109 lines
2.7 KiB
PHP
109 lines
2.7 KiB
PHP
<?php
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declare(strict_types=1);
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namespace League\HTMLToMarkdown\Converter;
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use League\HTMLToMarkdown\ElementInterface;
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class ParagraphConverter implements ConverterInterface
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{
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public function convert(ElementInterface $element): string
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{
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$value = $element->getValue();
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$markdown = '';
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$lines = \preg_split('/\r\n|\r|\n/', $value);
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\assert($lines !== false);
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foreach ($lines as $line) {
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/*
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* Some special characters need to be escaped based on the position that they appear
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* The following function will deal with those special cases.
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*/
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$markdown .= $this->escapeSpecialCharacters($line);
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$markdown .= "\n";
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}
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return \trim($markdown) !== '' ? \rtrim($markdown) . "\n\n" : '';
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}
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/**
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* @return string[]
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*/
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public function getSupportedTags(): array
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{
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return ['p'];
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}
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private function escapeSpecialCharacters(string $line): string
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{
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$line = $this->escapeFirstCharacters($line);
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$line = $this->escapeOtherCharacters($line);
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$line = $this->escapeOtherCharactersRegex($line);
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return $line;
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}
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private function escapeFirstCharacters(string $line): string
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{
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$escapable = [
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'>',
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'- ',
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'+ ',
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'--',
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'~~~',
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'---',
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'- - -',
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];
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foreach ($escapable as $i) {
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if (\strpos(\ltrim($line), $i) === 0) {
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// Found a character that must be escaped, adding a backslash before
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return '\\' . \ltrim($line);
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}
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}
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return $line;
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}
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private function escapeOtherCharacters(string $line): string
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{
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$escapable = [
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'<!--',
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];
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foreach ($escapable as $i) {
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if (($pos = \strpos($line, $i)) === false) {
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continue;
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}
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// Found an escapable character, escaping it
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$line = \substr_replace($line, '\\', $pos, 0);
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}
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return $line;
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}
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private function escapeOtherCharactersRegex(string $line): string
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{
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$regExs = [
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// Match numbers ending on ')' or '.' that are at the beginning of the line.
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// They will be escaped if immediately followed by a space or newline.
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'/^[0-9]+(?=(\)|\.)( |$))/',
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];
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foreach ($regExs as $i) {
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if (! \preg_match($i, $line, $match)) {
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continue;
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}
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// Matched an escapable character, adding a backslash on the string before the offending character
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$line = \substr_replace($line, '\\', \strlen($match[0]), 0);
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}
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return $line;
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}
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}
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