_url($this->id); }

-	

-		// SYSTEM LOG INTERFACE ////////////////////////////////////////////////////////////

-

-		/**

-		 * For a given ID, return the object associated with it.

-		 * This is used by the river functionality primarily.

-		 * This is useful for checking access permissions etc on objects.

-		 */

-		public function getObjectFromID($id) { return get_metadata($id); }

-	}

-

-	/**

-	 * Convert a database row to a new ElggMetadata

-	 *

-	 * @param stdClass $row

-	 * @return stdClass or ElggMetadata

-	 */

-	function row_to_elggmetadata($row) 

-	{

-		if (!($row instanceof stdClass))

-			return $row;

-			

-		return new ElggMetadata($row);

-	}

-

-			

-	/**

-	 * Get a specific item of metadata.

-	 * 

-	 * @param $id int The item of metadata being retrieved.

-	 */

-	function get_metadata($id)

-	{

-		global $CONFIG;

-

-		$id = (int)$id;

-		$access = get_access_sql_suffix("e");

-		$md_access = get_access_sql_suffix("m");

-

-		return row_to_elggmetadata(get_data_row("SELECT m.*, n.string as name, v.string as value from {$CONFIG->dbprefix}metadata m JOIN {$CONFIG->dbprefix}entities e on e.guid = m.entity_guid JOIN {$CONFIG->dbprefix}metastrings v on m.value_id = v.id JOIN {$CONFIG->dbprefix}metastrings n on m.name_id = n.id where m.id=$id and $access and $md_access"));

-	}

-	

-	/**

-	 * Removes metadata on an entity with a particular name, optionally with a given value.

-	 *

-	 * @param int $entity_guid The entity GUID

-	 * @param string $name The name of the metadata

-	 * @param string $value The optional value of the item (useful for removing a single item in a multiple set)

-	 * @return true|false Depending on success

-	 */

-	function remove_metadata($entity_guid, $name, $value = "") {

-		

-		global $CONFIG;

-		$entity_guid = (int) $entity_guid;

-		$name = sanitise_string($name);

-		$value = sanitise_string($value);

-

-		$query = "SELECT * from {$CONFIG->dbprefix}metadata WHERE entity_guid = $entity_guid and name_id=" . add_metastring($name);

-		if ($value!="")

-			$query .= " and value_id=" . add_metastring($value);

-		

-		if ($existing = get_data($query)) {

-			foreach($existing as $ex)

-				delete_metadata($ex->id);

-			return true;

-		}

-		return false;

-		

-	}

-	

-	/**

-	 * Create a new metadata object, or update an existing one.

-	 *

-	 * @param int $entity_guid

-	 * @param string $name

-	 * @param string $value

-	 * @param string $value_type

-	 * @param int $owner_guid

-	 * @param int $access_id

-	 * @param bool $allow_multiple

-	 */

-	function create_metadata($entity_guid, $name, $value, $value_type, $owner_guid, $access_id = ACCESS_PRIVATE, $allow_multiple = false)

-	{

-		global $CONFIG;

-

-		$entity_guid = (int)$entity_guid;

-		//$name = sanitise_string(trim($name));

-		//$value = sanitise_string(trim($value));

-		$value_type = detect_extender_valuetype($value, sanitise_string(trim($value_type)));

-		$time = time();		

-		$owner_guid = (int)$owner_guid;

-		$allow_multiple = (boolean)$allow_multiple;

-		

-		if ($owner_guid==0) $owner_guid = get_loggedin_userid();

-		

-		$access_id = (int)$access_id;

-

-		$id = false;

-	

-		$existing = get_data_row("SELECT * from {$CONFIG->dbprefix}metadata WHERE entity_guid = $entity_guid and name_id=" . add_metastring($name) . " limit 1");

-		if (($existing) && (!$allow_multiple) && (isset($value))) 

-		{ 

-			$id = $existing->id;

-			$result = update_metadata($id, $name, $value, $value_type, $owner_guid, $access_id);

-			

-			if (!$result) return false;

-		}

-		else if (isset($value))

-		{

-			// Support boolean types

-			if (is_bool($value)) {

-				if ($value)

-					$value = 1;

-				else

-					$value = 0;

-			}

-			

-			// Add the metastrings

-			$value = add_metastring($value);

-			if (!$value) return false;

-			

-			$name = add_metastring($name);

-			if (!$name) return false;

-			

-			// If ok then add it

-			$id = insert_data("INSERT into {$CONFIG->dbprefix}metadata (entity_guid, name_id, value_id, value_type, owner_guid, time_created, access_id) VALUES ($entity_guid, '$name','$value','$value_type', $owner_guid, $time, $access_id)");

-			

-			if ($id!==false) {

-				$obj = get_metadata($id);

-				if (trigger_elgg_event('create', 'metadata', $obj)) {

-					return true;

-				} else {

-					delete_metadata($id);

-				}

-			}

-			

-		} else if ($existing) {

-// TODO: Check... are you sure you meant to do this Ben? :)			

-			$id = $existing->id;

-			delete_metadata($id);

-			

-		}

-		

-		return $id;

-	}

-	

-	/**

-	 * Update an item of metadata.

-	 *

-	 * @param int $id

-	 * @param string $name

-	 * @param string $value

-	 * @param string $value_type

-	 * @param int $owner_guid

-	 * @param int $access_id

-	 */

-	function update_metadata($id, $name, $value, $value_type, $owner_guid, $access_id)

-	{

-		global $CONFIG;

-

-		$id = (int)$id;

-

-		if (!$md = get_metadata($id)) return false;	

-		if (!$md->canEdit()) return false;

-

-		// If memcached then we invalidate the cache for this entry

-		static $metabyname_memcache;

-		if ((!$metabyname_memcache) && (is_memcache_available()))

-			$metabyname_memcache = new ElggMemcache('metabyname_memcache');

-		if ($metabyname_memcache) $metabyname_memcache->delete("{$md->entity_guid}:{$md->name_id}");

-		

-		//$name = sanitise_string(trim($name));

-		//$value = sanitise_string(trim($value));

-		$value_type = detect_extender_valuetype($value, sanitise_string(trim($value_type)));

-		

-		$owner_guid = (int)$owner_guid;

-		if ($owner_guid==0) $owner_guid = get_loggedin_userid();

-		

-		$access_id = (int)$access_id;

-		

-		$access = get_access_sql_suffix();

-		

-		// Support boolean types (as integers)

-		if (is_bool($value)) {

-			if ($value)

-				$value = 1;

-			else

-				$value = 0;

-		}

-		

-		// Add the metastring

-		$value = add_metastring($value);

-		if (!$value) return false;

-		

-		$name = add_metastring($name);

-		if (!$name) return false;

-

-				// If ok then add it

-		$result = update_data("UPDATE {$CONFIG->dbprefix}metadata set value_id='$value', value_type='$value_type', access_id=$access_id, owner_guid=$owner_guid where id=$id and name_id='$name'");

-		if ($result!==false) {

-			$obj = get_metadata($id);

-			if (trigger_elgg_event('update', 'metadata', $obj)) {

-				return true;

-			} else {

-				delete_metadata($id);

-			}

-		}

-			

-		return $result;

-	}

-	

-	/**

-	 * This function creates metadata from an associative array of "key => value" pairs.

-	 * 

-	 * @param int $entity_guid

-	 * @param string $name_and_values

-	 * @param string $value_type

-	 * @param int $owner_guid

-	 * @param int $access_id

-	 * @param bool $allow_multiple

-	 */

-	function create_metadata_from_array($entity_guid, array $name_and_values, $value_type, $owner_guid, $access_id = ACCESS_PRIVATE, $allow_multiple = false)

-	{

-		foreach ($name_and_values as $k => $v)

-			if (!create_metadata($entity_guid, $k, $v, $value_type, $owner_guid, $access_id, $allow_multiple)) return false;

-		

-		return true;

-	}

-	

-	/**

-	 * Delete an item of metadata, where the current user has access.

-	 * 

-	 * @param $id int The item of metadata to delete.

