<?php
declare(strict_types=1);
/*
* This file is part of the league/commonmark package.
*
* (c) Colin O'Dell <[email protected]>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace League\CommonMark\Extension\FrontMatter;
use League\CommonMark\Extension\FrontMatter\Data\FrontMatterDataParserInterface;
use League\CommonMark\Extension\FrontMatter\Input\MarkdownInputWithFrontMatter;
use League\CommonMark\Parser\Cursor;
final class FrontMatterParser implements FrontMatterParserInterface
{
/** @psalm-readonly */
private FrontMatterDataParserInterface $frontMatterParser;
private const REGEX_FRONT_MATTER = '/^---\\R.*?\\R---\\R/s';
public function __construct(FrontMatterDataParserInterface $frontMatterParser)
{
$this->frontMatterParser = $frontMatterParser;
}
public function parse(string $markdownContent): MarkdownInputWithFrontMatter
{
$cursor = new Cursor($markdownContent);
// Locate the front matter
$frontMatter = $cursor->match(self::REGEX_FRONT_MATTER);
if ($frontMatter === null) {
return new MarkdownInputWithFrontMatter($markdownContent);
}
// Trim the last line (ending ---s and newline)
$frontMatter = \preg_replace('/---\R$/', '', $frontMatter);
if ($frontMatter === null) {
return new MarkdownInputWithFrontMatter($markdownContent);
}
// Parse the resulting YAML data
$data = $this->frontMatterParser->parse($frontMatter);
// Advance through any remaining newlines which separated the front matter from the Markdown text
$trailingNewlines = $cursor->match('/^\R+/');
// Calculate how many lines the Markdown is offset from the front matter by counting the number of newlines
// Don't forget to add 1 because we stripped one out when trimming the trailing delims
$lineOffset = \preg_match_all('/\R/', $frontMatter . $trailingNewlines) + 1;
return new MarkdownInputWithFrontMatter($cursor->getRemainder(), $lineOffset, $data);
}
}