thephpleague / html-to-markdown

src/Converter/ParagraphConverter.php

<?php

namespace League\HTMLToMarkdown\Converter;

use League\HTMLToMarkdown\ElementInterface;

class ParagraphConverter implements ConverterInterface
{
    /**
     * @param ElementInterface $element
     *
     * @return string
     */
    public function convert(ElementInterface $element)
    {
        $value = $element->getValue();

        $markdown = '';

        $lines = preg_split('/\r\n|\r|\n/', $value);
        foreach ($lines as $line) {
            /*
             * Some special characters need to be escaped based on the position that they appear
             * The following function will deal with those special cases.
             */
            $markdown .= $this->escapeSpecialCharacters($line);
            $markdown .= "\n";
        }

        return trim($markdown) !== '' ? rtrim($markdown) . "\n\n" : '';
    }

    /**
     * @return string[]
     */
    public function getSupportedTags()
    {
        return array('p');
    }

    /**
     * @param string $line
     *
     * @return string
     */
    private function escapeSpecialCharacters($line)
    {
        $line = $this->escapeHeaderlikeCharacters($line);
        $line = $this->escapeBlockquotelikeCharacters($line);
        $line = $this->escapeOrderedListlikeCharacters($line);
        $line = $this->escapeListlikeCharacters($line);

        return $line;
    }

    /**
     * @param string $line
     *
     * @return string
     */
    private function escapeBlockquotelikeCharacters($line)

This method seems to be duplicated in your project.

    {
        if (strpos(ltrim($line), '>') === 0) {
            // Found a > char, escaping it
            return '\\' . ltrim($line);
        } else {
            return $line;
        }
    }

    /**
     * @param string $line
     *
     * @return string
     */
    private function escapeHeaderlikeCharacters($line)

This method seems to be duplicated in your project.

    {
        if (strpos(ltrim($line), '--') === 0) {
            // Found a -- structure, escaping it
            return '\\' . ltrim($line);
        } else {
            return $line;
        }
    }

    /**
     * @param string $line
     *
     * @return string
     */
    private function escapeOrderedListlikeCharacters($line)
    {
        // This regex will match numbers ending on ')' or '.' that are at the beginning of the line.
        if (preg_match('/^[0-9]+(?=\)|\.)/', $line, $match)) {
            // Found an Ordered list like character, escaping it
            return substr_replace($line, '\\', strlen($match[0]), 0);
        } else {
            return $line;
        }
    }

    /**
     * @param string $line
     *
     * @return string
     */
    private function escapeListlikeCharacters($line)
    {
        if (strpos(ltrim($line), '- ') === 0 || strpos(ltrim($line), '+ ') === 0) {
            // Found an list like character, escaping it
            return '\\' . ltrim($line);
        } else {
            return $line;
        }
    }
}