Use.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.
 */

/**
 * Imports blocks defined in another template into the current template.
 *
 * <pre>
 * {% extends "base.html" %}
 *
 * {% use "blocks.html" %}
 *
 * {% block title %}{% endblock %}
 * {% block content %}{% endblock %}
 * </pre>
 *
 * @see http://www.twig-project.org/doc/templates.html#horizontal-reuse for details.
 */
class Twig_TokenParser_Use extends Twig_TokenParser {

  /**
   * Parses a token and returns a node.
   *
   * @param Twig_Token $token A Twig_Token instance
   *
   * @return Twig_NodeInterface A Twig_NodeInterface instance
   */
  public function parse(Twig_Token $token) {
    $template = $this->parser
      ->getExpressionParser()
      ->parseExpression();
    if (!$template instanceof Twig_Node_Expression_Constant) {
      throw new Twig_Error_Syntax('The template references in a "use" statement must be a string.', $token
        ->getLine());
    }
    $stream = $this->parser
      ->getStream();
    $targets = array();
    if ($stream
      ->test('with')) {
      $stream
        ->next();
      do {
        $name = $stream
          ->expect(Twig_Token::NAME_TYPE)
          ->getValue();
        $alias = $name;
        if ($stream
          ->test('as')) {
          $stream
            ->next();
          $alias = $stream
            ->expect(Twig_Token::NAME_TYPE)
            ->getValue();
        }
        $targets[$name] = new Twig_Node_Expression_Constant($alias, -1);
        if (!$stream
          ->test(Twig_Token::PUNCTUATION_TYPE, ',')) {
          break;
        }
        $stream
          ->next();
      } while (true);
    }
    $stream
      ->expect(Twig_Token::BLOCK_END_TYPE);
    $this->parser
      ->addTrait(new Twig_Node(array(
      'template' => $template,
      'targets' => new Twig_Node($targets),
    )));
    return null;
  }

  /**
   * Gets the tag name associated with this token parser.
   *
   * @return string The tag name
   */
  public function getTag() {
    return 'use';
  }

}