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+<?php
+/**
+ * Functions for Elgg's access system for entities, metadata, and annotations.
+ *
+ * Access is generally saved in the database as access_id. This corresponds to
+ * one of the ACCESS_* constants defined in {@link elgglib.php} or the ID of an
+ * access collection.
+ *
+ * @package Elgg.Core
+ * @subpackage Access
+ * @link http://docs.elgg.org/Access
+ */
+
+/**
+ * Return an ElggCache static variable cache for the access caches
+ *
+ * @staticvar ElggStaticVariableCache $access_cache
+ * @return \ElggStaticVariableCache
+ * @access private
+ */
+function _elgg_get_access_cache() {
+ /**
+ * A default filestore cache using the dataroot.
+ */
+ static $access_cache;
+
+ if (!$access_cache) {
+ $access_cache = new ElggStaticVariableCache('access');
+ }
+
+ return $access_cache;
+}
+
+/**
+ * Return a string of access_ids for $user_id appropriate for inserting into an SQL IN clause.
+ *
+ * @uses get_access_array
+ *
+ * @link http://docs.elgg.org/Access
+ * @see get_access_array()
+ *
+ * @param int $user_id User ID; defaults to currently logged in user
+ * @param int $site_id Site ID; defaults to current site
+ * @param bool $flush If set to true, will refresh the access list from the
+ * database rather than using this function's cache.
+ *
+ * @return string A list of access collections suitable for using in an SQL call
+ * @access private
+ */
+function get_access_list($user_id = 0, $site_id = 0, $flush = false) {
+ global $CONFIG, $init_finished;
+ $cache = _elgg_get_access_cache();
+
+ if ($flush) {
+ $cache->clear();
+ }
+
+ if ($user_id == 0) {
+ $user_id = elgg_get_logged_in_user_guid();
+ }
+
+ if (($site_id == 0) && (isset($CONFIG->site_id))) {
+ $site_id = $CONFIG->site_id;
+ }
+ $user_id = (int) $user_id;
+ $site_id = (int) $site_id;
+
+ $hash = $user_id . $site_id . 'get_access_list';
+
+ if ($cache[$hash]) {
+ return $cache[$hash];
+ }
+
+ $access_array = get_access_array($user_id, $site_id, $flush);
+ $access = "(" . implode(",", $access_array) . ")";
+
+ if ($init_finished) {
+ $cache[$hash] = $access;
+ }
+
+ return $access;
+}
+
+/**
+ * Returns an array of access IDs a user is permitted to see.
+ *
+ * Can be overridden with the 'access:collections:read', 'user' plugin hook.
+ *
+ * This returns a list of all the collection ids a user owns or belongs
+ * to plus public and logged in access levels. If the user is an admin, it includes
+ * the private access level.
+ *
+ * @internal this is only used in core for creating the SQL where clause when
+ * retrieving content from the database. The friends access level is handled by
+ * get_access_sql_suffix().
+ *
+ * @see get_write_access_array() for the access levels that a user can write to.
+ *
+ * @param int $user_id User ID; defaults to currently logged in user
+ * @param int $site_id Site ID; defaults to current site
+ * @param bool $flush If set to true, will refresh the access ids from the
+ * database rather than using this function's cache.
+ *
+ * @return array An array of access collections ids
+ */
+function get_access_array($user_id = 0, $site_id = 0, $flush = false) {
+ global $CONFIG, $init_finished;
+
+ $cache = _elgg_get_access_cache();
+
+ if ($flush) {
+ $cache->clear();
+ }
+
+ if ($user_id == 0) {
+ $user_id = elgg_get_logged_in_user_guid();
+ }
+
+ if (($site_id == 0) && (isset($CONFIG->site_guid))) {
+ $site_id = $CONFIG->site_guid;
+ }
+
+ $user_id = (int) $user_id;
+ $site_id = (int) $site_id;
+
+ $hash = $user_id . $site_id . 'get_access_array';
+
+ if ($cache[$hash]) {
+ $access_array = $cache[$hash];
+ } else {
+ $access_array = array(ACCESS_PUBLIC);
+
+ // The following can only return sensible data if the user is logged in.
