<?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\Loader;
 
 use Symfony\Component\Translation\MessageCatalogue;
 
 /**
  * ArrayLoader loads translations from a PHP array.
  *
  * @author Fabien Potencier <fabien@symfony.com>
  */
 class ArrayLoader implements LoaderInterface
 {
     /**
      * {@inheritdoc}
      */
     public function load($resource, $locale, $domain = 'messages')
     {
         $this->flatten($resource);
         $catalogue = new MessageCatalogue($locale);
         $catalogue->add($resource, $domain);
 
         return $catalogue;
     }
 
     /**
      * Flattens an nested array of translations.
      *
      * The scheme used is:
      *   'key' => ['key2' => ['key3' => 'value']]
      * Becomes:
      *   'key.key2.key3' => 'value'
      *
      * This function takes an array by reference and will modify it
      *
      * @param array  &$messages The array that will be flattened
      * @param array  $subnode   Current subnode being parsed, used internally for recursive calls
      * @param string $path      Current path being parsed, used internally for recursive calls
      */
     private function flatten(array &$messages, array $subnode = null, $path = null)
     {
         if (null === $subnode) {
             $subnode = &$messages;
         }
         foreach ($subnode as $key => $value) {
             if (\is_array($value)) {
                 $nodePath = $path ? $path.'.'.$key : $key;
                 $this->flatten($messages, $value, $nodePath);
                 if (null === $path) {
                     unset($messages[$key]);
                 }
             } elseif (null !== $path) {
                 $messages[$path.'.'.$key] = $value;
             }
         }
     }
 }