-	 */

-	function delete_metadata($id)

-	{

-		global $CONFIG;

-

-		$id = (int)$id;

-		$metadata = get_metadata($id);

-		

-		if ($metadata) {

-			// Tidy up if memcache is enabled.

-			static $metabyname_memcache;

-			if ((!$metabyname_memcache) && (is_memcache_available()))

-				$metabyname_memcache = new ElggMemcache('metabyname_memcache');

-			if ($metabyname_memcache) $metabyname_memcache->delete("{$metadata->entity_guid}:{$metadata->name_id}");

-			

-			if (($metadata->canEdit()) && (trigger_elgg_event('delete', 'metadata', $metadata)))

-				return delete_data("DELETE from {$CONFIG->dbprefix}metadata where id=$id");

-		}

-		

-		return false;

-	}

-	

-	/**

-	 * Return the metadata values that match your query.

-	 * 

-	 * @param string $meta_name

-	 * @return mixed either a value, an array of ElggMetadata or false.

-	 */

-	function get_metadata_byname($entity_guid,  $meta_name)

-	{

-		global $CONFIG;

-	

-		$meta_name = get_metastring_id($meta_name);

-		

-		if (empty($meta_name)) return false;

-		

-		$entity_guid = (int)$entity_guid;

-		$access = get_access_sql_suffix("e");

-		$md_access = get_access_sql_suffix("m");

-		

-		// If memcache is available then cache this (cache only by name for now since this is the most common query)

-		$meta = null;

-		static $metabyname_memcache;

-		if ((!$metabyname_memcache) && (is_memcache_available()))

-			$metabyname_memcache = new ElggMemcache('metabyname_memcache');

-		if ($metabyname_memcache) $meta = $metabyname_memcache->load("{$entity_guid}:{$meta_name}");

-		if ($meta) return $meta;	

-

-		$result = get_data("SELECT m.*, n.string as name, v.string as value from {$CONFIG->dbprefix}metadata m JOIN {$CONFIG->dbprefix}entities e ON e.guid = m.entity_guid JOIN {$CONFIG->dbprefix}metastrings v on m.value_id = v.id JOIN {$CONFIG->dbprefix}metastrings n on m.name_id = n.id where m.entity_guid=$entity_guid and m.name_id='$meta_name' and $access and $md_access", "row_to_elggmetadata");

-		if (!$result) 

-			return false;

-			

-		// Cache if memcache available

-		if ($metabyname_memcache)

-		{ 

-			if (count($result) == 1) $r = $result[0]; else $r = $result;

-			$metabyname_memcache->setDefaultExpiry(3600); // This is a bit of a hack - we shorten the expiry on object metadata so that it'll be gone in an hour. This means that deletions and more importantly updates will filter through eventually.

-			$metabyname_memcache->save("{$entity_guid}:{$meta_name}", $r);

-			

-		}

-		if (count($result) == 1)

-			return $result[0];

-			

-		return $result;

-	}

-	

-	/**

-	 * Return all the metadata for a given GUID.

-	 * 

-	 * @param int $entity_guid

-	 */

-	function get_metadata_for_entity($entity_guid)

-	{

-		global $CONFIG;

-	

-		$entity_guid = (int)$entity_guid;

-		$access = get_access_sql_suffix("e");

-		$md_access = get_access_sql_suffix("m");

-		

-		return get_data("SELECT m.*, n.string as name, v.string as value from {$CONFIG->dbprefix}metadata m JOIN {$CONFIG->dbprefix}entities e ON e.guid = m.entity_guid JOIN {$CONFIG->dbprefix}metastrings v on m.value_id = v.id JOIN {$CONFIG->dbprefix}metastrings n on m.name_id = n.id where m.entity_guid=$entity_guid and $access and $md_access", "row_to_elggmetadata");

-	}

-

-	/**

-	 * Get the metadata where the entities they are referring to match a given criteria.

-	 * 

-	 * @param mixed $meta_name 

-	 * @param mixed $meta_value

-	 * @param string $entity_type The type of entity to look for, eg 'site' or 'object'

-	 * @param string $entity_subtype The subtype of the entity.

-	 * @param int $limit 

-	 * @param int $offset

-	 * @param string $order_by Optional ordering.

-	 * @param int $site_guid The site to get entities for. Leave as 0 (default) for the current site; -1 for all sites.

-	 */

-	function find_metadata($meta_name = "", $meta_value = "", $entity_type = "", $entity_subtype = "", $limit = 10, $offset = 0, $order_by = "", $site_guid = 0)

-	{

-		global $CONFIG;

-		

-		$meta_n = get_metastring_id($meta_name);

-		$meta_v = get_metastring_id($meta_value);

-		

-		$entity_type = sanitise_string($entity_type);

-		$entity_subtype = get_subtype_id($entity_type, $entity_subtype);

-		$limit = (int)$limit;

-		$offset = (int)$offset;

-		if ($order_by == "") $order_by = "e.time_created desc";

-		$order_by = sanitise_string($order_by);

-		$site_guid = (int) $site_guid;

-		if ($site_guid == 0)

-			$site_guid = $CONFIG->site_guid;

-			

-			

-		$where = array();

-		

-		if ($entity_type!="")

-			$where[] = "e.type='$entity_type'";

-		if ($entity_subtype)

-			$where[] = "e.subtype=$entity_subtype";

-		if ($meta_name!="") {

-			if (!$meta_v) return false; // The value is set, but we didn't get a value... so something went wrong.

-			$where[] = "m.name_id='$meta_n'";

-		}

-		if ($meta_value!="") {

-			if (!$meta_v) return false; // The value is set, but we didn't get a value... so something went wrong.

-			$where[] = "m.value_id='$meta_v'";

-		}

-		if ($site_guid > 0)

-			$where[] = "e.site_guid = {$site_guid}";

-		

-		$query = "SELECT m.*, n.string as name, v.string as value from {$CONFIG->dbprefix}entities e JOIN {$CONFIG->dbprefix}metadata m on e.guid = m.entity_guid JOIN {$CONFIG->dbprefix}metastrings v on m.value_id = v.id JOIN {$CONFIG->dbprefix}metastrings n on m.name_id = n.id where";

-		foreach ($where as $w)

-			$query .= " $w and ";

-		$query .= get_access_sql_suffix("e"); // Add access controls

-		$query .= ' and ' . get_access_sql_suffix("m"); // Add access controls

-		$query .= " order by $order_by limit $offset, $limit"; // Add order and limit

-

-		return get_data($query, "row_to_elggmetadata");

-	}

-	

-	/**

-	 * Return a list of entities based on the given search criteria.

-	 * 

-	 * @param mixed $meta_name 

-	 * @param mixed $meta_value

-	 * @param string $entity_type The type of entity to look for, eg 'site' or 'object'

-	 * @param string $entity_subtype The subtype of the entity.

-	 * @param int $limit 

-	 * @param int $offset

-	 * @param string $order_by Optional ordering.

-	 * @param int $site_guid The site to get entities for. Leave as 0 (default) for the current site; -1 for all sites.

