function friend_collections_message_picker_callback($query, $options = array())
{
    $id = sanitize_int(get_input('id'));
    $guids = get_members_of_access_collection($id, true);
    // replace mysql vars with escaped strings
    $q = str_replace(array('_', '%'), array('\\_', '\\%'), $query);
    if (!$guids || !$id) {
        return array();
    }
    $dbprefix = elgg_get_config('dbprefix');
    return elgg_get_entities(array('type' => 'user', 'joins' => array("JOIN {$dbprefix}users_entity ue ON ue.guid = e.guid", "JOIN {$dbprefix}access_collection_membership acm ON acm.user_guid = e.guid"), 'wheres' => array("ue.username LIKE '%{$q}%' OR ue.name LIKE '%{$q}%'", "acm.access_collection_id = {$id}"), 'order_by' => 'ue.name ASC'));
}

/**
 * Send push notifications if event is added to the activity river
 * 
 * @param string        $event      name of the event
 * @param string        $type       type of the event
 * @param ElggRiverItem $river_item river item object
 * 
 * @return void
 */
function ws_pack_created_river_event_handler($event, $type, $river_item)
{
    if (!empty($river_item) && $river_item instanceof ElggRiverItem) {
        if (!function_exists('str_get_html')) {
            elgg_load_library("simple_html_dom");
        }
        $message = "";
        $html_view = elgg_view_river_item($river_item);
        if ($res = str_get_html($html_view)) {
            // get the river summary
            if ($summary_element = $res->find("div.elgg-river-summary")) {
                $summary_element = $summary_element[0];
                $text = $summary_element->innertext();
                list($left, $right) = explode("<span class=\"elgg-river-timestamp\">", $text);
                $message = trim(elgg_strip_tags($left));
            }
        }
        if (!empty($message)) {
            $user_guids = false;
            switch ($river_item->access_id) {
                case ACCESS_PRIVATE:
                    // do nothing
                    break;
                case ACCESS_PUBLIC:
                case ACCESS_LOGGED_IN:
                    // notify everyone
                    $site_user_options = array("type" => "user", "limit" => false, "relationship" => "member_of_site", "relationship_guid" => elgg_get_site_entity()->getGUID(), "inverse_relationship" => true, "callback" => "ws_pack_row_to_guid");
                    $user_guids = elgg_get_entities_from_relationship($site_user_options);
                    break;
                case ACCESS_FRIENDS:
                    // notify friends of subject_guid
                    $friends_options = array("type" => "user", "limit" => false, "relationship" => "friend", "relationship_guid" => $river_item->subject_guid, "callback" => "ws_pack_row_to_guid", "joins" => array("JOIN " . elgg_get_config("dbprefix") . "entity_relationships r2 ON e.guid = r2.guid_one"), "wheres" => array("(r2.relationship = 'member_of_site' AND r2.guid_two = " . elgg_get_site_entity()->getGUID() . ")"));
                    $user_guids = elgg_get_entities_from_relationship($friends_options);
                    break;
                default:
                    // probably some acl, so notify members of the acl
                    $user_guids = get_members_of_access_collection($river_item->access_id, true);
                    break;
            }
            // we found potential interested users, so push
            if (!empty($user_guids) && is_array($user_guids)) {
                $api_application_options = array("type" => "object", "subtype" => APIApplication::SUBTYPE, "limit" => false, "annotation_name" => "push_notification_service");
                if ($api_applications = elgg_get_entities_from_annotations($api_application_options)) {
                    foreach ($api_applications as $api_application) {
                        $api_application->sendPushNotification($message, $user_guids);
                    }
                }
            }
        }
    }
}

