thephpleague / html-to-markdown

<?php

declare(strict_types=1);

namespace League\HTMLToMarkdown\Converter;

use League\HTMLToMarkdown\ElementInterface;

class TextConverter implements ConverterInterface

{

    public function convert(ElementInterface $element): string

    {

        $markdown = $element->getValue();

        // Remove leftover \n at the beginning of the line

        $markdown = \ltrim($markdown, "\n");

        // Replace sequences of invisible characters with spaces

        $markdown = \preg_replace('~\s+~u', ' ', $markdown);

        \assert(\is_string($markdown));

        // Escape the following characters: '*', '_', '[', ']' and '\'

        if (($parent = $element->getParent()) && $parent->getTagName() !== 'div') {

            $markdown = \preg_replace('~([*_\\[\\]\\\\])~u', '\\\\$1', $markdown);

            \assert(\is_string($markdown));

        }

        $markdown = \preg_replace('~^#~u', '\\\\#', $markdown);

        \assert(\is_string($markdown));

        if ($markdown === ' ') {

            $next = $element->getNext();

            if (! $next || $next->isBlock()) {

                $markdown = '';

            }

        }

        return \htmlspecialchars($markdown, ENT_NOQUOTES, 'UTF-8');

    }

    /**

     * @return string[]

     */

    public function getSupportedTags(): array

    {

        return ['#text'];

    }

}