Elgg-Lorea-Hydra/mod/friend_request/actions/revoke.php

<?php
	
$friend_guid = (int) get_input('guid');
$friend = get_user($friend_guid);
if (empty($friend)) {
	register_error(elgg_echo('error:missing_data'));
	forward(REFERER);
}

$user = elgg_get_logged_in_user_entity();

if (remove_entity_relationship($user->getGUID(), 'friendrequest', $friend->getGUID())) {
	system_message(elgg_echo('friend_request:revoke:success'));
} else {
	register_error(elgg_echo('friend_request:revoke:fail'));
}

forward(REFERER);