+ if (elgg_is_logged_in()) {
+ $access_array[] = ACCESS_LOGGED_IN;
+
+ // Get ACL memberships
+ $query = "SELECT am.access_collection_id"
+ . " FROM {$CONFIG->dbprefix}access_collection_membership am"
+ . " LEFT JOIN {$CONFIG->dbprefix}access_collections ag ON ag.id = am.access_collection_id"
+ . " WHERE am.user_guid = $user_id AND (ag.site_guid = $site_id OR ag.site_guid = 0)";
+
+ $collections = get_data($query);
+ if ($collections) {
+ foreach ($collections as $collection) {
+ if (!empty($collection->access_collection_id)) {
+ $access_array[] = (int)$collection->access_collection_id;
+ }
+ }
+ }
+
+ // Get ACLs owned.
+ $query = "SELECT ag.id FROM {$CONFIG->dbprefix}access_collections ag ";
+ $query .= "WHERE ag.owner_guid = $user_id AND (ag.site_guid = $site_id OR ag.site_guid = 0)";
+
+ $collections = get_data($query);
+ if ($collections) {
+ foreach ($collections as $collection) {
+ if (!empty($collection->id)) {
+ $access_array[] = (int)$collection->id;
+ }
+ }
+ }
+
+ $ignore_access = elgg_check_access_overrides($user_id);
+
+ if ($ignore_access == true) {
+ $access_array[] = ACCESS_PRIVATE;
+ }
+ }
+
+ if ($init_finished) {
+ $cache[$hash] = $access_array;
+ }
+ }
+
+ $options = array(
+ 'user_id' => $user_id,
+ 'site_id' => $site_id
+ );
+
+ return elgg_trigger_plugin_hook('access:collections:read', 'user', $options, $access_array);
+}
+
+/**
+ * Gets the default access permission.
+ *
+ * This returns the default access level for the site or optionally for the user.
+ *
+ * @param ElggUser $user Get the user's default access. Defaults to logged in user.
+ *
+ * @return int default access id (see ACCESS defines in elgglib.php)
+ * @link http://docs.elgg.org/Access
+ */
+function get_default_access(ElggUser $user = null) {
+ global $CONFIG;
+
+ if (!$CONFIG->allow_user_default_access) {
+ return $CONFIG->default_access;
+ }
+
+ if (!($user) && (!$user = elgg_get_logged_in_user_entity())) {
+ return $CONFIG->default_access;
+ }
+
+ if (false !== ($default_access = $user->getPrivateSetting('elgg_default_access'))) {
+ return $default_access;
+ } else {
+ return $CONFIG->default_access;
+ }
+}
+
+/**
+ * Allow disabled entities and metadata to be returned by getter functions
+ *
+ * @todo Replace this with query object!
+ * @global bool $ENTITY_SHOW_HIDDEN_OVERRIDE
+ * @access private
+ */
+$ENTITY_SHOW_HIDDEN_OVERRIDE = false;
+
+/**
+ * Show or hide disabled entities.
+ *
+ * @param bool $show_hidden Show disabled entities.
+ * @return void
+ * @access private
+ */
+function access_show_hidden_entities($show_hidden) {
+ global $ENTITY_SHOW_HIDDEN_OVERRIDE;
+ $ENTITY_SHOW_HIDDEN_OVERRIDE = $show_hidden;
+}
+
+/**
+ * Return current status of showing disabled entities.
+ *
+ * @return bool
+ * @access private
+ */
+function access_get_show_hidden_status() {
+ global $ENTITY_SHOW_HIDDEN_OVERRIDE;
+ return $ENTITY_SHOW_HIDDEN_OVERRIDE;
+}
+
+/**
+ * Returns the SQL where clause for a table with a access_id and enabled columns.
+ *
+ * This handles returning where clauses for ACCESS_FRIENDS and the currently
+ * unused block and filter lists in addition to using get_access_list() for
+ * access collections and the standard access levels.
+ *
+ * @param string $table_prefix Optional table. prefix for the access code.
+ * @param int $owner The guid to check access for. Defaults to logged in user.
