Chain.php

<?php

/*
 * This file is part of Twig.
 *
 * (c) 2011 Fabien Potencier
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

/**
 * Loads templates from other loaders.
 *
 * @package twig
 * @author  Fabien Potencier <fabien@symfony.com>
 */
class Twig_Loader_Chain implements Twig_LoaderInterface {
  protected $loaders;

  /**
   * Constructor.
   *
   * @param Twig_LoaderInterface[] $loaders An array of loader instances
   */
  public function __construct(array $loaders = array()) {
    $this->loaders = array();
    foreach ($loaders as $loader) {
      $this
        ->addLoader($loader);
    }
  }

  /**
   * Adds a loader instance.
   *
   * @param Twig_LoaderInterface $loader A Loader instance
   */
  public function addLoader(Twig_LoaderInterface $loader) {
    $this->loaders[] = $loader;
  }

  /**
   * Gets the source code of a template, given its name.
   *
   * @param string $name The name of the template to load
   *
   * @return string The template source code
   */
  public function getSource($name) {
    foreach ($this->loaders as $loader) {
      try {
        return $loader
          ->getSource($name);
      } catch (Twig_Error_Loader $e) {
      }
    }
    throw new Twig_Error_Loader(sprintf('Template "%s" is not defined.', $name));
  }

  /**
   * Gets the cache key to use for the cache for a given template name.
   *
   * @param string $name The name of the template to load
   *
   * @return string The cache key
   */
  public function getCacheKey($name) {
    foreach ($this->loaders as $loader) {
      try {
        return $loader
          ->getCacheKey($name);
      } catch (Twig_Error_Loader $e) {
      }
    }
    throw new Twig_Error_Loader(sprintf('Template "%s" is not defined.', $name));
  }

  /**
   * Returns true if the template is still fresh.
   *
   * @param string    $name The template name
   * @param timestamp $time The last modification time of the cached template
   */
  public function isFresh($name, $time) {
    foreach ($this->loaders as $loader) {
      try {
        return $loader
          ->isFresh($name, $time);
      } catch (Twig_Error_Loader $e) {
      }
    }
    throw new Twig_Error_Loader(sprintf('Template "%s" is not defined.', $name));
  }

}