143 lines
3.9 KiB
PHP
143 lines
3.9 KiB
PHP
<?php
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declare(strict_types=1);
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/*
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* This file is part of the league/commonmark package.
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*
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* (c) Colin O'Dell <colinodell@gmail.com>
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*
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* Original code based on the CommonMark JS reference parser (https://bitly.com/commonmark-js)
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* - (c) John MacFarlane
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*
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* For the full copyright and license information, please view the LICENSE
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* file that was distributed with this source code.
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*/
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namespace League\CommonMark\Util;
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use League\CommonMark\Parser\Cursor;
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/**
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* @psalm-immutable
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*/
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final class LinkParserHelper
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{
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/**
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* Attempt to parse link destination
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*
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* @return string|null The string, or null if no match
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*/
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public static function parseLinkDestination(Cursor $cursor): ?string
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{
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if ($res = $cursor->match(RegexHelper::REGEX_LINK_DESTINATION_BRACES)) {
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// Chop off surrounding <..>:
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return UrlEncoder::unescapeAndEncode(
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RegexHelper::unescape(\substr($res, 1, -1))
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);
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}
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if ($cursor->getCurrentCharacter() === '<') {
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return null;
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}
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$destination = self::manuallyParseLinkDestination($cursor);
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if ($destination === null) {
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return null;
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}
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return UrlEncoder::unescapeAndEncode(
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RegexHelper::unescape($destination)
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);
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}
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public static function parseLinkLabel(Cursor $cursor): int
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{
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$match = $cursor->match('/^\[(?:[^\\\\\[\]]|\\\\.){0,1000}\]/');
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if ($match === null) {
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return 0;
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}
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$length = \mb_strlen($match, 'UTF-8');
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if ($length > 1001) {
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return 0;
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}
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return $length;
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}
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public static function parsePartialLinkLabel(Cursor $cursor): ?string
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{
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return $cursor->match('/^(?:[^\\\\\[\]]+|\\\\.?)*/');
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}
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/**
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* Attempt to parse link title (sans quotes)
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*
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* @return string|null The string, or null if no match
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*/
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public static function parseLinkTitle(Cursor $cursor): ?string
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{
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if ($title = $cursor->match('/' . RegexHelper::PARTIAL_LINK_TITLE . '/')) {
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// Chop off quotes from title and unescape
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return RegexHelper::unescape(\substr($title, 1, -1));
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}
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return null;
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}
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public static function parsePartialLinkTitle(Cursor $cursor, string $endDelimiter): ?string
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{
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$endDelimiter = \preg_quote($endDelimiter, '/');
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$regex = \sprintf('/(%s|[^%s\x00])*(?:%s)?/', RegexHelper::PARTIAL_ESCAPED_CHAR, $endDelimiter, $endDelimiter);
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if (($partialTitle = $cursor->match($regex)) === null) {
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return null;
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}
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return RegexHelper::unescape($partialTitle);
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}
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private static function manuallyParseLinkDestination(Cursor $cursor): ?string
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{
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$oldPosition = $cursor->getPosition();
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$oldState = $cursor->saveState();
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$openParens = 0;
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while (($c = $cursor->getCurrentCharacter()) !== null) {
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if ($c === '\\' && ($peek = $cursor->peek()) !== null && RegexHelper::isEscapable($peek)) {
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$cursor->advanceBy(2);
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} elseif ($c === '(') {
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$cursor->advanceBy(1);
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$openParens++;
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} elseif ($c === ')') {
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if ($openParens < 1) {
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break;
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}
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$cursor->advanceBy(1);
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$openParens--;
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} elseif (\preg_match(RegexHelper::REGEX_WHITESPACE_CHAR, $c)) {
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break;
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} else {
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$cursor->advanceBy(1);
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}
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}
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if ($openParens !== 0) {
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return null;
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}
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if ($cursor->getPosition() === $oldPosition && (! isset($c) || $c !== ')')) {
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return null;
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}
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$newPos = $cursor->getPosition();
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$cursor->restoreState($oldState);
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$cursor->advanceBy($newPos - $cursor->getPosition());
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return $cursor->getPreviousText();
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}
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}
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