<?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.

 */

/**

 * Marks a section of a template as being reusable.

 *

 * <pre>

 *  {% block head %}

 *    <link rel="stylesheet" href="style.css" />

 *    <title>{% block title %}{% endblock %} - My Webpage</title>

 *  {% endblock %}

 * </pre>

 */

class Twig_TokenParser_Block 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)

    {

        $lineno = $token->getLine();

        $stream = $this->parser->getStream();

        $name = $stream->expect(Twig_Token::NAME_TYPE)->getValue();

        if ($this->parser->hasBlock($name)) {

            throw new Twig_Error_Syntax("The block '$name' has already been defined", $lineno);

        }

        $this->parser->pushLocalScope();

        $this->parser->pushBlockStack($name);

        if ($stream->test(Twig_Token::BLOCK_END_TYPE)) {

            $stream->next();

            $body = $this->parser->subparse(array($this, 'decideBlockEnd'), true);

            if ($stream->test(Twig_Token::NAME_TYPE)) {

                $value = $stream->next()->getValue();

                if ($value != $name) {

                    throw new Twig_Error_Syntax(sprintf("Expected endblock for block '$name' (but %s given)", $value), $lineno);

                }

            }

        } else {

            $body = new Twig_Node(array(

                new Twig_Node_Print($this->parser->getExpressionParser()->parseExpression(), $lineno),

            ));

        }

        $stream->expect(Twig_Token::BLOCK_END_TYPE);

        $block = new Twig_Node_Block($name, $body, $lineno);

        $this->parser->setBlock($name, $block);

        $this->parser->popBlockStack();

        $this->parser->popLocalScope();

        return new Twig_Node_BlockReference($name, $lineno, $this->getTag());

    }

    public function decideBlockEnd(Twig_Token $token)

    {

        return $token->test('endblock');

    }

    /**

     * Gets the tag name associated with this token parser.

     *

     * @param string The tag name

     */

    public function getTag()

    {

        return 'block';

    }

}