+ *
+ * @return string The SQL for a where clause
+ * @access private
+ */
+function get_access_sql_suffix($table_prefix = '', $owner = null) {
+ global $ENTITY_SHOW_HIDDEN_OVERRIDE, $CONFIG;
+
+ $sql = "";
+ $friends_bit = "";
+ $enemies_bit = "";
+
+ if ($table_prefix) {
+ $table_prefix = sanitise_string($table_prefix) . ".";
+ }
+
+ if (!isset($owner)) {
+ $owner = elgg_get_logged_in_user_guid();
+ }
+
+ if (!$owner) {
+ $owner = -1;
+ }
+
+ $ignore_access = elgg_check_access_overrides($owner);
+ $access = get_access_list($owner);
+
+ if ($ignore_access) {
+ $sql = " (1 = 1) ";
+ } else if ($owner != -1) {
+ // we have an entity's guid and auto check for friend relationships
+ $friends_bit = "{$table_prefix}access_id = " . ACCESS_FRIENDS . "
+ AND {$table_prefix}owner_guid IN (
+ SELECT guid_one FROM {$CONFIG->dbprefix}entity_relationships
+ WHERE relationship='friend' AND guid_two=$owner
+ )";
+
+ $friends_bit = '(' . $friends_bit . ') OR ';
+
+ // @todo untested and unsupported at present
+ if ((isset($CONFIG->user_block_and_filter_enabled)) && ($CONFIG->user_block_and_filter_enabled)) {
+ // check to see if the user is in the entity owner's block list
+ // or if the entity owner is in the user's filter list
+ // if so, disallow access
+ $enemies_bit = get_access_restriction_sql('elgg_block_list', "{$table_prefix}owner_guid", $owner, false);
+ $enemies_bit = '('
+ . $enemies_bit
+ . ' AND ' . get_access_restriction_sql('elgg_filter_list', $owner, "{$table_prefix}owner_guid", false)
+ . ')';
+ }
+ }
+
+ if (empty($sql)) {
+ $sql = " $friends_bit ({$table_prefix}access_id IN {$access}
+ OR ({$table_prefix}owner_guid = {$owner})
+ OR (
+ {$table_prefix}access_id = " . ACCESS_PRIVATE . "
+ AND {$table_prefix}owner_guid = $owner
+ )
+ )";
+ }
+
+ if ($enemies_bit) {
+ $sql = "$enemies_bit AND ($sql)";
+ }
+
+ if (!$ENTITY_SHOW_HIDDEN_OVERRIDE) {
+ $sql .= " and {$table_prefix}enabled='yes'";
+ }
+
+ return '(' . $sql . ')';
+}
+
+/**
+ * Get the where clause for an access restriction based on annotations
+ *
+ * Returns an SQL fragment that is true (or optionally false) if the given user has
+ * added an annotation with the given name to the given entity.
+ *
+ * @warning this is a private function for an untested capability and will likely
+ * be removed from a future version of Elgg.
+ *
+ * @param string $annotation_name Name of the annotation
+ * @param string $entity_guid SQL GUID of entity the annotation is attached to.
+ * @param string $owner_guid SQL string that evaluates to the GUID of the annotation owner
+ * @param boolean $exists If true, returns BOOL if the annotation exists
+ *
+ * @return string An SQL fragment suitable for inserting into a WHERE clause
+ * @access private
+ */
+function get_access_restriction_sql($annotation_name, $entity_guid, $owner_guid, $exists) {
+ global $CONFIG;
+
+ if ($exists) {
+ $not = '';
+ } else {
+ $not = 'NOT';
+ }
+
+ $sql = <<<END
+$not EXISTS (SELECT * FROM {$CONFIG->dbprefix}annotations a
+INNER JOIN {$CONFIG->dbprefix}metastrings ms ON (a.name_id = ms.id)
+WHERE ms.string = '$annotation_name'
+AND a.entity_guid = $entity_guid
+AND a.owner_guid = $owner_guid)
+END;
+ return $sql;
+}
+
+/**
+ * Can a user access an entity.
+ *
+ * @warning If a logged in user doesn't have access to an entity, the
+ * core engine will not load that entity.
+ *
+ * @tip This is mostly useful for checking if a user other than the logged in
+ * user has access to an entity that is currently loaded.
+ *
+ * @todo This function would be much more useful if we could pass the guid of the
+ * entity to test access for. We need to be able to tell whether the entity exists
+ * and whether the user has access to the entity.
+ *
+ * @param ElggEntity $entity The entity to check access for.
+ * @param ElggUser $user Optionally user to check access for. Defaults to
+ * logged in user (which is a useless default).