/**
 * Hook to listen to read access control requests and return all the groups you are a member of.
 */
function groups_read_acl_plugin_hook($hook, $entity_type, $returnvalue, $params)
{
    //error_log("READ: " . var_export($returnvalue));
    $user = elgg_get_logged_in_user_entity();
    if ($user) {
        // Not using this because of recursion.
        // Joining a group automatically add user to ACL,
        // So just see if they're a member of the ACL.
        //$membership = get_users_membership($user->guid);
        $members = get_members_of_access_collection($group->group_acl);
        print_r($members);
        exit;
        if ($membership) {
            foreach ($membership as $group) {
                $returnvalue[$user->guid][$group->group_acl] = elgg_echo('groups:group') . ": " . $group->name;
            }
            return $returnvalue;
        }
    }
}

<?php

/**
 * Elgg add a collection of friends
 * 
 * @package Elgg
 * @subpackage Core
 * @license http://www.gnu.org/licenses/old-licenses/gpl-2.0.html GNU Public License version 2
 * @author Curverider Ltd
 * @copyright Curverider Ltd 2008-2009
 * @link http://elgg.org/
 */
// Start engine
require_once dirname(dirname(__FILE__)) . "/engine/start.php";
// You need to be logged in for this one
gatekeeper();
//set the title
$area1 = elgg_view_title(elgg_echo('friends:collectionedit'), false);
//grab the collection id passed to the edit form
$collection_id = get_input('collection');
//get the full collection
$collection = get_access_collection($collection_id);
//get all members of the collection
$collection_members = get_members_of_access_collection($collection_id);
$area2 = elgg_view('friends/forms/edit', array('collection' => $collection, 'collection_members' => $collection_members));
// Format page
$body = elgg_view_layout('two_column_left_sidebar', $area1 . $area2);
// Draw it
page_draw(elgg_echo('friends:add'), $body);

    foreach ($NOTIFICATION_HANDLERS as $method => $foo) {
        $notify = "notify{$method}";
        $metaname = "collections_notifications_preferences_{$method}";
        $collections_preferences = $user->{$metaname};
        if (!$collections_preferences) {
            continue;
        }
        if (!is_array($collections_preferences)) {
            $collections_preferences = array($collections_preferences);
        }
        foreach ($collections_preferences as $collection_id) {
            // check the all friends notifications
            if ($collection_id == -1) {
                $options = array('relationship' => 'friend', 'relationship_guid' => $user->guid, 'limit' => 0);
                $friends = elgg_get_entities_from_relationship($options);
                foreach ($friends as $friend) {
                    if (!check_entity_relationship($user->guid, $notify, $friend->guid)) {
                        add_entity_relationship($user->guid, $notify, $friend->guid);
                    }
                }
            } else {
                $members = get_members_of_access_collection($collection_id, TRUE);
                foreach ($members as $member) {
                    if (!check_entity_relationship($user->guid, $notify, $members)) {
                        add_entity_relationship($user->guid, $notify, $member);
                    }
                }
            }
        }
    }
}

 * @link http://elgg.org/
 */
// Load Elgg engine
require_once dirname(dirname(__FILE__)) . "/engine/start.php";
global $CONFIG;
// Get callback type (list or picker)
$type = get_input('type', 'picker');
// Get list of members if applicable
/*$members = get_input('members','');
		if (!empty($members)) {
			$members = explode(',',$members);
		} else {
			$members = array();
		}*/
$collection = (int) get_input('collection', 0);
$members = get_members_of_access_collection($collection, true);
if (!$members) {
    $members = array();
}
$friendspicker = (int) get_input('friendspicker', 0);
// Get page owner (bomb out if there isn't one)
$pageowner = page_owner_entity();
if (!$pageowner) {
    forward();
    exit;
}
// Depending on the view type, launch a different view
switch ($type) {
    case 'list':
        $js_segment = elgg_view('friends/tablelistcountupdate', array('friendspicker' => $friendspicker, 'count' => sizeof($members)));
        $content = elgg_view('friends/tablelist', array('entities' => $members, 'content' => $js_segment));

