/**
 * Handler called by trigger_plugin_hook on the "export" event.
 *
 * @param string $hook        export
 * @param string $entity_type all
 * @param mixed  $returnvalue Previous hook return value
 * @param array  $params      Parameters
 *
 * @elgg_event_handler export all
 * @return mixed
 * @throws InvalidParameterException
 * @access private
 * @deprecated 1.9
 */
function export_relationship_plugin_hook($hook, $entity_type, $returnvalue, $params)
{
    // Sanity check values
    if (!is_array($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;
}

/**
 * Handler called by trigger_plugin_hook on the "export" event.
 *
 * @param string $hook        export
 * @param string $entity_type all
 * @param mixed  $returnvalue Previous hook return value
 * @param array  $params      Parameters
 *
 * @elgg_event_handler export all
 * @return mixed
 * @access private
 */
function export_relationship_plugin_hook($hook, $entity_type, $returnvalue, $params)
{
    global $CONFIG;
    // Sanity check values
    if (!is_array($params) && !isset($params['guid'])) {
        throw new InvalidParameterException(elgg_echo('InvalidParameterException:GUIDNotForExport'));
    }
    if (!is_array($returnvalue)) {
        throw new InvalidParameterException(elgg_echo('InvalidParameterException:NonArrayReturnValue'));
    }
    $guid = (int) $params['guid'];
    $result = get_entity_relationships($guid);
    if ($result) {
        foreach ($result as $r) {
            $returnvalue[] = $r->export();
        }
    }
    return $returnvalue;
}

/**
 * Elgg Entity export.
 * Displays an entity using the current view.
 *
 * @package Elgg
 * @subpackage Core
 * @author Curverider Ltd
 * @link http://elgg.org/
 */
$entity = $vars['entity'];
if (!$entity) {
    throw new InvalidParameterException(elgg_echo('InvalidParameterException:NoEntityFound'));
}
$metadata = get_metadata_for_entity($entity->guid);
$annotations = get_annotations($entity->guid);
$relationships = get_entity_relationships($entity->guid);
$exportable_values = $entity->getExportableValues();
?>
<div>
<h2><?php 
echo elgg_echo('Entity');
?>
</h2>
	<?php 
foreach ($entity as $k => $v) {
    if (in_array($k, $exportable_values) || isadminloggedin()) {
        ?>
			<p class="margin_none"><b><?php 
        echo $k;
        ?>
: </b><?php 

$user_guid = elgg_get_logged_in_user_guid();
// load original file object
$file = new ElggFile($file_guid);
if (!$file) {
    if ($lock) {
        register_error(elgg_echo('odt_editor:error:file_removed'));
    }
    forward(REFERER);
}
// user must be able to edit file
if (!$file->canEdit()) {
    register_error(elgg_echo('You do no longer have write access to the file that is edited.'));
    forward(REFERER);
}
// save folder guid in parameter to make sure file_tools_object_handler does not overwrite the relationship
$relationships = get_entity_relationships($file->guid, FILE_TOOLS_RELATIONSHIP, true);
if (elgg_is_active_plugin('file_tools') && count($relationships) > 0) {
    set_input('folder_guid', $relationships[0]->guid_one);
}
// recreate lock, user closed window but cancelled
if ($lock_set && !odt_editor_locking_is_locked($file)) {
    trigger_error("Restored lock", E_USER_WARNING);
    odt_editor_locking_create_lock($file, $user_guid, $lock_guid);
    forward(REFERER);
}
// check for lost lock
if (odt_editor_locking_lock_guid($file) != $lock_guid) {
    $lock_owner_guid = odt_editor_locking_lock_owner_guid($file);
    if ($lock_owner_guid != $user_guid) {
        $locking_user = get_entity($lock_owner_guid);
        $locking_user_name = $locking_user ? $locking_user->name : elgg_echo("odt_editor:unknown_user");