+ *
+ * @return bool
+ * @link http://docs.elgg.org/Access
+ */
+function has_access_to_entity($entity, $user = null) {
+ global $CONFIG;
+
+ if (!isset($user)) {
+ $access_bit = get_access_sql_suffix("e");
+ } else {
+ $access_bit = get_access_sql_suffix("e", $user->getGUID());
+ }
+
+ $query = "SELECT guid from {$CONFIG->dbprefix}entities e WHERE e.guid = " . $entity->getGUID();
+ // Add access controls
+ $query .= " AND " . $access_bit;
+ if (get_data($query)) {
+ return true;
+ } else {
+ return false;
+ }
+}
+
+/**
+ * Returns an array of access permissions that the user is allowed to save content with.
+ * Permissions returned are of the form (id => 'name').
+ *
+ * Example return value in English:
+ * array(
+ * 0 => 'Private',
+ * -2 => 'Friends',
+ * 1 => 'Logged in users',
+ * 2 => 'Public',
+ * 34 => 'My favorite friends',
+ * );
+ *
+ * Plugin hook of 'access:collections:write', 'user'
+ *
+ * @warning this only returns access collections that the user owns plus the
+ * standard access levels. It does not return access collections that the user
+ * belongs to such as the access collection for a group.
+ *
+ * @param int $user_id The user's GUID.
+ * @param int $site_id The current site.
+ * @param bool $flush If this is set to true, this will ignore a cached access array
+ *
+ * @return array List of access permissions
+ * @link http://docs.elgg.org/Access
+ */
+function get_write_access_array($user_id = 0, $site_id = 0, $flush = false) {
+ global $CONFIG, $init_finished;
+ $cache = _elgg_get_access_cache();
+
+ if ($flush) {
+ $cache->clear();
+ }
+
+ if ($user_id == 0) {
+ $user_id = elgg_get_logged_in_user_guid();
+ }
+
+ if (($site_id == 0) && (isset($CONFIG->site_id))) {
+ $site_id = $CONFIG->site_id;
+ }
+
+ $user_id = (int) $user_id;
+ $site_id = (int) $site_id;
+
+ $hash = $user_id . $site_id . 'get_write_access_array';
+
+ if ($cache[$hash]) {
+ $access_array = $cache[$hash];
+ } else {
+ // @todo is there such a thing as public write access?
+ $access_array = array(
+ ACCESS_PRIVATE => elgg_echo("PRIVATE"),
+ ACCESS_FRIENDS => elgg_echo("access:friends:label"),
+ ACCESS_LOGGED_IN => elgg_echo("LOGGED_IN"),
+ ACCESS_PUBLIC => elgg_echo("PUBLIC")
+ );
+
+ $query = "SELECT ag.* FROM {$CONFIG->dbprefix}access_collections ag ";
+ $query .= " WHERE (ag.site_guid = $site_id OR ag.site_guid = 0)";
+ $query .= " AND (ag.owner_guid = $user_id)";
+
+ $collections = get_data($query);
+ if ($collections) {
+ foreach ($collections as $collection) {
+ $access_array[$collection->id] = $collection->name;
+ }
+ }
+
+ if ($init_finished) {
+ $cache[$hash] = $access_array;
+ }
+ }
+
+ $options = array(
+ 'user_id' => $user_id,
+ 'site_id' => $site_id
+ );
+ return elgg_trigger_plugin_hook('access:collections:write', 'user',
+ $options, $access_array);
+}
+
+/**
+ * Can the user change this access collection?
+ *
+ * Use the plugin hook of 'access:collections:write', 'user' to change this.
+ * @see get_write_access_array() for details on the hook.
+ *
+ * Respects access control disabling for admin users and {@see elgg_set_ignore_access()}
+ *
+ * @see get_write_access_array()
+ *
+ * @param int $collection_id The collection id
+ * @param mixed $user_guid The user GUID to check for. Defaults to logged in user.
+ * @return bool
+ */
+function can_edit_access_collection($collection_id, $user_guid = null) {
+ if ($user_guid) {
+ $user = get_entity((int) $user_guid);
+ } else {
+ $user = elgg_get_logged_in_user_entity();
+ }
+
+ $collection = get_access_collection($collection_id);
+
+ if (!($user instanceof ElggUser) || !$collection) {
+ return false;
+ }
+
+ $write_access = get_write_access_array($user->getGUID(), 0, true);
+
+ // don't ignore access when checking users.
+ if ($user_guid) {
+ return array_key_exists($collection_id, $write_access);
+ } else {
+ return elgg_get_ignore_access() || array_key_exists($collection_id, $write_access);
+ }
+}
+
+/**
+ * Creates a new access collection.