/**
 * Displays a user's access collections, using the core/friends/collections view
 *
 * @param int $owner_guid The GUID of the owning user
 *
 * @return string A formatted rendition of the collections
 * @todo Move to the friends/collection.php page.
 * @access private
 */
function elgg_view_access_collections($owner_guid)
{
    if ($collections = get_user_access_collections($owner_guid)) {
        $user = get_user($owner_guid);
        if ($user) {
            $entities = $user->getFriends(array('limit' => 0));
        } else {
            $entities = array();
        }
        foreach ($collections as $key => $collection) {
            $collections[$key]->members = get_members_of_access_collection($collection->id, true);
            $collections[$key]->entities = $entities;
        }
    }
    return elgg_view('core/friends/collections', array('collections' => $collections));
}

        if (elgg_is_admin_logged_in()) {
            $form_data .= elgg_view("input/checkbox", array("name" => "all_users", "value" => "yes"));
            $form_data .= elgg_echo("group_tools:group:invite:users:all");
        }
        $form_data .= "</div>";
    }
    if ($invite_circle == "yes") {
        $tabs["circle"] = array("text" => elgg_echo("friends:collections"), "href" => "#", "rel" => "users", "priority" => 400, "onclick" => "group_tools_group_invite_switch_tab(\"circle\");");
        $form_data .= "<div id='group_tools_group_invite_circle' class='mbm'>";
        $form_data .= "<p>" . elgg_echo("collections_circle_selection") . "</p>";
        $content = get_user_access_collections(elgg_get_logged_in_user_guid());
        $collection_id = get_user_access_collections(elgg_get_logged_in_user_guid());
        $form_data .= '<select class="form-control" id="user_guid[]" name="user_guid[]">
				 <option value="">---</option>';
        foreach ($content as $key => $collection) {
            $collections = get_members_of_access_collection($collection->id, true);
            $form_data .= "<option value=";
            $coll_members = array();
            foreach ($collections as $key => $value) {
                $name = get_user($value);
                $coll_members[] = $name->guid;
            }
            $form_data .= implode(',', $coll_members);
            if ($collection->id == $collection_id) {
                $form_data .= ' selected="selected"';
            }
            $form_data .= '> ';
            $form_data .= ' ' . $collection->name . '</option>';
            $form_data .= '<br>';
        }
        $form_data .= '</select>';

/**
 * 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)
{
    global $CONFIG;
    $acl = get_access_collection($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;
}

/**
* main page handler
*/
function aga_page_handler($page, $handler)
{
    if ($page[0] == 'group') {
        $guid = $page[1];
        $db_prefix = elgg_get_config('dbprefix');
        //username
        if ($page[3]) {
            $person = get_user_by_username($page[3]);
            if (elgg_instanceof($person, 'user')) {
                $persons = array($person->guid);
                $membername = $person->name;
            }
        }
        $group = get_entity($guid);
        if (elgg_instanceof($group, 'group')) {
            $addtitle = "";
            switch ($page[2]) {
                case 'ingroup':
                    aga_tabs($handler, $guid, 'ingroup');
                    $options['joins'] = array("JOIN {$db_prefix}entities e ON e.guid = rv.object_guid");
                    $options['wheres'] = array("e.container_guid = {$guid}");
                    $options['selected'] = 'ingroup';
                    if ($persons) {
                        $options['subject_guids'] = $persons;
                        $addtitle = " (" . elgg_echo('aga:member') . ": {$membername})";
                    }
                    $titlepart = elgg_echo('aga:ingroupactivities') . $addtitle;
                    //sort order, used by member stats page
                    if ($page[4] == 'asc') {
                        $options['order_by'] = 'rv.posted ASC';
                    }
                    aga_handle_activity_page($group, $page[2], $options, $titlepart);
                    break;
                case 'outgroup':
                    aga_tabs($handler, $guid, 'outgroup');
                    $id = $group->group_acl;
                    $members = get_members_of_access_collection($id, TRUE);
                    if (!$persons) {
                        $options['subject_guids'] = $members;
                    } else {
                        $options['subject_guids'] = $persons;
                        $addtitle = " (" . elgg_echo('aga:member') . ": {$membername})";
                    }
                    //sort order, used by member stats page
                    if ($page[4] == 'asc') {
                        $options['order_by'] = 'rv.posted ASC';
                    }
                    $titlepart = elgg_echo('aga:outgroupactivities') . $addtitle;
                    $options['selected'] = 'outgroup';
                    aga_handle_activity_page($group, $page[2], $options, $titlepart);
                    break;
                case 'members':
                    aga_tabs($handler, $guid, 'members');
                    aga_handle_members_page($group, $page[3]);
                    break;
                case 'stats':
                    aga_tabs($handler, $guid, 'stats');
                    aga_handle_stats_page($group);
                    break;
                default:
                    return false;
            }
            return true;
        } else {
            //this is not an actual group - stop right here
            return false;
        }
    } else {
        //it never even claimed to be a group so why are we even here?
        return false;
    }
}