/**
 * Check if a user has a block relationship with an entity
 *
 * @param int $entity_guid the entity to check
 * @param int $user_guid   the user to check for (default: current user)
 *
 * @return bool
 */
function content_subscriptions_check_block_subscription($entity_guid, $user_guid = 0)
{
    static $user_cache;
    $entity_guid = sanitise_int($entity_guid, false);
    $user_guid = sanitise_int($user_guid, false);
    if (empty($user_guid)) {
        $user_guid = elgg_get_logged_in_user_guid();
    }
    if (empty($entity_guid) || empty($user_guid)) {
        return false;
    }
    if (!isset($user_cache)) {
        $user_cache = [];
    }
    if (!isset($user_cache[$user_guid])) {
        $user_cache[$user_guid] = [];
        $relationships = get_entity_relationships($user_guid);
        if (!empty($relationships)) {
            foreach ($relationships as $relationship) {
                if ($relationship->relationship === CONTENT_SUBSCRIPTIONS_BLOCK) {
                    $user_cache[$user_guid][] = (int) $relationship->guid_two;
                }
            }
        }
    }
    return in_array($entity_guid, $user_cache[$user_guid]);
}

 /**
  * Hook to export relationship entities for search
  *
  * @param string $hook        the name of the hook
  * @param string $type        the type of the hook
  * @param string $returnvalue current return value
  * @param array  $params      supplied params
  *
  * @return void
  */
 public static function entityRelationshipsToObject($hook, $type, $returnvalue, $params)
 {
     if (!elgg_in_context('search:index')) {
         return;
     }
     $entity = elgg_extract('entity', $params);
     if (!$entity) {
         return;
     }
     $relationships = get_entity_relationships($entity->getGUID());
     if (empty($relationships)) {
         return;
     }
     $result = [];
     foreach ($relationships as $relationship) {
         $result[] = ['id' => (int) $relationship->id, 'time_created' => date('c', $relationship->time_created), 'guid_one' => (int) $relationship->guid_one, 'guid_two' => (int) $relationship->guid_two, 'relationship' => $relationship->relationship];
     }
     $returnvalue->relationships = $result;
     return $returnvalue;
 }

<?php

/**
 * whoviewedme index
 *
 */
$title = elgg_echo('whoviewedme');
$options = array('type' => 'user', 'full_view' => false);
$options['relationship'] = 'viewed';
$options['inverse_relationship'] = true;
$options['relationship_guid'] = elgg_get_logged_in_user_guid();
//$content = elgg_list_entities_from_relationship($options);
$rels = get_entity_relationships(elgg_get_logged_in_user_guid());
if (!$rels) {
    $content = elgg_echo("whoviewedme:nobody");
} else {
    $content = "";
    foreach ($rels as $key => $rel) {
        $user = get_user($rel->guid_two);
        if (!$user) {
            continue;
        }
        $content .= elgg_view_entity($user);
        $content .= elgg_view_friendly_time($rel->time_created);
        //$content.= "</br>".$rel->guid_two;
    }
}
$params = array('content' => $content, 'title' => $title, 'filter_override' => "");
$body = elgg_view_layout('content', $params);
echo elgg_view_page($title, $body);

<?php

namespace hypeJunction\Wall;

use ElggBatch;
$ia = elgg_set_ignore_access(true);
/**
 * Wall owner should become the container of the wall post
 * wall_owner relationship should go away
 */
$wall_posts = new ElggBatch('elgg_get_entities_from_relationship', array('types' => 'object', 'subtypes' => 'hjwall', 'relationship' => 'wall_owner', 'limit' => false));
foreach ($wall_posts as $wall_post) {
    $relationships = get_entity_relationships($wall_post->guid, true);
    foreach ($relationships as $relationship) {
        if ($relationship->relationship !== 'wall_owner') {
            continue;
        }
        if ($relationship->guid_one !== $wall_post->container_guid) {
            $wall_post->container_guid = $relationship->guid_one;
            if ($wall_post->save()) {
                $relationship->delete();
            }
        }
    }
}
/**
 * Convert attachment metadata to 'attached' relationship for entities
 * and 'html' metadata for the rest
 */
$wall_posts = new ElggBatch('elgg_get_entities_from_metadata', array('types' => 'object', 'subtypes' => 'hjwall', 'metadata_names' => 'attachment', 'limit' => false));
foreach ($wall_posts as $wall_post) {