-	 * @param true|false $count If set to true, returns the total number of entities rather than a list. (Default: false)

-	 * 

-	 * @return int|array A list of entities, or a count if $count is set to true

-	 */

-	function get_entities_from_metadata($meta_name, $meta_value = "", $entity_type = "", $entity_subtype = "", $owner_guid = 0, $limit = 10, $offset = 0, $order_by = "", $site_guid = 0, $count = false)

-	{

-		global $CONFIG;

-		

-		$meta_n = get_metastring_id($meta_name);

-		$meta_v = get_metastring_id($meta_value);

-			

-		$entity_type = sanitise_string($entity_type);

-		$entity_subtype = get_subtype_id($entity_type, $entity_subtype);

-		$limit = (int)$limit;

-		$offset = (int)$offset;

-		if ($order_by == "") 

-			$order_by = "e.time_created desc";

-		else

-			$order_by = "e.time_created, {$order_by}";

-		$order_by = sanitise_string($order_by);

-		$site_guid = (int) $site_guid;

-		if ((is_array($owner_guid) && (count($owner_guid)))) {

-			foreach($owner_guid as $key => $guid) {

-				$owner_guid[$key] = (int) $guid;

-			}

-		} else {

-			$owner_guid = (int) $owner_guid;

-		}

-		if ($site_guid == 0)

-			$site_guid = $CONFIG->site_guid;

-			

-		//$access = get_access_list();

-			

-		$where = array();

-		

-		if ($entity_type!=="")

-			$where[] = "e.type='$entity_type'";

-		if ($entity_subtype)

-			$where[] = "e.subtype=$entity_subtype";

-		if ($meta_name!=="")

-			$where[] = "m.name_id='$meta_n'";

-		if ($meta_value!=="")

-			$where[] = "m.value_id='$meta_v'";

-		if ($site_guid > 0)

-			$where[] = "e.site_guid = {$site_guid}";

-		if (is_array($owner_guid)) {

-			$where[] = "e.container_guid in (".implode(",",$owner_guid).")";

-		} else if ($owner_guid > 0)

-			$where[] = "e.container_guid = {$owner_guid}";

-		

-		if (!$count) {

-			$query = "SELECT distinct e.* "; 

-		} else {

-			$query = "SELECT count(distinct e.guid) as total ";

-		}

-			

-		$query .= "from {$CONFIG->dbprefix}entities e JOIN {$CONFIG->dbprefix}metadata m on e.guid = m.entity_guid where";

-		foreach ($where as $w)

-			$query .= " $w and ";

-		$query .= get_access_sql_suffix("e"); // Add access controls

-		$query .= ' and ' . get_access_sql_suffix("m"); // Add access controls

-		

-		if (!$count) {

-			$query .= " order by $order_by limit $offset, $limit"; // Add order and limit

-			return get_data($query, "entity_row_to_elggstar");

-		} else {

-			if ($row = get_data_row($query))

-				return $row->total;

-		}

-		return false;

-	}

-	

-	/**

-	 * Return a list of entities suitable for display based on the given search criteria.

-	 * 

-	 * @see elgg_view_entity_list

-	 * 

-	 * @param mixed $meta_name Metadata name to search on

-	 * @param mixed $meta_value The value to match, optionally

-	 * @param string $entity_type The type of entity to look for, eg 'site' or 'object'

-	 * @param string $entity_subtype The subtype of the entity

-	 * @param int $limit Number of entities to display per page

-	 * @param true|false $fullview Whether or not to display the full view (default: true)

-	 * @param true|false $viewtypetoggle Whether or not to allow users to toggle to the gallery view. Default: true

-	 * @param true|false $pagination Display pagination? Default: true

-	 * 

-	 * @return string A list of entities suitable for display

-	 */

-	function list_entities_from_metadata($meta_name, $meta_value = "", $entity_type = "", $entity_subtype = "", $owner_guid = 0, $limit = 10, $fullview = true, $viewtypetoggle = true, $pagination = true) {

-		

-		$offset = (int) get_input('offset');

-		$limit = (int) $limit;

-		$count = get_entities_from_metadata($meta_name, $meta_value, $entity_type, $entity_subtype, $owner_guid, $limit, $offset, "", 0, true);

-		$entities = get_entities_from_metadata($meta_name, $meta_value, $entity_type, $entity_subtype, $owner_guid, $limit, $offset, "", 0, false);

-		

-		return elgg_view_entity_list($entities, $count, $offset, $limit, $fullview, $viewtypetoggle, $pagination);

-		

-	}

-

-	/**

-	 * Returns a list of entities based on the given search criteria.

-	 *

-	 * @param array $meta_array Array of 'name' => 'value' pairs

-	 * @param string $entity_type The type of entity to look for, eg 'site' or 'object'

-	 * @param string $entity_subtype The subtype of the entity.

-	 * @param int $limit 

-	 * @param int $offset

-	 * @param string $order_by Optional ordering.

-	 * @param int $site_guid The site to get entities for. Leave as 0 (default) for the current site; -1 for all sites.

-	 * @param true|false $count If set to true, returns the total number of entities rather than a list. (Default: false)

-	 * @param string $meta_array_operator Operator used for joining the metadata array together

-	 * @return int|array List of ElggEntities, or the total number if count is set to false

-	 */

-	function get_entities_from_metadata_multi($meta_array, $entity_type = "", $entity_subtype = "", $owner_guid = 0, $limit = 10, $offset = 0, $order_by = "", $site_guid = 0, $count = false, $meta_array_operator = 'and')

-	{

-		global $CONFIG;

-		

-		if (!is_array($meta_array) || sizeof($meta_array) == 0) {

-			return false;

-		}

-		

-		$where = array();

-		

-		$mindex = 1;

-		$join = "";

-		$metawhere = array();

-		$meta_array_operator = sanitise_string($meta_array_operator);

-		foreach($meta_array as $meta_name => $meta_value) {

-			$meta_n = get_metastring_id($meta_name);

-			$meta_v = get_metastring_id($meta_value);

-			$join .= " JOIN {$CONFIG->dbprefix}metadata m{$mindex} on e.guid = m{$mindex}.entity_guid "; 

-			/*if ($meta_name!=="")

-				$where[] = "m{$mindex}.name_id='$meta_n'";

-			if ($meta_value!=="")

-				$where[] = "m{$mindex}.value_id='$meta_v'";*/

-			$metawhere[] = "(m{$mindex}.name_id='$meta_n' AND m{$mindex}.value_id='$meta_v')";

-			$mindex++;

-		}

-		$where[] = "(".implode($meta_array_operator, $metawhere).")";

-			

-		$entity_type = sanitise_string($entity_type);

-		$entity_subtype = get_subtype_id($entity_type, $entity_subtype);

-		$limit = (int)$limit;

-		$offset = (int)$offset;

-		if ($order_by == "") $order_by = "e.time_created desc";

-		$order_by = sanitise_string($order_by);

-		if ((is_array($owner_guid) && (count($owner_guid)))) {

-			foreach($owner_guid as $key => $guid) {

-				$owner_guid[$key] = (int) $guid;

-			}

-		} else {

-			$owner_guid = (int) $owner_guid;

-		}

-		

-		$site_guid = (int) $site_guid;

-		if ($site_guid == 0)

-			$site_guid = $CONFIG->site_guid;

-			

-		//$access = get_access_list();

-		

-		if ($entity_type!="")

-			$where[] = "e.type = '{$entity_type}'";

-		if ($entity_subtype)

-			$where[] = "e.subtype = {$entity_subtype}";

-		if ($site_guid > 0)

-			$where[] = "e.site_guid = {$site_guid}";

-		if (is_array($owner_guid)) {

-			$where[] = "e.container_guid in (".implode(",",$owner_guid).")";

-		} else if ($owner_guid > 0)

-			$where[] = "e.container_guid = {$owner_guid}";

-		//if ($owner_guid > 0)

-		//	$where[] = "e.container_guid = {$owner_guid}";

-		

-		if ($count) {

-			$query = "SELECT count(distinct e.guid) as total ";

-		} else {

-			$query = "SELECT distinct e.* "; 

-		}

-			

-		$query .= " from {$CONFIG->dbprefix}entities e {$join} where";

-		foreach ($where as $w)

-			$query .= " $w and ";

-		$query .= get_access_sql_suffix("e"); // Add access controls

-	

-		$mindex = 1;

-		foreach($meta_array as $meta_name => $meta_value) {

-			$query .= ' and ' . get_access_sql_suffix("m{$mindex}"); // Add access controls

-			$mindex++;

-		}

-		

-		if (!$count) {

-			$query .= " order by $order_by limit $offset, $limit"; // Add order and limit

-			return get_data($query, "entity_row_to_elggstar");

-		} else {

-			if ($count = get_data_row($query)) {

-				return $count->total;

-			}

-		}

-		return false;

-	}

-	

-	/**

-	 * Returns a viewable list of entities based on the given search criteria.