/**
 * Displays a user's access collections, using the friends/collections view
 *
 * @param int $owner_guid The GUID of the owning user
 * @return string A formatted rendition of the collections
 */
function elgg_view_access_collections($owner_guid)
{
    if ($collections = get_user_access_collections($owner_guid)) {
        foreach ($collections as $key => $collection) {
            $collections[$key]->members = get_members_of_access_collection($collection->id, true);
            $collections[$key]->entities = get_user_friends($owner_guid, "", 9999);
        }
    }
    return elgg_view('friends/collections', array('collections' => $collections));
}

if ($siteadmin_guid && elgg_is_admin_logged_in()) {
    $from = $siteadmin_guid;
}
if (!$recipient_guid && !$collection_guid) {
    register_error(elgg_echo("messages:user:blank"));
    forward("messages/compose");
}
// Make sure the message field, send to field and title are not blank
if (!$body || !$subject) {
    register_error(elgg_echo("messages:blank"));
    forward("messages/compose");
}
elgg_make_sticky_form('messages');
// Send to collection of friends
if (!empty($collection_guid)) {
    $collection = get_members_of_access_collection($collection_guid, false);
    foreach ($collection as $member) {
        if (!$member->isBanned()) {
            $result += messages_send($subject, $body, $member->guid, $from, $reply, true, true);
        }
    }
}
if (!empty($recipient_guid)) {
    $user = get_user($recipient_guid);
    if (!$user) {
        register_error(elgg_echo("messages:user:nonexist"));
        forward("messages/compose");
    }
    $result = messages_send($subject, $body, $recipient_guid, $from, $reply, true, true);
}
// Save 'send' the message

    $title = $vars['collection']->name;
    $highlight = 'default';
} else {
    $title = "";
    $highlight = 'all';
}
echo "<div class=\"mtm\"><label>" . elgg_echo("friends:collectionname") . "<br/>";
echo elgg_view("input/text", array("name" => "collection_name", "value" => $title));
echo "</label></div>";
echo "<div>";
if ($vars['collection_members']) {
    echo elgg_echo("friends:collectionfriends") . "<br />";
    foreach ($vars['collection_members'] as $mem) {
        echo elgg_view_entity_icon($mem, 'tiny');
        echo $mem->name;
    }
}
echo "</div>";
$members = get_members_of_access_collection($vars['collection']->id, true);
if (!$members) {
    $members = array();
}
echo "<div><label>" . elgg_echo("friends:addfriends") . "</label>";
echo elgg_view('input/friendspicker', array('entities' => $vars['friends'], 'name' => 'friends_collection', 'value' => $members, 'highlight' => $highlight, 'collection_id' => $vars['collection']->id, 'formtarget' => $site_url . 'action/friends/collections/edit'));
echo "</div>";
echo '<div class="elgg-foot">';
if (isset($vars['collection'])) {
    echo elgg_view('input/hidden', array('name' => 'collection_id', 'value' => $vars['collection']->id));
}
//echo elgg_view('input/submit', array('name' => 'submit', 'value' => elgg_echo('save'), 'class' => 'btn btn-primary'));
echo '</div>';

 public function testAddMemberToACLRemoveMember()
 {
     // create a new user to check against
     $user = new \ElggUser();
     $user->username = 'access_test_user';
     $user->save();
     $acl_id = create_access_collection('test acl');
     $result = add_user_to_access_collection($user->guid, $acl_id);
     $this->assertTrue($result);
     if ($result) {
         $this->assertTrue($user->delete());
         // since there are no more members this should return false
         $acl_members = get_members_of_access_collection($acl_id, true);
         $this->assertFalse($acl_members);
     }
     delete_access_collection($acl_id);
 }