 public function upgrade20140211()
 {
     $ia = elgg_set_ignore_access(true);
     /**
      * Wall owner should become the container of the wall post
      * wall_owner relationship should go away
      */
     $wall_posts = new \ElggBatch('elgg_get_entities_from_relationship', array('types' => 'object', 'subtypes' => 'hjwall', 'relationship' => 'wall_owner', 'limit' => false));
     foreach ($wall_posts as $wall_post) {
         $relationships = get_entity_relationships($wall_post->guid, true);
         foreach ($relationships as $relationship) {
             if ($relationship->relationship !== 'wall_owner') {
                 continue;
             }
             if ($relationship->guid_one !== $wall_post->container_guid) {
                 $wall_post->container_guid = $relationship->guid_one;
                 if ($wall_post->save()) {
                     $relationship->delete();
                 }
             }
         }
     }
     /**
      * Convert attachment metadata to 'attached' relationship for entities
      * and 'html' metadata for the rest
      */
     $wall_posts = new \ElggBatch('elgg_get_entities_from_metadata', array('types' => 'object', 'subtypes' => 'hjwall', 'metadata_names' => 'attachment', 'limit' => false));
     foreach ($wall_posts as $wall_post) {
         $attachment = $wall_post->attachment;
         if (is_numeric($attachment) && ($attached_entity = get_entity($attachment))) {
             add_entity_relationship($attached_entity->guid, 'attached', $wall_post->guid);
         } else {
             $wall_post->html = $attachment;
         }
         unset($wall_post->attachment);
     }
     /**
      * Convert 'hjfile' to 'file'
      */
     $subtypeIdFrom = add_subtype('object', 'hjfile');
     $subtypeIdTo = add_subtype('object', 'file');
     $dbprefix = elgg_get_config('dbprefix');
     $query = "\tUPDATE {$dbprefix}entities e\n\t\t\t\tJOIN {$dbprefix}metadata md ON md.entity_guid = e.guid\n\t\t\t\tJOIN {$dbprefix}metastrings msn ON msn.id = md.name_id\n\t\t\t\tJOIN {$dbprefix}metastrings msv ON msv.id = md.value_id\n\t\t\t\tSET e.subtype = {$subtypeIdTo}\n\t\t\t\tWHERE e.subtype = {$subtypeIdFrom} AND msn.string = 'handler' AND msv.string = 'hjwall' ";
     $wall_files = new \ElggBatch('elgg_get_entities_from_metadata', array('types' => 'object', 'subtypes' => 'file', 'metadata_name_value_pairs' => array('name' => 'handler', 'value' => 'hjwall'), 'limit' => false));
     foreach ($wall_files as $file) {
         // Regenerate icons
         if ($file->simpletype == 'image') {
             $thumb_sizes = array('tiny' => 16, 'small' => 25, 'medium' => 40, 'large' => 100, 'preview' => 250, 'master' => 500, 'full' => 1024);
             foreach ($thumb_sizes as $ths => $dim) {
                 $thumb = new ElggFile();
                 $thumb->setFilenameOnFilestore("hjfile/{$file->getGUID()}{$ths}.jpg");
                 unlink($thumb->getFilenameOnFilestore());
             }
             $file->icontime = time();
             $thumbnail = get_resized_image_from_existing_file($file->getFilenameOnFilestore(), 60, 60, true);
             if ($thumbnail) {
                 $thumb = new ElggFile();
                 $thumb->setFilename($prefix . "thumb" . $filestorename);
                 $thumb->open("write");
                 $thumb->write($thumbnail);
                 $thumb->close();
                 $file->thumbnail = $prefix . "thumb" . $filestorename;
                 unset($thumbnail);
             }
             $thumbsmall = get_resized_image_from_existing_file($file->getFilenameOnFilestore(), 153, 153, true);
             if ($thumbsmall) {
                 $thumb->setFilename($prefix . "smallthumb" . $filestorename);
                 $thumb->open("write");
                 $thumb->write($thumbsmall);
                 $thumb->close();
                 $file->smallthumb = $prefix . "smallthumb" . $filestorename;
                 unset($thumbsmall);
             }
             $thumblarge = get_resized_image_from_existing_file($file->getFilenameOnFilestore(), 600, 600, false);
             if ($thumblarge) {
                 $thumb->setFilename($prefix . "largethumb" . $filestorename);
                 $thumb->open("write");
                 $thumb->write($thumblarge);
                 $thumb->close();
                 $file->largethumb = $prefix . "largethumb" . $filestorename;
                 unset($thumblarge);
             }
         }
     }
     /**
      * Set file folder guids as plugin setting
      */
     $folders = new \ElggBatch('elgg_get_entities_from_metadata', array('types' => 'object', 'subtypes' => 'hjfilefolder', 'metadata_name_value_pairs' => array('name' => 'handler', 'value' => 'hjwall'), 'limit' => false));
     foreach ($folders as $folder) {
         elgg_set_plugin_user_setting('wall_collection', $folder->guid, $folder->owner_guid, 'hypeWall');
     }
     /**
      * Convert 'hjfilefolder' to 'wall_collection'
      */
     $subtypeIdFrom = add_subtype('object', 'hjfilefolder');
     $subtypeIdTo = add_subtype('object', 'wallcollection');
     $dbprefix = elgg_get_config('dbprefix');
     $query = "\tUPDATE {$dbprefix}entities e\n\t\t\t\tJOIN {$dbprefix}metadata md ON md.entity_guid = e.guid\n\t\t\t\tJOIN {$dbprefix}metastrings msn ON msn.id = md.name_id\n\t\t\t\tJOIN {$dbprefix}metastrings msv ON msv.id = md.value_id\n\t\t\t\tSET e.subtype = {$subtypeIdTo}\n\t\t\t\tWHERE e.subtype = {$subtypeIdFrom} AND msn.string = 'handler' AND msv.string = 'hjwall' ";
     elgg_set_ignore_access($ia);
 }

