<?php
 
 /*
  * This file is part of the Symfony package.
  *
  * (c) Fabien Potencier <fabien@symfony.com>
  *
  * For the full copyright and license information, please view the LICENSE
  * file that was distributed with this source code.
  */
 
 namespace Symfony\Component\Translation;
 
 /**
  * MetadataAwareInterface.
  *
  * @author Fabien Potencier <fabien@symfony.com>
  */
 interface MetadataAwareInterface
 {
     /**
      * Gets metadata for the given domain and key.
      *
      * Passing an empty domain will return an array with all metadata indexed by
      * domain and then by key. Passing an empty key will return an array with all
      * metadata for the given domain.
      *
      * @param string $key    The key
      * @param string $domain The domain name
      *
      * @return mixed The value that was set or an array with the domains/keys or null
      */
     public function getMetadata($key = '', $domain = 'messages');
 
     /**
      * Adds metadata to a message domain.
      *
      * @param string $key    The key
      * @param mixed  $value  The value
      * @param string $domain The domain name
      */
     public function setMetadata($key, $value, $domain = 'messages');
 
     /**
      * Deletes metadata for the given key and domain.
      *
      * Passing an empty domain will delete all metadata. Passing an empty key will
      * delete all metadata for the given domain.
      *
      * @param string $key    The key
      * @param string $domain The domain name
      */
     public function deleteMetadata($key = '', $domain = 'messages');
 }