-	 *

-	 * @see elgg_view_entity_list

-	 * 

-	 * @param array $meta_array Array of 'name' => 'value' pairs

-	 * @param string $entity_type The type of entity to look for, eg 'site' or 'object'

-	 * @param string $entity_subtype The subtype of the entity.

-	 * @param int $limit 

-	 * @param int $offset

-	 * @param string $order_by Optional ordering.

-	 * @param true|false $fullview Whether or not to display the full view (default: true)

-	 * @param true|false $viewtypetoggle Whether or not to allow users to toggle to the gallery view. Default: true

-	 * @param true|false $pagination Display pagination? Default: true

-	 * @return string List of ElggEntities suitable for display

-	 */

-	function list_entities_from_metadata_multi($meta_array, $entity_type = "", $entity_subtype = "", $owner_guid = 0, $limit = 10, $fullview = true, $viewtypetoggle = true, $pagination = true) {

-		

-		$offset = (int) get_input('offset');

-		$limit = (int) $limit;

-		$count = get_entities_from_metadata_multi($meta_array, $entity_type, $entity_subtype, $owner_guid, $limit, $offset, "", $site_guid, true);

-		$entities = get_entities_from_metadata_multi($meta_array, $entity_type, $entity_subtype, $owner_guid, $limit, $offset, "", $site_guid, false);

-	

-		return elgg_view_entity_list($entities, $count, $offset, $limit, $fullview, $viewtypetoggle, $pagination);

-		

-	}

-	

-	/**

-	 * Clear all the metadata for a given entity, assuming you have access to that metadata.

-	 * 

-	 * @param int $guid

-	 */

-	function clear_metadata($entity_guid)

-	{

-		global $CONFIG;

-		

-		$entity_guid = (int)$entity_guid;

-		if ($entity = get_entity($entity_guid)) {

-			if ($entity->canEdit())

-				return delete_data("DELETE from {$CONFIG->dbprefix}metadata where entity_guid={$entity_guid}");

-		}

-		return false;

-	}

-	

-	/**

-	 * Clear all annotations belonging to a given owner_guid

-	 *

-	 * @param int $owner_guid The owner

-	 */

-	function clear_metadata_by_owner($owner_guid)

-	{

-		global $CONFIG;

-		

-		$owner_guid = (int)$owner_guid;

-		

-		$metas = get_data("SELECT id from {$CONFIG->dbprefix}metadata WHERE owner_guid=$owner_guid");

-		$deleted = 0;

-		

-		foreach ($metas as $id)

-		{

-			if (delete_metadata($id->id)) // Is this the best way?

-				$deleted++;

-		}

-		

-		return $deleted;

-	}

-	

-	/**

-	 * Handler called by trigger_plugin_hook on the "export" event.

-	 */

-	function export_metadata_plugin_hook($hook, $entity_type, $returnvalue, $params)

-	{

-		// Sanity check values

-		if ((!is_array($params)) && (!isset($params['guid'])))

-			throw new InvalidParameterException(elgg_echo('InvalidParameterException:GUIDNotForExport'));

-			

-		if (!is_array($returnvalue))

-			throw new InvalidParameterException(elgg_echo('InvalidParameterException:NonArrayReturnValue'));

-		

-		$guid = (int)$params['guid'];

-		$name = $params['name'];	

-		

-		$result = get_metadata_for_entity($guid); 

-				

-		if ($result)

-		{

-			foreach ($result as $r)

-				$returnvalue[] = $r->export();

-		}

-		

-		return $returnvalue;

-	}

-	

-	/**

-	 * Takes in a comma-separated string and returns an array of tags which have been trimmed and set to lower case

-	 *

-	 * @param string $string Comma-separated tag string

-	 * @return array|false An array of strings, or false on failure

-	 */

-	function string_to_tag_array($string) {

-		

-		if (is_string($string)) {

-			$ar = explode(",",$string);

-			$ar = array_map('trim', $ar); // trim blank spaces

-			$ar = array_map('elgg_strtolower', $ar); // make lower case : [Marcus Povey 20090605 - Using mb wrapper function using UTF8 safe function where available]

-			$ar = array_filter($ar, 'is_not_null'); // Remove null values

-			return $ar;

-		}

-		return false;

-		

-	}

-	

-	/**

-	 * Takes a metadata array (which has all kinds of properties) and turns it into a simple array of strings 

-	 *

-	 * @param array $array Metadata array

-	 * @return array Array of strings

-	 */

-	function metadata_array_to_values($array) {

-		

-		$valuearray = array();

-		

-		if (is_array($array)) {

-			foreach($array as $element) {

-				$valuearray[] = $element->value;

-			}

-		}

-		

-		return $valuearray;

-		

-	}

-	

-	/**

-	 * Get the URL for this item of metadata, by default this links to the export handler in the current view.

-	 *

-	 * @param int $id

-	 */

-	function get_metadata_url($id)

-	{

-		$id = (int)$id;

-		

-		if ($extender = get_metadata($id)) {

-			return get_extender_url($extender);	

-		} 

-		return 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

-	 */

-	function register_metadata_as_independent($type, $subtype = '*') {

-		global $CONFIG;

-		if (!isset($CONFIG->independents)) $CONFIG->independents = array();

-		$CONFIG->independents[$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 true|false

-	 */

-	function is_metadata_independent($type, $subtype) {

-		global $CONFIG;

-		if (empty($CONFIG->independents)) return false;

-		if (!empty($CONFIG->independents[$type][$subtype])

-			|| !empty($CONFIG->independents[$type]['*'])) return true;

-		return false;

-	}

-	

-	/**

-	 * 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

-	 */

-	function metadata_update($event, $object_type, $object) {

-		if ($object instanceof ElggEntity) {

-			if (!is_metadata_independent($object->getType(), $object->getSubtype())) {

-				global $CONFIG;

-				$access_id = (int) $object->access_id;

-				$guid = (int) $object->getGUID();

-				update_data("update {$CONFIG->dbprefix}metadata set access_id = {$access_id} where entity_guid = {$guid}");

-			}

-		}	

-		return true;	

-	}

-	

-	/**

-	 * Register a metadata url handler.

-	 *

-	 * @param string $function_name The function.

-	 * @param string $extender_name The name, default 'all'.

-	 */

-	function register_metadata_url_handler($function_name, $extender_name = "all") {

-		return register_extender_url_handler($function_name, 'metadata', $extender_name);

-	}

-		

-	/** Register the hook */

-	register_plugin_hook("export", "all", "export_metadata_plugin_hook", 2);

-	/** Call a function whenever an entity is updated **/

-	register_elgg_event_handler('update','all','metadata_update');