+ *
+ * Access colletions allow plugins and users to create granular access
+ * for entities.
+ *
+ * Triggers plugin hook 'access:collections:addcollection', 'collection'
+ *
+ * @internal Access collections are stored in the access_collections table.
+ * Memberships to collections are in access_collections_membership.
+ *
+ * @param string $name The name of the collection.
+ * @param int $owner_guid The GUID of the owner (default: currently logged in user).
+ * @param int $site_guid The GUID of the site (default: current site).
+ *
+ * @return int|false The collection ID if successful and false on failure.
+ * @link http://docs.elgg.org/Access/Collections
+ * @see update_access_collection()
+ * @see delete_access_collection()
+ */
+function create_access_collection($name, $owner_guid = 0, $site_guid = 0) {
+ global $CONFIG;
+
+ $name = trim($name);
+ if (empty($name)) {
+ return false;
+ }
+
+ if ($owner_guid == 0) {
+ $owner_guid = elgg_get_logged_in_user_guid();
+ }
+ if (($site_guid == 0) && (isset($CONFIG->site_guid))) {
+ $site_guid = $CONFIG->site_guid;
+ }
+ $name = sanitise_string($name);
+
+ $q = "INSERT INTO {$CONFIG->dbprefix}access_collections
+ SET name = '{$name}',
+ owner_guid = {$owner_guid},
+ site_guid = {$site_guid}";
+ $id = insert_data($q);
+ if (!$id) {
+ return false;
+ }
+
+ $params = array(
+ 'collection_id' => $id
+ );
+
+ if (!elgg_trigger_plugin_hook('access:collections:addcollection', 'collection', $params, true)) {
+ return false;
+ }
+
+ return $id;
+}
+
+/**
+ * Updates the membership in an access collection.
+ *
+ * @warning Expects a full list of all members that should
+ * be part of the access collection
+ *
+ * @note This will run all hooks associated with adding or removing
+ * members to access collections.
+ *
+ * @param int $collection_id The ID of the collection.
+ * @param array $members Array of member GUIDs
+ *
+ * @return bool
+ * @link http://docs.elgg.org/Access/Collections
+ * @see add_user_to_access_collection()
+ * @see remove_user_from_access_collection()
+ */
+function update_access_collection($collection_id, $members) {
+ $acl = get_access_collection($collection_id);
+
+ if (!$acl) {
+ return false;
+ }
+ $members = (is_array($members)) ? $members : array();
+
+ $cur_members = get_members_of_access_collection($collection_id, true);
+ $cur_members = (is_array($cur_members)) ? $cur_members : array();
+
+ $remove_members = array_diff($cur_members, $members);
+ $add_members = array_diff($members, $cur_members);
+
+ $result = true;
+
+ foreach ($add_members as $guid) {
+ $result = $result && add_user_to_access_collection($guid, $collection_id);
+ }
+
+ foreach ($remove_members as $guid) {
+ $result = $result && remove_user_from_access_collection($guid, $collection_id);
+ }
+
+ return $result;
+}
+
+/**
+ * Deletes a specified access collection and its membership.
+ *
+ * @param int $collection_id The collection ID
+ *
+ * @return bool
+ * @link http://docs.elgg.org/Access/Collections
+ * @see create_access_collection()
+ * @see update_access_collection()
+ */
+function delete_access_collection($collection_id) {
+ global $CONFIG;
+
+ $collection_id = (int) $collection_id;
+ $params = array('collection_id' => $collection_id);
+
+ if (!elgg_trigger_plugin_hook('access:collections:deletecollection', 'collection', $params, true)) {
+ return false;
+ }
+
+ // Deleting membership doesn't affect result of deleting ACL.
+ $q = "DELETE FROM {$CONFIG->dbprefix}access_collection_membership
+ WHERE access_collection_id = {$collection_id}";
+ delete_data($q);
+
+ $q = "DELETE FROM {$CONFIG->dbprefix}access_collections
+ WHERE id = {$collection_id}";
+ $result = delete_data($q);
+
+ return (bool)$result;
+}
+
+/**
+ * Get a specified access collection
+ *
+ * @note This doesn't return the members of an access collection,
+ * just the database row of the actual collection.
