GuardTokenParser.php

<?php


/*
 * This file is part of Twig.
 *
 * (c) Fabien Potencier
 *
 * 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\EmptyNode;
use Twig\Node\Node;
use Twig\Node\Nodes;
use Twig\Token;

/**
 * @internal
 */
final class GuardTokenParser extends AbstractTokenParser {
    public function parse(Token $token) : Node {
        $stream = $this->parser
            ->getStream();
        $typeToken = $stream->expect(Token::NAME_TYPE);
        if (!in_array($typeToken->getValue(), [
            'function',
            'filter',
            'test',
        ])) {
            throw new SyntaxError(\sprintf('Supported guard types are function, filter and test, "%s" given.', $typeToken->getValue()), $typeToken->getLine(), $stream->getSourceContext());
        }
        $method = 'get' . $typeToken->getValue();
        $nameToken = $stream->expect(Token::NAME_TYPE);
        $exists = null !== $this->parser
            ->getEnvironment()
            ->{$method}($nameToken->getValue());
        $stream->expect(Token::BLOCK_END_TYPE);
        if ($exists) {
            $body = $this->parser
                ->subparse([
                $this,
                'decideGuardFork',
            ]);
        }
        else {
            $body = new EmptyNode();
            $this->parser
                ->subparseIgnoreUnknownTwigCallables([
                $this,
                'decideGuardFork',
            ]);
        }
        $else = new EmptyNode();
        if ('else' === $stream->next()
            ->getValue()) {
            $stream->expect(Token::BLOCK_END_TYPE);
            $else = $this->parser
                ->subparse([
                $this,
                'decideGuardEnd',
            ], true);
        }
        $stream->expect(Token::BLOCK_END_TYPE);
        return new Nodes([
            $exists ? $body : $else,
        ]);
    }
    public function decideGuardFork(Token $token) : bool {
        return $token->test([
            'else',
            'endguard',
        ]);
    }
    public function decideGuardEnd(Token $token) : bool {
        return $token->test([
            'endguard',
        ]);
    }
    public function getTag() : string {
        return 'guard';
    }

}