-	

-?>

+	 * @link http://elgg.org/
+	 */
+
+	/**
+	 * ElggMetadata
+	 * This class describes metadata that can be attached to ElggEntities.
+	 * 
+	 * @author Curverider Ltd <info@elgg.com>
+	 * @package Elgg
+	 * @subpackage Core
+	 */
+	class ElggMetadata extends ElggExtender
+	{
+			
+		/**
+		 * Construct a new site object, optionally from a given id value or row.
+		 *
+		 * @param mixed $id
+		 */
+		function __construct($id = null) 
+		{
+			$this->attributes = array();
+			
+			if (!empty($id)) {
+				
+				if ($id instanceof stdClass)
+					$metadata = $id; // Create from db row
+				else
+					$metadata = get_metadata($id);	
+				
+				if ($metadata) {
+					$objarray = (array) $metadata;
+					foreach($objarray as $key => $value) {
+						$this->attributes[$key] = $value;
+					}
+					$this->attributes['type'] = "metadata";
+				}
+			}
+		}
+		
+		/**
+		 * Class member get overloading
+		 *
+		 * @param string $name
+		 * @return mixed
+		 */
+		function __get($name) {
+			return $this->get($name);
+		}
+		
+		/**
+		 * Class member set overloading
+		 *
+		 * @param string $name
+		 * @param mixed $value
+		 * @return mixed
+		 */
+		function __set($name, $value) {
+			return $this->set($name, $value);
+		}
+
+		/**
+		 * Determines whether or not the user can edit this piece of metadata
+		 *
+		 * @return true|false Depending on permissions
+		 */
+		function canEdit() {
+			
+			if ($entity = get_entity($this->get('entity_guid'))) {
+				return $entity->canEditMetadata($this);
+			}
+			return false;
+			
+		}
+		
+		/**
+		 * Save matadata object
+		 *
+		 * @return int the metadata object id
+		 */
+		function save()
+		{
+			if ($this->id > 0)
+				return update_metadata($this->id, $this->name, $this->value, $this->value_type, $this->owner_guid, $this->access_id);
+			else
+			{ 
+				$this->id = create_metadata($this->entity_guid, $this->name, $this->value, $this->value_type, $this->owner_guid, $this->access_id);
+				if (!$this->id) throw new IOException(sprintf(elgg_new('IOException:UnableToSaveNew'), get_class()));
+				return $this->id;
+			}
+			
+		}
+		
+		/**
+		 * Delete a given metadata.
+		 */
+		function delete() 
+		{ 
+			return delete_metadata($this->id); 
+		}
+		
+		/**
+		 * Get a url for this item of metadata.
+		 *
+		 * @return string
+		 */
+		public function getURL() { return get_metadata_url($this->id); }
+	
+		// SYSTEM LOG INTERFACE ////////////////////////////////////////////////////////////
+
+		/**
+		 * For a given ID, return the object associated with it.
+		 * This is used by the river functionality primarily.
+		 * This is useful for checking access permissions etc on objects.
+		 */
+		public function getObjectFromID($id) { return get_metadata($id); }
+	}
+
+	/**
+	 * Convert a database row to a new ElggMetadata
+	 *
+	 * @param stdClass $row
+	 * @return stdClass or ElggMetadata
+	 */
+	function row_to_elggmetadata($row) 
+	{
+		if (!($row instanceof stdClass))
+			return $row;
+			
+		return new ElggMetadata($row);
+	}
+
+			
+	/**
+	 * Get a specific item of metadata.
+	 * 
+	 * @param $id int The item of metadata being retrieved.
+	 */
+	function get_metadata($id)
+	{
+		global $CONFIG;
+
+		$id = (int)$id;
+		$access = get_access_sql_suffix("e");
+		$md_access = get_access_sql_suffix("m");
+
+		return row_to_elggmetadata(get_data_row("SELECT m.*, n.string as name, v.string as value from {$CONFIG->dbprefix}metadata m JOIN {$CONFIG->dbprefix}entities e on e.guid = m.entity_guid JOIN {$CONFIG->dbprefix}metastrings v on m.value_id = v.id JOIN {$CONFIG->dbprefix}metastrings n on m.name_id = n.id where m.id=$id and $access and $md_access"));
+	}
+	
+	/**
+	 * Removes metadata on an entity with a particular name, optionally with a given value.
+	 *
+	 * @param int $entity_guid The entity GUID
+	 * @param string $name The name of the metadata
+	 * @param string $value The optional value of the item (useful for removing a single item in a multiple set)
+	 * @return true|false Depending on success
+	 */
+	function remove_metadata($entity_guid, $name, $value = "") {
+		
+		global $CONFIG;
+		$entity_guid = (int) $entity_guid;
+		$name = sanitise_string($name);
+		$value = sanitise_string($value);
+
+		$query = "SELECT * from {$CONFIG->dbprefix}metadata WHERE entity_guid = $entity_guid and name_id=" . add_metastring($name);
+		if ($value!="")
+			$query .= " and value_id=" . add_metastring($value);
+		
+		if ($existing = get_data($query)) {
+			foreach($existing as $ex)
+				delete_metadata($ex->id);
+			return true;
+		}
+		return false;
+		
+	}
+	
+	/**
+	 * Create a new metadata object, or update an existing one.
+	 *
+	 * @param int $entity_guid
+	 * @param string $name
+	 * @param string $value
+	 * @param string $value_type
+	 * @param int $owner_guid
+	 * @param int $access_id
+	 * @param bool $allow_multiple
+	 */
+	function create_metadata($entity_guid, $name, $value, $value_type, $owner_guid, $access_id = ACCESS_PRIVATE, $allow_multiple = false)
+	{
+		global $CONFIG;
+
+		$entity_guid = (int)$entity_guid;
+		//$name = sanitise_string(trim($name));
+		//$value = sanitise_string(trim($value));
+		$value_type = detect_extender_valuetype($value, sanitise_string(trim($value_type)));
+		$time = time();		
+		$owner_guid = (int)$owner_guid;
+		$allow_multiple = (boolean)$allow_multiple;
+		
+		if ($owner_guid==0) $owner_guid = get_loggedin_userid();
+		
+		$access_id = (int)$access_id;
+
+		$id = false;
+	
+		$existing = get_data_row("SELECT * from {$CONFIG->dbprefix}metadata WHERE entity_guid = $entity_guid and name_id=" . add_metastring($name) . " limit 1");
+		if (($existing) && (!$allow_multiple) && (isset($value))) 
+		{ 
+			$id = $existing->id;
+			$result = update_metadata($id, $name, $value, $value_type, $owner_guid, $access_id);
+			
+			if (!$result) return false;
+		}
+		else if (isset($value))
+		{
+			// Support boolean types
+			if (is_bool($value)) {
+				if ($value)
+					$value = 1;
+				else
+					$value = 0;
+			}
+			
+			// Add the metastrings
+			$value = add_metastring($value);
+			if (!$value) return false;
+			
+			$name = add_metastring($name);
+			if (!$name) return false;
+			
+			// If ok then add it
+			$id = insert_data("INSERT into {$CONFIG->dbprefix}metadata (entity_guid, name_id, value_id, value_type, owner_guid, time_created, access_id) VALUES ($entity_guid, '$name','$value','$value_type', $owner_guid, $time, $access_id)");
+			
+			if ($id!==false) {
+				$obj = get_metadata($id);
+				if (trigger_elgg_event('create', 'metadata', $obj)) {
+					return true;
+				} else {
+					delete_metadata($id);
+				}
+			}
+			
+		} else if ($existing) {
+// TODO: Check... are you sure you meant to do this Ben? :)			
+			$id = $existing->id;
+			delete_metadata($id);
+			
+		}
+		
+		return $id;
+	}
+	
+	/**
+	 * Update an item of metadata.
+	 *
+	 * @param int $id
+	 * @param string $name
+	 * @param string $value
+	 * @param string $value_type
+	 * @param int $owner_guid
+	 * @param int $access_id
+	 */
+	function update_metadata($id, $name, $value, $value_type, $owner_guid, $access_id)
+	{
+		global $CONFIG;
+
+		$id = (int)$id;
+
+		if (!$md = get_metadata($id)) return false;	
+		if (!$md->canEdit()) return false;
+
+		// If memcached then we invalidate the cache for this entry
+		static $metabyname_memcache;
