BlockTokenParser.php

<?php


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

use Twig\Error\SyntaxError;
use Twig\Node\BlockNode;
use Twig\Node\BlockReferenceNode;
use Twig\Node\EmptyNode;
use Twig\Node\Node;
use Twig\Node\Nodes;
use Twig\Node\PrintNode;
use Twig\Token;

/**
 * Marks a section of a template as being reusable.
 *
 *  {% block head %}
 *    <link rel="stylesheet" href="style.css" />
 *    <title>{% block title %}{% endblock %} - My Webpage</title>
 *  {% endblock %}
 *
 * @internal
 */
final class BlockTokenParser extends AbstractTokenParser {
    public function parse(Token $token) : Node {
        $lineno = $token->getLine();
        $stream = $this->parser
            ->getStream();
        $name = $stream->expect(Token::NAME_TYPE)
            ->getValue();
        $this->parser
            ->setBlock($name, $block = new BlockNode($name, new EmptyNode(), $lineno));
        $this->parser
            ->pushLocalScope();
        $this->parser
            ->pushBlockStack($name);
        if ($stream->nextIf(Token::BLOCK_END_TYPE)) {
            $body = $this->parser
                ->subparse([
                $this,
                'decideBlockEnd',
            ], true);
            if ($token = $stream->nextIf(Token::NAME_TYPE)) {
                $value = $token->getValue();
                if ($value != $name) {
                    throw new SyntaxError(\sprintf('Expected endblock for block "%s" (but "%s" given).', $name, $value), $stream->getCurrent()
                        ->getLine(), $stream->getSourceContext());
                }
            }
        }
        else {
            $body = new Nodes([
                new PrintNode($this->parser
                    ->getExpressionParser()
                    ->parseExpression(), $lineno),
            ]);
        }
        $stream->expect(Token::BLOCK_END_TYPE);
        $block->setNode('body', $body);
        $this->parser
            ->popBlockStack();
        $this->parser
            ->popLocalScope();
        return new BlockReferenceNode($name, $lineno);
    }
    public function decideBlockEnd(Token $token) : bool {
        return $token->test('endblock');
    }
    public function getTag() : string {
        return 'block';
    }

}