+ *
+ * @see get_members_of_access_collection()
+ *
+ * @param int $collection_id The collection ID
+ *
+ * @return object|false
+ */
+function get_access_collection($collection_id) {
+ global $CONFIG;
+ $collection_id = (int) $collection_id;
+
+ $query = "SELECT * FROM {$CONFIG->dbprefix}access_collections WHERE id = {$collection_id}";
+ $get_collection = get_data_row($query);
+
+ return $get_collection;
+}
+
+/**
+ * Adds a user to an access collection.
+ *
+ * Triggers the 'access:collections:add_user', 'collection' plugin hook.
+ *
+ * @param int $user_guid The GUID of the user to add
+ * @param int $collection_id The ID of the collection to add them to
+ *
+ * @return bool
+ * @see update_access_collection()
+ * @see remove_user_from_access_collection()
+ * @link http://docs.elgg.org/Access/Collections
+ */
+function add_user_to_access_collection($user_guid, $collection_id) {
+ global $CONFIG;
+
+ $collection_id = (int) $collection_id;
+ $user_guid = (int) $user_guid;
+ $user = get_user($user_guid);
+
+ $collection = get_access_collection($collection_id);
+
+ if (!($user instanceof Elgguser) || !$collection) {
+ return false;
+ }
+
+ $params = array(
+ 'collection_id' => $collection_id,
+ 'user_guid' => $user_guid
+ );
+
+ $result = elgg_trigger_plugin_hook('access:collections:add_user', 'collection', $params, true);
+ if ($result == false) {
+ return false;
+ }
+
+ // if someone tries to insert the same data twice, we do a no-op on duplicate key
+ $q = "INSERT INTO {$CONFIG->dbprefix}access_collection_membership
+ SET access_collection_id = $collection_id, user_guid = $user_guid
+ ON DUPLICATE KEY UPDATE user_guid = user_guid";
+ $result = insert_data($q);
+
+ return $result !== false;
+}
+
+/**
+ * Removes a user from an access collection.
+ *
+ * Triggers the 'access:collections:remove_user', 'collection' plugin hook.
+ *
+ * @param int $user_guid The user GUID
+ * @param int $collection_id The access collection ID
+ *
+ * @return bool
+ * @see update_access_collection()
+ * @see remove_user_from_access_collection()
+ * @link http://docs.elgg.org/Access/Collections
+ */
+function remove_user_from_access_collection($user_guid, $collection_id) {
+ global $CONFIG;
+
+ $collection_id = (int) $collection_id;
+ $user_guid = (int) $user_guid;
+ $user = get_user($user_guid);
+
+ $collection = get_access_collection($collection_id);
+
+ if (!($user instanceof Elgguser) || !$collection) {
+ return false;
+ }
+
+ $params = array(
+ 'collection_id' => $collection_id,
+ 'user_guid' => $user_guid
+ );
+
+ if (!elgg_trigger_plugin_hook('access:collections:remove_user', 'collection', $params, true)) {
+ return false;
+ }
+
+ $q = "DELETE FROM {$CONFIG->dbprefix}access_collection_membership
+ WHERE access_collection_id = {$collection_id}
+ AND user_guid = {$user_guid}";
+
+ return (bool)delete_data($q);
+}
+
+/**
+ * Returns an array of database row objects of the access collections owned by $owner_guid.
+ *
+ * @param int $owner_guid The entity guid
+ * @param int $site_guid The GUID of the site (default: current site).