+		if ((!$metabyname_memcache) && (is_memcache_available()))
+			$metabyname_memcache = new ElggMemcache('metabyname_memcache');
+		if ($metabyname_memcache) $metabyname_memcache->delete("{$md->entity_guid}:{$md->name_id}");
+		
+		//$name = sanitise_string(trim($name));
+		//$value = sanitise_string(trim($value));
+		$value_type = detect_extender_valuetype($value, sanitise_string(trim($value_type)));
+		
+		$owner_guid = (int)$owner_guid;
+		if ($owner_guid==0) $owner_guid = get_loggedin_userid();
+		
+		$access_id = (int)$access_id;
+		
+		$access = get_access_sql_suffix();
+		
+		// Support boolean types (as integers)
+		if (is_bool($value)) {
+			if ($value)
+				$value = 1;
+			else
+				$value = 0;
+		}
+		
+		// Add the metastring
+		$value = add_metastring($value);
+		if (!$value) return false;
+		
+		$name = add_metastring($name);
+		if (!$name) return false;
+
+				// If ok then add it
+		$result = update_data("UPDATE {$CONFIG->dbprefix}metadata set value_id='$value', value_type='$value_type', access_id=$access_id, owner_guid=$owner_guid where id=$id and name_id='$name'");
+		if ($result!==false) {
+			$obj = get_metadata($id);
+			if (trigger_elgg_event('update', 'metadata', $obj)) {
+				return true;
+			} else {
+				delete_metadata($id);
+			}
+		}
+			
+		return $result;
+	}
+	
+	/**
+	 * This function creates metadata from an associative array of "key => value" pairs.
+	 * 
+	 * @param int $entity_guid
+	 * @param string $name_and_values
+	 * @param string $value_type
+	 * @param int $owner_guid
+	 * @param int $access_id
+	 * @param bool $allow_multiple
+	 */
+	function create_metadata_from_array($entity_guid, array $name_and_values, $value_type, $owner_guid, $access_id = ACCESS_PRIVATE, $allow_multiple = false)
+	{
+		foreach ($name_and_values as $k => $v)
+			if (!create_metadata($entity_guid, $k, $v, $value_type, $owner_guid, $access_id, $allow_multiple)) return false;
+		
+		return true;
+	}
+	
+	/**
+	 * Delete an item of metadata, where the current user has access.
+	 * 
+	 * @param $id int The item of metadata to delete.
+	 */
+	function delete_metadata($id)
+	{
+		global $CONFIG;
+
+		$id = (int)$id;
+		$metadata = get_metadata($id);
+		
+		if ($metadata) {
+			// Tidy up if memcache is enabled.
+			static $metabyname_memcache;
+			if ((!$metabyname_memcache) && (is_memcache_available()))
+				$metabyname_memcache = new ElggMemcache('metabyname_memcache');
+			if ($metabyname_memcache) $metabyname_memcache->delete("{$metadata->entity_guid}:{$metadata->name_id}");
+			
+			if (($metadata->canEdit()) && (trigger_elgg_event('delete', 'metadata', $metadata)))
+				return delete_data("DELETE from {$CONFIG->dbprefix}metadata where id=$id");
+		}
+		
+		return false;
+	}
+	
+	/**
+	 * Return the metadata values that match your query.
+	 * 
+	 * @param string $meta_name
+	 * @return mixed either a value, an array of ElggMetadata or false.
+	 */
+	function get_metadata_byname($entity_guid,  $meta_name)
+	{
+		global $CONFIG;
+	
+		$meta_name = get_metastring_id($meta_name);
+		
+		if (empty($meta_name)) return false;
+		
+		$entity_guid = (int)$entity_guid;
+		$access = get_access_sql_suffix("e");
+		$md_access = get_access_sql_suffix("m");
+		
+		// If memcache is available then cache this (cache only by name for now since this is the most common query)
+		$meta = null;
+		static $metabyname_memcache;
+		if ((!$metabyname_memcache) && (is_memcache_available()))
+			$metabyname_memcache = new ElggMemcache('metabyname_memcache');
+		if ($metabyname_memcache) $meta = $metabyname_memcache->load("{$entity_guid}:{$meta_name}");
+		if ($meta) return $meta;	
+
+		$result = get_data("SELECT m.*, n.string as name, v.string as value from {$CONFIG->dbprefix}metadata m JOIN {$CONFIG->dbprefix}entities e ON e.guid = m.entity_guid JOIN {$CONFIG->dbprefix}metastrings v on m.value_id = v.id JOIN {$CONFIG->dbprefix}metastrings n on m.name_id = n.id where m.entity_guid=$entity_guid and m.name_id='$meta_name' and $access and $md_access", "row_to_elggmetadata");
+		if (!$result) 
+			return false;
+			
+		// Cache if memcache available
+		if ($metabyname_memcache)
+		{ 
+			if (count($result) == 1) $r = $result[0]; else $r = $result;
+			$metabyname_memcache->setDefaultExpiry(3600); // This is a bit of a hack - we shorten the expiry on object metadata so that it'll be gone in an hour. This means that deletions and more importantly updates will filter through eventually.
+			$metabyname_memcache->save("{$entity_guid}:{$meta_name}", $r);
+			
+		}
+		if (count($result) == 1)
+			return $result[0];
+			
+		return $result;
+	}
+	
+	/**
+	 * Return all the metadata for a given GUID.
+	 * 
+	 * @param int $entity_guid
+	 */
+	function get_metadata_for_entity($entity_guid)
+	{
+		global $CONFIG;
+	
+		$entity_guid = (int)$entity_guid;
+		$access = get_access_sql_suffix("e");
+		$md_access = get_access_sql_suffix("m");
+		
+		return get_data("SELECT m.*, n.string as name, v.string as value from {$CONFIG->dbprefix}metadata m JOIN {$CONFIG->dbprefix}entities e ON e.guid = m.entity_guid JOIN {$CONFIG->dbprefix}metastrings v on m.value_id = v.id JOIN {$CONFIG->dbprefix}metastrings n on m.name_id = n.id where m.entity_guid=$entity_guid and $access and $md_access", "row_to_elggmetadata");
+	}
+
+	/**
+	 * Get the metadata where the entities they are referring to match a given criteria.
+	 * 
+	 * @param mixed $meta_name 
+	 * @param mixed $meta_value
+	 * @param string $entity_type The type of entity to look for, eg 'site' or 'object'
+	 * @param string $entity_subtype The subtype of the entity.
+	 * @param int $limit 
+	 * @param int $offset
+	 * @param string $order_by Optional ordering.
+	 * @param int $site_guid The site to get entities for. Leave as 0 (default) for the current site; -1 for all sites.
+	 */
+	function find_metadata($meta_name = "", $meta_value = "", $entity_type = "", $entity_subtype = "", $limit = 10, $offset = 0, $order_by = "", $site_guid = 0)
+	{
+		global $CONFIG;
+		
+		$meta_n = get_metastring_id($meta_name);
+		$meta_v = get_metastring_id($meta_value);
+		
+		$entity_type = sanitise_string($entity_type);
+		$entity_subtype = get_subtype_id($entity_type, $entity_subtype);
+		$limit = (int)$limit;
+		$offset = (int)$offset;
+		if ($order_by == "") $order_by = "e.time_created desc";
+		$order_by = sanitise_string($order_by);
+		$site_guid = (int) $site_guid;
+		if ($site_guid == 0)
+			$site_guid = $CONFIG->site_guid;
+			
+			
+		$where = array();
+		
+		if ($entity_type!="")
+			$where[] = "e.type='$entity_type'";
+		if ($entity_subtype)
+			$where[] = "e.subtype=$entity_subtype";
+		if ($meta_name!="") {
+			if (!$meta_v) return false; // The value is set, but we didn't get a value... so something went wrong.
+			$where[] = "m.name_id='$meta_n'";
+		}
+		if ($meta_value!="") {
+			if (!$meta_v) return false; // The value is set, but we didn't get a value... so something went wrong.
+			$where[] = "m.value_id='$meta_v'";
+		}
+		if ($site_guid > 0)
+			$where[] = "e.site_guid = {$site_guid}";
+		
+		$query = "SELECT m.*, n.string as name, v.string as value from {$CONFIG->dbprefix}entities e JOIN {$CONFIG->dbprefix}metadata m on e.guid = m.entity_guid JOIN {$CONFIG->dbprefix}metastrings v on m.value_id = v.id JOIN {$CONFIG->dbprefix}metastrings n on m.name_id = n.id where";
+		foreach ($where as $w)
+			$query .= " $w and ";
