BookStack Code Mirror - bookstack/blob - app/Entities/Tools/Markdown/HtmlToMarkdown.php

   1 <?php namespace BookStack\Entities\Tools\Markdown;
   2
   3 use League\HTMLToMarkdown\Converter\BlockquoteConverter;
   4 use League\HTMLToMarkdown\Converter\CodeConverter;
   5 use League\HTMLToMarkdown\Converter\CommentConverter;
   6 use League\HTMLToMarkdown\Converter\DivConverter;
   7 use League\HTMLToMarkdown\Converter\EmphasisConverter;
   8 use League\HTMLToMarkdown\Converter\HardBreakConverter;
   9 use League\HTMLToMarkdown\Converter\HeaderConverter;
  10 use League\HTMLToMarkdown\Converter\HorizontalRuleConverter;
  11 use League\HTMLToMarkdown\Converter\ImageConverter;
  12 use League\HTMLToMarkdown\Converter\LinkConverter;
  13 use League\HTMLToMarkdown\Converter\ListBlockConverter;
  14 use League\HTMLToMarkdown\Converter\ListItemConverter;
  15 use League\HTMLToMarkdown\Converter\PreformattedConverter;
  16 use League\HTMLToMarkdown\Converter\TextConverter;
  17 use League\HTMLToMarkdown\Environment;
  18 use League\HTMLToMarkdown\HtmlConverter;
  19
  20 class HtmlToMarkdown
  21 {
  22     protected $html;
  23
  24     public function __construct(string $html)
  25     {
  26         $this->html = $html;
  27     }
  28
  29     /**
  30      * Run the conversion
  31      */
  32     public function convert(): string
  33     {
  34         $converter = new HtmlConverter($this->getConverterEnvironment());
  35         $html = $this->prepareHtml($this->html);
  36         return $converter->convert($html);
  37     }
  38
  39     /**
  40      * Run any pre-processing to the HTML to clean it up manually before conversion.
  41      */
  42     protected function prepareHtml(string $html): string
  43     {
  44         // Carriage returns can cause whitespace issues in output
  45         $html = str_replace("\r\n", "\n", $html);
  46         // Attributes on the pre tag can cause issues with conversion
  47         return preg_replace('/<pre .*?>/', '<pre>', $html);
  48     }
  49
  50     /**
  51      * Get the HTML to Markdown customized environment.
  52      * Extends the default provided environment with some BookStack specific tweaks.
  53      */
  54     protected function getConverterEnvironment(): Environment
  55     {
  56         $environment = new Environment(['header_style' => 'atx']);
  57
  58         $environment->addConverter(new BlockquoteConverter());
  59         $environment->addConverter(new CodeConverter());
  60         $environment->addConverter(new CommentConverter());
  61         $environment->addConverter(new DivConverter());
  62         $environment->addConverter(new EmphasisConverter());
  63         $environment->addConverter(new HardBreakConverter());
  64         $environment->addConverter(new HeaderConverter());
  65         $environment->addConverter(new HorizontalRuleConverter());
  66         $environment->addConverter(new ImageConverter());
  67         $environment->addConverter(new LinkConverter());
  68         $environment->addConverter(new ListBlockConverter());
  69         $environment->addConverter(new ListItemConverter());
  70         $environment->addConverter(new CustomParagraphConverter());
  71         $environment->addConverter(new PreformattedConverter());
  72         $environment->addConverter(new TextConverter());
  73
  74         return $environment;
  75     }
  76 }