Extends.php

<?php

/*
 * This file is part of Twig.
 *
 * (c) 2009 Fabien Potencier
 * (c) 2009 Armin Ronacher
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

/**
 * Extends a template by another one.
 *
 * <pre>
 *  {% extends "base.html" %}
 * </pre>
 */
class Twig_TokenParser_Extends 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 $token) {
    if (!$this->parser
      ->isMainScope()) {
      throw new Twig_Error_Syntax('Cannot extend from a block', $token
        ->getLine(), $this->parser
        ->getFilename());
    }
    if (null !== $this->parser
      ->getParent()) {
      throw new Twig_Error_Syntax('Multiple extends tags are forbidden', $token
        ->getLine(), $this->parser
        ->getFilename());
    }
    $this->parser
      ->setParent($this->parser
      ->getExpressionParser()
      ->parseExpression());
    $this->parser
      ->getStream()
      ->expect(Twig_Token::BLOCK_END_TYPE);
    return null;
  }

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

}