+		$query .= get_access_sql_suffix("e"); // Add access controls
+		$query .= ' and ' . get_access_sql_suffix("m"); // Add access controls
+		$query .= " order by $order_by limit $offset, $limit"; // Add order and limit
+
+		return get_data($query, "row_to_elggmetadata");
+	}
+	
+	/**
+	 * Return a list of entities based on the given search criteria.
+	 * 
+	 * @param mixed $meta_name 
+	 * @param mixed $meta_value
+	 * @param string $entity_type The type of entity to look for, eg 'site' or 'object'
+	 * @param string $entity_subtype The subtype of the entity.
+	 * @param int $limit 
+	 * @param int $offset
+	 * @param string $order_by Optional ordering.
+	 * @param int $site_guid The site to get entities for. Leave as 0 (default) for the current site; -1 for all sites.
+	 * @param true|false $count If set to true, returns the total number of entities rather than a list. (Default: false)
+	 * 
+	 * @return int|array A list of entities, or a count if $count is set to true
+	 */
+	function get_entities_from_metadata($meta_name, $meta_value = "", $entity_type = "", $entity_subtype = "", $owner_guid = 0, $limit = 10, $offset = 0, $order_by = "", $site_guid = 0, $count = false)
+	{
+		global $CONFIG;
+		
+		$meta_n = get_metastring_id($meta_name);
+		$meta_v = get_metastring_id($meta_value);
+			
+		$entity_type = sanitise_string($entity_type);
+		$entity_subtype = get_subtype_id($entity_type, $entity_subtype);
+		$limit = (int)$limit;
+		$offset = (int)$offset;
+		if ($order_by == "") 
+			$order_by = "e.time_created desc";
+		else
+			$order_by = "e.time_created, {$order_by}";
+		$order_by = sanitise_string($order_by);
+		$site_guid = (int) $site_guid;
+		if ((is_array($owner_guid) && (count($owner_guid)))) {
+			foreach($owner_guid as $key => $guid) {
+				$owner_guid[$key] = (int) $guid;
+			}
+		} else {
+			$owner_guid = (int) $owner_guid;
+		}
+		if ($site_guid == 0)
+			$site_guid = $CONFIG->site_guid;
+			
+		//$access = get_access_list();
+			
+		$where = array();
+		
+		if ($entity_type!=="")
+			$where[] = "e.type='$entity_type'";
+		if ($entity_subtype)
+			$where[] = "e.subtype=$entity_subtype";
+		if ($meta_name!=="")
+			$where[] = "m.name_id='$meta_n'";
+		if ($meta_value!=="")
+			$where[] = "m.value_id='$meta_v'";
+		if ($site_guid > 0)
+			$where[] = "e.site_guid = {$site_guid}";
+		if (is_array($owner_guid)) {
+			$where[] = "e.container_guid in (".implode(",",$owner_guid).")";
+		} else if ($owner_guid > 0)
+			$where[] = "e.container_guid = {$owner_guid}";
+		
+		if (!$count) {
+			$query = "SELECT distinct e.* "; 
+		} else {
+			$query = "SELECT count(distinct e.guid) as total ";
+		}
+			
+		$query .= "from {$CONFIG->dbprefix}entities e JOIN {$CONFIG->dbprefix}metadata m on e.guid = m.entity_guid where";
+		foreach ($where as $w)
+			$query .= " $w and ";
+		$query .= get_access_sql_suffix("e"); // Add access controls
+		$query .= ' and ' . get_access_sql_suffix("m"); // Add access controls
+		
+		if (!$count) {
+			$query .= " order by $order_by limit $offset, $limit"; // Add order and limit
+			return get_data($query, "entity_row_to_elggstar");
+		} else {
+			if ($row = get_data_row($query))
+				return $row->total;
+		}
+		return false;
+	}
+	
+	/**
+	 * Return a list of entities suitable for display based on the given search criteria.
+	 * 
+	 * @see elgg_view_entity_list
+	 * 
+	 * @param mixed $meta_name Metadata name to search on
+	 * @param mixed $meta_value The value to match, optionally
+	 * @param string $entity_type The type of entity to look for, eg 'site' or 'object'
+	 * @param string $entity_subtype The subtype of the entity
+	 * @param int $limit Number of entities to display per page
+	 * @param true|false $fullview Whether or not to display the full view (default: true)
+	 * @param true|false $viewtypetoggle Whether or not to allow users to toggle to the gallery view. Default: true
+	 * @param true|false $pagination Display pagination? Default: true
+	 * 
+	 * @return string A list of entities suitable for display
+	 */
+	function list_entities_from_metadata($meta_name, $meta_value = "", $entity_type = "", $entity_subtype = "", $owner_guid = 0, $limit = 10, $fullview = true, $viewtypetoggle = true, $pagination = true) {
+		
+		$offset = (int) get_input('offset');
+		$limit = (int) $limit;
+		$count = get_entities_from_metadata($meta_name, $meta_value, $entity_type, $entity_subtype, $owner_guid, $limit, $offset, "", 0, true);
+		$entities = get_entities_from_metadata($meta_name, $meta_value, $entity_type, $entity_subtype, $owner_guid, $limit, $offset, "", 0, false);
+		
+		return elgg_view_entity_list($entities, $count, $offset, $limit, $fullview, $viewtypetoggle, $pagination);
+		
+	}
+
+	/**
+	 * Returns a list of entities based on the given search criteria.
+	 *
+	 * @param array $meta_array Array of 'name' => 'value' pairs
+	 * @param string $entity_type The type of entity to look for, eg 'site' or 'object'
+	 * @param string $entity_subtype The subtype of the entity.
+	 * @param int $limit 
+	 * @param int $offset
+	 * @param string $order_by Optional ordering.
+	 * @param int $site_guid The site to get entities for. Leave as 0 (default) for the current site; -1 for all sites.
+	 * @param true|false $count If set to true, returns the total number of entities rather than a list. (Default: false)
+	 * @param string $meta_array_operator Operator used for joining the metadata array together
+	 * @return int|array List of ElggEntities, or the total number if count is set to false
+	 */
+	function get_entities_from_metadata_multi($meta_array, $entity_type = "", $entity_subtype = "", $owner_guid = 0, $limit = 10, $offset = 0, $order_by = "", $site_guid = 0, $count = false, $meta_array_operator = 'and')
+	{
+		global $CONFIG;
+		
+		if (!is_array($meta_array) || sizeof($meta_array) == 0) {
+			return false;
+		}
+		
+		$where = array();
+		
+		$mindex = 1;
+		$join = "";
+		$metawhere = array();
+		$meta_array_operator = sanitise_string($meta_array_operator);
+		foreach($meta_array as $meta_name => $meta_value) {
+			$meta_n = get_metastring_id($meta_name);
+			$meta_v = get_metastring_id($meta_value);
+			$join .= " JOIN {$CONFIG->dbprefix}metadata m{$mindex} on e.guid = m{$mindex}.entity_guid "; 
+			/*if ($meta_name!=="")
+				$where[] = "m{$mindex}.name_id='$meta_n'";
+			if ($meta_value!=="")
+				$where[] = "m{$mindex}.value_id='$meta_v'";*/
+			$metawhere[] = "(m{$mindex}.name_id='$meta_n' AND m{$mindex}.value_id='$meta_v')";
+			$mindex++;
+		}
+		$where[] = "(".implode($meta_array_operator, $metawhere).")";
+			
+		$entity_type = sanitise_string($entity_type);
+		$entity_subtype = get_subtype_id($entity_type, $entity_subtype);
+		$limit = (int)$limit;
+		$offset = (int)$offset;
+		if ($order_by == "") $order_by = "e.time_created desc";
+		$order_by = sanitise_string($order_by);
+		if ((is_array($owner_guid) && (count($owner_guid)))) {
+			foreach($owner_guid as $key => $guid) {
+				$owner_guid[$key] = (int) $guid;
+			}
+		} else {
+			$owner_guid = (int) $owner_guid;
+		}
+		
+		$site_guid = (int) $site_guid;
+		if ($site_guid == 0)
+			$site_guid = $CONFIG->site_guid;
+			
+		//$access = get_access_list();
+		
+		if ($entity_type!="")
+			$where[] = "e.type = '{$entity_type}'";
+		if ($entity_subtype)
+			$where[] = "e.subtype = {$entity_subtype}";
+		if ($site_guid > 0)