+ *
+ * @return array|false
+ * @see add_access_collection()
+ * @see get_members_of_access_collection()
+ * @link http://docs.elgg.org/Access/Collections
+ */
+function get_user_access_collections($owner_guid, $site_guid = 0) {
+ global $CONFIG;
+ $owner_guid = (int) $owner_guid;
+ $site_guid = (int) $site_guid;
+
+ if (($site_guid == 0) && (isset($CONFIG->site_guid))) {
+ $site_guid = $CONFIG->site_guid;
+ }
+
+ $query = "SELECT * FROM {$CONFIG->dbprefix}access_collections
+ WHERE owner_guid = {$owner_guid}
+ AND site_guid = {$site_guid}";
+
+ $collections = get_data($query);
+
+ return $collections;
+}
+
+/**
+ * Get all of members of an access collection
+ *
+ * @param int $collection The collection's ID
+ * @param bool $idonly If set to true, will only return the members' GUIDs (default: false)
+ *
+ * @return array ElggUser guids or entities if successful, false if not
+ * @see add_user_to_access_collection()
+ * @see http://docs.elgg.org/Access/Collections
+ */
+function get_members_of_access_collection($collection, $idonly = FALSE) {
+ global $CONFIG;
+ $collection = (int)$collection;
+
+ if (!$idonly) {
+ $query = "SELECT e.* FROM {$CONFIG->dbprefix}access_collection_membership m"
+ . " JOIN {$CONFIG->dbprefix}entities e ON e.guid = m.user_guid"
+ . " WHERE m.access_collection_id = {$collection}";
+ $collection_members = get_data($query, "entity_row_to_elggstar");
+ } else {
+ $query = "SELECT e.guid FROM {$CONFIG->dbprefix}access_collection_membership m"
+ . " JOIN {$CONFIG->dbprefix}entities e ON e.guid = m.user_guid"
+ . " WHERE m.access_collection_id = {$collection}";
+ $collection_members = get_data($query);
+ if (!$collection_members) {
+ return FALSE;
+ }
+ foreach ($collection_members as $key => $val) {
+ $collection_members[$key] = $val->guid;
+ }
+ }
+
+ return $collection_members;
+}
+
+/**
+ * Return entities based upon access id.
+ *
+ * @param array $options Any options accepted by {@link elgg_get_entities()} and
+ * access_id => int The access ID of the entity.
+ *
+ * @see elgg_get_entities()
+ * @return mixed If count, int. If not count, array. false on errors.
+ * @since 1.7.0
+ */
+function elgg_get_entities_from_access_id(array $options = array()) {
+ // restrict the resultset to access collection provided
+ if (!isset($options['access_id'])) {
+ return FALSE;
+ }
+
+ // @todo add support for an array of collection_ids
+ $where = "e.access_id = '{$options['access_id']}'";
+ if (isset($options['wheres'])) {
+ if (is_array($options['wheres'])) {
+ $options['wheres'][] = $where;
+ } else {
+ $options['wheres'] = array($options['wheres'], $where);
+ }
+ } else {
+ $options['wheres'] = array($where);
+ }
+
+ // return entities with the desired options
+ return elgg_get_entities($options);
+}
+
+/**
+ * Lists entities from an access collection
+ *
+ * @param array $options See elgg_list_entities() and elgg_get_entities_from_access_id()
+ *
+ * @see elgg_list_entities()
+ * @see elgg_get_entities_from_access_id()
+ *
+ * @return string
+ */
+function elgg_list_entities_from_access_id(array $options = array()) {
+ return elgg_list_entities($options, 'elgg_get_entities_from_access_id');
+}
+
+/**
+ * Return the name of an ACCESS_* constant or a access collection,
+ * but only if the user has write access on that ACL.
+ *
+ * @warning This function probably doesn't work how it's meant to.
+ *
+ * @param int $entity_access_id The entity's access id
+ *
+ * @return string 'Public', 'Private', etc.
+ * @since 1.7.0
+ * @todo I think this probably wants get_access_array() instead of get_write_access_array(),
+ * but those two functions return different types of arrays.
+ */
+function get_readable_access_level($entity_access_id) {
+ $access = (int) $entity_access_id;
+
+ //get the access level for object in readable string
+ $options = get_write_access_array();
+
+ if (array_key_exists($access, $options)) {
+ return $options[$access];
+ }
+
+ // return 'Limited' if the user does not have access to the access collection
+ return elgg_echo('access:limited:label');
+}
+
+/**
+ * Set if entity access system should be ignored.
+ *
+ * The access system will not return entities in any getter
+ * functions if the user doesn't have access.
+ *
+ * @internal For performance reasons this is done at the database access clause level.
+ *
+ * @tip Use this to access entities in automated scripts
+ * when no user is logged in.
+ *
+ * @note This clears the access cache.
+ *
+ * @warning This will not show disabled entities.
+ * Use {@link access_show_hidden_entities()} to access disabled entities.
+ *
+ * @param bool $ignore If true, disables all access checks.
+ *
+ * @return bool Previous ignore_access setting.
+ * @since 1.7.0
+ * @see http://docs.elgg.org/Access/IgnoreAccess
+ * @see elgg_get_ignore_access()
+ */
+function elgg_set_ignore_access($ignore = true) {
+ $cache = _elgg_get_access_cache();
+ $cache->clear();
+ $elgg_access = elgg_get_access_object();
+ return $elgg_access->setIgnoreAccess($ignore);
+}
+
+/**
+ * Get current ignore access setting.