 // rename display name to inactive
 $user->name = elgg_echo('member_selfdelete:inactive:user');
 // reset avatar to system default
 unset($user->icontime);
 // delete all metadata on the user - all profile fields etc.
 // includes anything set by any other plugins
 // essentially resets to clean user
 $metadata = elgg_get_metadata(array('guid' => $user->guid, 'limit' => false));
 if (is_array($metadata)) {
     foreach ($metadata as $data) {
         $data->delete();
     }
 }
 // delete all relationships in both directions
 $relationships1 = get_entity_relationships($user->guid, FALSE);
 $relationships2 = get_entity_relationships($user->guid, TRUE);
 $relationships = array_merge($relationships1, $relationships2);
 if (is_array($relationships)) {
     foreach ($relationships as $relationship) {
         if ($relationship->relationship == 'member_of_site') {
             continue;
         }
         $relationship->delete();
     }
 }
 // delete all annotations on the user
 $annotations = elgg_get_annotations(array('guids' => array($user->guid)));
 if (is_array($annotations)) {
     foreach ($annotations as $annotation) {
         $annotation->delete();
     }

 public static function getRelationships($entity_guid)
 {
     $return = array();
     $relation = get_entity_relationships($entity_guid);
     if ($relation) {
         foreach ($relation as $data) {
             $return[$data->id]['relationship'] = $data->relationship;
             $return[$data->id]['guid_one'] = $data->guid_one;
             $return[$data->id]['guid_two'] = $data->guid_two;
         }
     }
     return $return;
 }