<?php /** * Elgg relationships. * Stub containing relationship functions, making import and export easier. * * @package Elgg * @subpackage Core * @license http://www.gnu.org/licenses/old-licenses/gpl-2.0.html GNU Public License version 2 * @author Marcus Povey <marcus@dushka.co.uk> * @copyright Curverider Ltd 2008 * @link http://elgg.org/ */ /** * Relationship class. * * @author Marcus Povey * @package Elgg * @subpackage Core */ class ElggRelationship implements Importable, Exportable, Iterator, // Override foreach behaviour ArrayAccess // Override for array access { /** * This contains the site's main properties (id, etc) * @var array */ protected $attributes; /** * 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) $relationship = $id; // Create from db row else $relationship = get_relationship($id); if ($relationship) { $objarray = (array) $relationship; foreach($objarray as $key => $value) { $this->attributes[$key] = $value; } } } } /** * Class member get overloading * * @param string $name * @return mixed */ protected function __get($name) { if (isset($this->attributes[$name])) return $this->attributes[$name]; return null; } /** * Class member set overloading * * @param string $name * @param mixed $value * @return mixed */ protected function __set($name, $value) { $this->attributes[$name] = $value; return true; } /** * Save the relationship * * @return int the relationship id */ public function save() { if ($this->id > 0) { delete_relationship($this->id); } $this->id = add_entity_relationship($this->guid_one, $this->relationship, $this->guid_two); if (!$this->id) throw new IOException("Unable to save new ElggAnnotation"); return $this->id; } /** * Delete a given relationship. */ public function delete() { return delete_relationship($this->id); } // EXPORTABLE INTERFACE //////////////////////////////////////////////////////////// /** * Export this relationship * * @return array */ public function export() { return new ODDRelationship( guid_to_uuid($this->guid_one), $this->relationship, guid_to_uuid($this->guid_two) ); } // IMPORTABLE INTERFACE //////////////////////////////////////////////////////////// /** * Import a relationship * * @param array $data * @param int $version * @return ElggRelationship * @throws ImportException */ public function import(ODD $data) { if (!($element instanceof ODDRelationship)) throw new InvalidParameterException("ElggRelationship::import() passed an unexpected ODD class"); $uuid_one = $data->getAttribute('uuid1'); $uuid_two = $data->getAttribute('uuid2'); // See if this entity has already been imported, if so then we need to link to it $entity1 = get_entity_from_uuid($uuid_one); $entity2 = get_entity_from_uuid($uuid_two); if (($entity1) && ($entity2)) { // Set the item ID $this->attributes['guid_one'] = $entity1->getGUID(); $this->attributes['guid_two'] = $entity2->getGUID(); // Map verb to relationship //$verb = $data->getAttribute('verb'); //$relationship = get_relationship_from_verb($verb); $relationship = $data->getAttribute('type'); if ($relationship) { $this->attributes['relationship'] = $relationship; // save $result = $this->save(); if (!$result) throw new ImportException("There was a problem saving the ElggExtender"); return $this; } } } // ITERATOR INTERFACE ////////////////////////////////////////////////////////////// /* * This lets an entity's attributes be displayed using foreach as a normal array. * Example: http://www.sitepoint.com/print/php5-standard-library */ private $valid = FALSE; function rewind() { $this->valid = (FALSE !== reset($this->attributes)); } function current() { return current($this->attributes); } function key() { return key($this->attributes); } function next() { $this->valid = (FALSE !