/**
 * Delete access collection hook
 *
 * @param string $hook   'access:collections:deletecollection'
 * @param string $type   'collection'
 * @param mixed  $return Hook result
 * @param array  $params Hook params
 * @return void
 */
function elgg_solr_collection_delete($hook, $type, $return, $params)
{
    $collection_id = elgg_extract('collection_id', $params);
    $members = get_members_of_access_collection($collection_id, true);
    foreach ($members as $member_guid) {
        elgg_solr_defer_index_update($member_guid);
    }
}

function pleio_api_users_with_access_device_token($river)
{
    $list = array();
    $subject = get_entity($river->subject_guid);
    $object = get_entity($river->object_guid);
    $wheres = array();
    $joins = array();
    // don't return same object or subject
    $wheres[] = sprintf("e.guid NOT IN (%d, %d, %d, %d)", $object->guid, $object->owner_guid, $subject->guid, $subject->owner_guid);
    $site_guid = $object->site_guid;
    // override site_guid if object is site_guid
    if ($object instanceof Subsite || $object instanceof ElggSite) {
        $site_guid = $object->guid;
    }
    // add access_id specific wheres to determine possible receivers
    $more = false;
    switch ($object->access_id) {
        case ACCESS_DEFAULT:
        case ACCESS_LOGGED_IN:
        case ACCESS_PUBLIC:
            if ($object->type == "user") {
                //only friends $object->guid
                $more = elgg_get_entity_relationship_where_sql('e.guid', 'friend', $object->guid, 1);
            } elseif ($object && $object->container_guid && $object->container_guid != $object->owner_guid && ($container = get_entity($object->container_guid) && $container instanceof ElggGroup)) {
                // only group $object->container_guid
                $more = elgg_get_entity_relationship_where_sql('e.guid', 'member', $object->container_guid, 1);
            } elseif ($site_guid > 1) {
                //only subsite $site_guid
                $more = elgg_get_entity_relationship_where_sql('e.guid', 'member_of_site', $site_guid, 1);
            } else {
                // pleio has too many users to update everyone, so only friends $object->owner_guid
                $more = elgg_get_entity_relationship_where_sql('e.guid', 'friend', $object->owner_guid, 1);
            }
            break;
        case ACCESS_FRIENDS:
            //only friends $object->owner_guid
            $more = elgg_get_entity_relationship_where_sql('e.guid', 'friend', $object->owner_guid, 1);
            break;
        case ACCESS_PRIVATE:
            return array();
        default:
            $users = get_members_of_access_collection($object->access_id, 1);
            $wheres[] = "e.guid IN (" . implode(", ", $users) . ")";
    }
    if ($more) {
        $wheres = array_merge($wheres, $more["wheres"]);
        $joins = array_merge($joins, $more["joins"]);
    }
    // only select users that have a device_token
    $more = elgg_get_entity_private_settings_where_sql('e', array(), array(), array(array('name' => 'device_token', 'value' => 1, 'operand' => 'IS NOT NULL AND 1 = ')));
    $wheres = array_merge($wheres, $more["wheres"]);
    $joins = array_merge($joins, $more["joins"]);
    $options = array('type' => 'user', 'limit' => 100, 'wheres' => $wheres, 'joins' => $joins, 'site_guid' => ELGG_ENTITIES_ANY_VALUE);
    $users = elgg_get_entities($options);
    foreach ($users as $user) {
        $list[$user->guid] = array("device_token" => $user->getPrivateSetting('device_token'), "device" => $user->getPrivateSetting('device'));
    }
    return $list;
}