+			$where[] = "e.site_guid = {$site_guid}";
+		if (is_array($owner_guid)) {
+			$where[] = "e.container_guid in (".implode(",",$owner_guid).")";
+		} else if ($owner_guid > 0)
+			$where[] = "e.container_guid = {$owner_guid}";
+		//if ($owner_guid > 0)
+		//	$where[] = "e.container_guid = {$owner_guid}";
+		
+		if ($count) {
+			$query = "SELECT count(distinct e.guid) as total ";
+		} else {
+			$query = "SELECT distinct e.* "; 
+		}
+			
+		$query .= " from {$CONFIG->dbprefix}entities e {$join} where";
+		foreach ($where as $w)
+			$query .= " $w and ";
+		$query .= get_access_sql_suffix("e"); // Add access controls
+	
+		$mindex = 1;
+		foreach($meta_array as $meta_name => $meta_value) {
+			$query .= ' and ' . get_access_sql_suffix("m{$mindex}"); // Add access controls
+			$mindex++;
+		}
+		
+		if (!$count) {
+			$query .= " order by $order_by limit $offset, $limit"; // Add order and limit
+			return get_data($query, "entity_row_to_elggstar");
+		} else {
+			if ($count = get_data_row($query)) {
+				return $count->total;
+			}
+		}
+		return false;
+	}
+	
+	/**
+	 * Returns a viewable list of entities based on the given search criteria.
+	 *
+	 * @see elgg_view_entity_list
+	 * 
+	 * @param array $meta_array Array of 'name' => 'value' pairs
+	 * @param string $entity_type The type of entity to look for, eg 'site' or 'object'
+	 * @param string $entity_subtype The subtype of the entity.
+	 * @param int $limit 
+	 * @param int $offset
+	 * @param string $order_by Optional ordering.
+	 * @param true|false $fullview Whether or not to display the full view (default: true)
+	 * @param true|false $viewtypetoggle Whether or not to allow users to toggle to the gallery view. Default: true
+	 * @param true|false $pagination Display pagination? Default: true
+	 * @return string List of ElggEntities suitable for display
+	 */
+	function list_entities_from_metadata_multi($meta_array, $entity_type = "", $entity_subtype = "", $owner_guid = 0, $limit = 10, $fullview = true, $viewtypetoggle = true, $pagination = true) {
+		
+		$offset = (int) get_input('offset');
+		$limit = (int) $limit;
+		$count = get_entities_from_metadata_multi($meta_array, $entity_type, $entity_subtype, $owner_guid, $limit, $offset, "", $site_guid, true);
+		$entities = get_entities_from_metadata_multi($meta_array, $entity_type, $entity_subtype, $owner_guid, $limit, $offset, "", $site_guid, false);
+	
+		return elgg_view_entity_list($entities, $count, $offset, $limit, $fullview, $viewtypetoggle, $pagination);
+		
+	}
+	
+	/**
+	 * Clear all the metadata for a given entity, assuming you have access to that metadata.
+	 * 
+	 * @param int $guid
+	 */
+	function clear_metadata($entity_guid)
+	{
+		global $CONFIG;
+		
+		$entity_guid = (int)$entity_guid;
+		if ($entity = get_entity($entity_guid)) {
+			if ($entity->canEdit())
+				return delete_data("DELETE from {$CONFIG->dbprefix}metadata where entity_guid={$entity_guid}");
+		}
+		return false;
+	}
+	
+	/**
+	 * Clear all annotations belonging to a given owner_guid
+	 *
+	 * @param int $owner_guid The owner
+	 */
+	function clear_metadata_by_owner($owner_guid)
+	{
+		global $CONFIG;
+		
+		$owner_guid = (int)$owner_guid;
+		
+		$metas = get_data("SELECT id from {$CONFIG->dbprefix}metadata WHERE owner_guid=$owner_guid");
+		$deleted = 0;
+		
+		foreach ($metas as $id)
+		{
+			if (delete_metadata($id->id)) // Is this the best way?
+				$deleted++;
+		}
+		
+		return $deleted;
+	}
+	
+	/**
+	 * Handler called by trigger_plugin_hook on the "export" event.
+	 */
+	function export_metadata_plugin_hook($hook, $entity_type, $returnvalue, $params)
+	{
+		// Sanity check values
+		if ((!is_array($params)) && (!isset($params['guid'])))
+			throw new InvalidParameterException(elgg_echo('InvalidParameterException:GUIDNotForExport'));
+			
+		if (!is_array($returnvalue))
+			throw new InvalidParameterException(elgg_echo('InvalidParameterException:NonArrayReturnValue'));
+		
+		$guid = (int)$params['guid'];
+		$name = $params['name'];	
+		
+		$result = get_metadata_for_entity($guid); 
+				
+		if ($result)
+		{
+			foreach ($result as $r)
+				$returnvalue[] = $r->export();
+		}
+		
+		return $returnvalue;
+	}
+	
+	/**
+	 * Takes in a comma-separated string and returns an array of tags which have been trimmed and set to lower case
+	 *
+	 * @param string $string Comma-separated tag string
+	 * @return array|false An array of strings, or false on failure
+	 */
+	function string_to_tag_array($string) {
+		
+		if (is_string($string)) {
+			$ar = explode(",",$string);
+			$ar = array_map('trim', $ar); // trim blank spaces
+			$ar = array_map('elgg_strtolower', $ar); // make lower case : [Marcus Povey 20090605 - Using mb wrapper function using UTF8 safe function where available]
+			$ar = array_filter($ar, 'is_not_null'); // Remove null values
+			return $ar;
+		}
+		return false;
+		
+	}
+	
+	/**
+	 * Takes a metadata array (which has all kinds of properties) and turns it into a simple array of strings 
+	 *
+	 * @param array $array Metadata array
+	 * @return array Array of strings
+	 */
+	function metadata_array_to_values($array) {
+		
+		$valuearray = array();
+		
+		if (is_array($array)) {
+			foreach($array as $element) {
+				$valuearray[] = $element->value;
+			}
+		}
+		
+		return $valuearray;
+		
+	}
+	
+	/**
+	 * Get the URL for this item of metadata, by default this links to the export handler in the current view.
+	 *
+	 * @param int $id
+	 */
+	function get_metadata_url($id)
+	{
+		$id = (int)$id;
+		
+		if ($extender = get_metadata($id)) {
+			return get_extender_url($extender);	
+		} 
+		return 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 $subtype The subtype; all subtypes by default
+	 */
+	function register_metadata_as_independent($type, $subtype = '*') {
+		global $CONFIG;
+		if (!isset($CONFIG->independents)) $CONFIG->independents = array();
+		$CONFIG->independents[$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 $subtype The entity subtype
+	 * @return true|false
+	 */
+	function is_metadata_independent($type, $subtype) {
+		global $CONFIG;
+		if (empty($CONFIG->independents)) return false;
+		if (!empty($CONFIG->independents[$type][$subtype])
+			|| !empty($CONFIG->independents[$type]['*'])) return true;
+		return false;
+	}
+	
+	/**
+	 * 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 $object The entity itself
+	 */
+	function metadata_update($event, $object_type, $object) {
+		if ($object instanceof ElggEntity) {
+			if (!is_metadata_independent($object->getType(), $object->getSubtype())) {
+				global $CONFIG;
+				$access_id = (int) $object->access_id;
+				$guid = (int) $object->getGUID();
+				update_data("update {$CONFIG->dbprefix}metadata set access_id = {$access_id} where entity_guid = {$guid}");
+			}
+		}	
+		return true;	
+	}
+	
+	/**
+	 * Register a metadata url handler.
+	 *
+	 * @param string $function_name The function.
+	 * @param string $extender_name The name, default 'all'.
+	 */
+	function register_metadata_url_handler($function_name, $extender_name = "all") {
+		return register_extender_url_handler($function_name, 'metadata', $extender_name);
+	}
+		
+	/** Register the hook */
+	register_plugin_hook("export", "all", "export_metadata_plugin_hook", 2);
+	/** Call a function whenever an entity is updated **/
+	register_elgg_event_handler('update','all','metadata_update');
+	
+?>