+ *
+ * @return bool
+ * @since 1.7.0
+ * @see http://docs.elgg.org/Access/IgnoreAccess
+ * @see elgg_set_ignore_access()
+ */
+function elgg_get_ignore_access() {
+ return elgg_get_access_object()->getIgnoreAccess();
+}
+
+/**
+ * Decides if the access system should be ignored for a user.
+ *
+ * Returns true (meaning ignore access) if either of these 2 conditions are true:
+ * 1) an admin user guid is passed to this function.
+ * 2) {@link elgg_get_ignore_access()} returns true.
+ *
+ * @see elgg_set_ignore_access()
+ *
+ * @param int $user_guid The user to check against.
+ *
+ * @return bool
+ * @since 1.7.0
+ */
+function elgg_check_access_overrides($user_guid = 0) {
+ if (!$user_guid || $user_guid <= 0) {
+ $is_admin = false;
+ } else {
+ $is_admin = elgg_is_admin_user($user_guid);
+ }
+
+ return ($is_admin || elgg_get_ignore_access());
+}
+
+/**
+ * Returns the ElggAccess object.
+ *
+ * // @todo comment is incomplete
+ * This is used to
+ *
+ * @return ElggAccess
+ * @since 1.7.0
+ * @access private
+ */
+function elgg_get_access_object() {
+ static $elgg_access;
+
+ if (!$elgg_access) {
+ $elgg_access = new ElggAccess();
+ }
+
+ return $elgg_access;
+}
+
+/**
+ * A flag to set if Elgg's access initialization is finished.
+ *
+ * @global bool $init_finished
+ * @access private
+ * @todo This is required to tell the access system to start caching because
+ * calls are made while in ignore access mode and before the user is logged in.
+ */
+$init_finished = false;
+
+/**
+ * A quick and dirty way to make sure the access permissions have been correctly set up
+ *
+ * @elgg_event_handler init system
+ * @todo Invesigate
+ *
+ * @return void
+ */
+function access_init() {
+ global $init_finished;
+ $init_finished = true;
+}
+
+/**
+ * Overrides the access system if appropriate.
+ *
+ * Allows admin users and calls after {@link elgg_set_ignore_access} to
+ * bypass the access system.
+ *
+ * Registered for the 'permissions_check', 'all' and the
+ * 'container_permissions_check', 'all' plugin hooks.
+ *
+ * Returns true to override the access system or null if no change is needed.
+ *
+ * @param string $hook
+ * @param string $type
+ * @param bool $value
+ * @param array $params
+ * @return true|null
+ * @access private
+ */
+function elgg_override_permissions($hook, $type, $value, $params) {
+ $user = elgg_extract('user', $params);
+ if ($user) {
+ $user_guid = $user->getGUID();
+ } else {
+ $user_guid = elgg_get_logged_in_user_guid();
+ }
+
+ // don't do this so ignore access still works with no one logged in
+ //if (!$user instanceof ElggUser) {
+ // return false;
+ //}
+
+ // check for admin
+ if ($user_guid && elgg_is_admin_user($user_guid)) {
+ return true;
+ }
+
+ // check access overrides
+ if ((elgg_check_access_overrides($user_guid))) {
+ return true;
+ }
+
+ // consult other hooks
+ return NULL;
+}
+
+/**
+ * Runs unit tests for the entities object.
+ *
+ * @param string $hook
+ * @param string $type
+ * @param array $value
+ * @param array $params
+ * @return array
+ *
+ * @access private
+ */
+function access_test($hook, $type, $value, $params) {
+ global $CONFIG;
+
+ $value[] = $CONFIG->path . 'engine/tests/api/access_collections.php';
+ return $value;
+}
+
+// Tell the access functions the system has booted, plugins are loaded,
+// and the user is logged in so it can start caching
+elgg_register_event_handler('ready', 'system', 'access_init');
+
+// For overrided permissions
+elgg_register_plugin_hook_handler('permissions_check', 'all', 'elgg_override_permissions');
+elgg_register_plugin_hook_handler('container_permissions_check', 'all', 'elgg_override_permissions');
+
+elgg_register_plugin_hook_handler('unit_test', 'system', 'access_test'); \ No newline at end of file