== next($this->attributes)); } function valid() { return $this->valid; } // ARRAY ACCESS INTERFACE ////////////////////////////////////////////////////////// /* * This lets an entity's attributes be accessed like an associative array. * Example: http://www.sitepoint.com/print/php5-standard-library */ function offsetSet($key, $value) { if ( array_key_exists($key, $this->attributes) ) { $this->attributes[$key] = $value; } } function offsetGet($key) { if ( array_key_exists($key, $this->attributes) ) { return $this->attributes[$key]; } } function offsetUnset($key) { if ( array_key_exists($key, $this->attributes) ) { $this->attributes[$key] = ""; // Full unsetting is dangerious for our objects } } function offsetExists($offset) { return array_key_exists($offset, $this->attributes); } } /** * Convert a database row to a new ElggRelationship * * @param stdClass $row * @return stdClass or ElggMetadata */ function row_to_elggrelationship($row) { if (!($row instanceof stdClass)) return $row; return new ElggRelationship($row); } /** * Return a relationship. * * @param int $id */ function get_relationship($id) { global $CONFIG; $id = (int)$id; return row_to_elggrelationship(get_data_row("SELECT * from {$CONFIG->dbprefix}entity_relationships where id=$id")); } /** * Delete a specific relationship. * * @param int $id */ function delete_relationship($id) { global $CONFIG; $id = (int)$id; return row_to_elggrelationship(get_data_row("delete from {$CONFIG->dbprefix}entity_relationships where id=$id")); } /** * Define an arbitrary relationship between two entities. * This relationship could be a friendship, a group membership or a site membership. * * This function lets you make the statement "$guid_one has $relationship with $guid_two". * * TODO: Access controls? Are they necessary - I don't think so since we are defining * relationships between and anyone can do that. The objects should patch some access * controls over the top tho. * * @param int $guid_one * @param string $relationship * @param int $guid_two */ function add_entity_relationship($guid_one, $relationship, $guid_two) { global $CONFIG; $guid_one = (int)$guid_one; $relationship = sanitise_string($relationship); $guid_two = (int)$guid_two; return insert_data("INSERT into {$CONFIG->dbprefix}entity_relationships (guid_one, relationship, guid_two) values ($guid_one, '$relationship', $guid_two)"); } /** * Determine whether or not a relationship between two entities exists * * @param int $guid_one The GUID of the entity "owning" the relationship * @param string $relationship The type of relationship * @param int $guid_two The GUID of the entity the relationship is with * @return true|false */ function check_entity_relationship($guid_one, $relationship, $guid_two) { global $CONFIG; $guid_one = (int)$guid_one; $relationship = sanitise_string($relationship); $guid_two = (int)$guid_two; if ($row = get_data_row("select guid_one from {$CONFIG->dbprefix}entity_relationships where guid_one=$guid_one and relationship='$relationship' and guid_two=$guid_two limit 1")) { return true; } return false; } /** * Remove an arbitrary relationship between two entities. * * @param int $guid_one * @param string $relationship * @param int $guid_two */ function remove_entity_relationship($guid_one, $relationship, $guid_two) { global $CONFIG; $guid_one = (int)$guid_one; $relationship = sanitise_string($relationship); $guid_two = (int)$guid_two; return delete_data("DELETE from {$CONFIG->dbprefix}entity_relationships where guid_one=$guid_one and relationship='$relationship' and guid_two=$guid_two"); } /** * Removes all arbitrary relationships originating from a particular entity * * @param int $guid_one The GUID of the entity * @param string $relationship The name of the relationship (optionally) * @param true|false $inverse Whether we're deleting inverse relationships (default false) * @return true|false Depending on success */ function remove_entity_relationships($guid_one, $relationship = "", $inverse = false) { global $CONFIG; $guid_one = (int) $guid_one; if (!empty($relationship)) { $relationship = sanitise_string($relationship); $where = "and relationship='$relationship'"; } else { $where = ""; } if (!$inverse) { return delete_data("DELETE from {$CONFIG->dbprefix}entity_relationships where guid_one=$guid_one {$where}"); } else { return delete_data("DELETE from {$CONFIG->dbprefix}entity_relationships where guid_two=$guid_one {$where}"); } } /** * Get all the relationships for a given guid. * * @param int $guid */ function get_entity_relationships($guid) { global $CONFIG; $guid = (int)$guid; $query = "SELECT * from {$CONFIG->dbprefix}entity_relationships where guid_one=$guid"; return get_data($query, "row_to_elggrelationship"); } /** * Return entities matching a given query joining against a relationship. * * @param string $relationship The relationship eg "friends_of" * @param int $relationship_guid The guid of the entity to use query * @param bool $inverse_relationship Reverse the normal function of the query to instead say "give me all entities for whome $relationship_guid is a $relationship of" * @param string $type * @param string $subtype * @param int $owner_guid * @param string $order_by * @param int $limit * @param int $offset * @param boolean $count Set to true if you want to count the number of entities instead (default false) * @param int $site_guid The site to get entities for. Leave as 0 (default) for the current site; -1 for all sites. * @return array|int|false An array of entities, or the number of entities, or false on failure */ function get_entities_from_relationship($relationship, $relationship_guid, $inverse_relationship = false, $type = "", $subtype = "", $owner_guid = 0, $order_by = "time_created desc", $limit = 10, $offset = 0, $count = false, $site_guid = 0) { global $CONFIG; $relationship = sanitise_string($relationship); $relationship_guid = (int)$relationship_guid; $inverse_relationship = (bool)$inverse_relationship; $type = sanitise_string($type); $subtype = get_subtype_id($type, $subtype); $owner_guid = (int)$owner_guid; $order_by = sanitise_string($order_by); $limit = (int)$limit; $offset = (int)$offset; $site_guid = (int) $site_guid; if ($site_guid == 0) $site_guid = $CONFIG->site_guid; $access = get_access_list(); $where = array(); if ($relationship!="") $where[] = "r.relationship='$relationship'"; if ($relationship_guid) $where[] = ($inverse_relationship ? "r.guid_two='$relationship_guid'" : "r.guid_one='$relationship_guid'"); if ($type != "") $where[] = "e.type='$type'"; if ($subtype) $where[] = "e.subtype=$subtype"; if ($owner_guid != "") $where[] = "e.owner_guid='$owner_guid'"; if ($site_guid > 0) $where[] = "e.site_guid = {$site_guid}"; // Select what we're joining based on the options $joinon = "e.guid = r.guid_one"; if (!$inverse_relationship) $joinon = "e.guid = r.guid_two"; if ($count) { $query = "select count(distinct e.guid) as total "; } else { $query = "select distinct e.* "; } $query .= " from {$CONFIG->dbprefix}entity_relationships r JOIN {$CONFIG->dbprefix}entities e on $joinon where "; foreach ($where as $w) $query .= " $w and "; $query .= " (e.access_id in {$access} or (e.access_id = 0 and e.owner_guid = {$_SESSION['id']}))"; // Add access controls if (!$count) { $query .= " order by $order_by limit $offset, $limit"; // Add order and limit return get_data($query, "entity_row_to_elggstar"); } else { if ($count = get_data_row($query)) { return $count->total; } } return false; } /** * Handler called by trigger_plugin_hook on the "import" event. */ function import_relationship_plugin_hook($hook, $entity_type, $returnvalue, $params) { $element = $params['element']; $tmp = NULL; if ($element instanceof ODDRelationship) { $tmp = new ElggRelationship(); $tmp->import($element); return $tmp; } } /** * Handler called by trigger_plugin_hook on the "export" event. */ function export_relationship_plugin_hook($hook, $entity_type, $returnvalue, $params) { global $CONFIG; // Sanity check values if ((!is_array($params)) && (!isset($params['guid']))) throw new InvalidParameterException("GUID has not been specified during export, this should never happen."); if (!is_array($returnvalue)) throw new InvalidParameterException("Entity serialisation function passed a non-array returnvalue parameter"); $guid = (int)$params['guid']; $result = get_entity_relationships($guid); if ($result) { foreach ($result as $r) $returnvalue[] = $r->export(); } return $returnvalue; } /** Register the import hook */ register_plugin_hook("import", "all", "import_relationship_plugin_hook", 3); /** Register the hook, ensuring entities are serialised first */ register_plugin_hook("export", "all", "export_relationship_plugin_hook", 3); ?>