plugins/markdown/markdown.php

   1 <?php
   2
   3 /**
   4  * Plugin Markdown.
   5  *
   6  * Shaare's descriptions are parsed with Markdown.
   7  */
   8
   9 require_once 'Parsedown.php';
  10
  11 /*
  12  * If this tag is used on a shaare, the description won't be processed by Parsedown.
  13  */
  14 define('NO_MD_TAG', 'nomarkdown');
  15
  16 /**
  17  * Parse linklist descriptions.
  18  *
  19  * @param array $data linklist data.
  20  *
  21  * @return mixed linklist data parsed in markdown (and converted to HTML).
  22  */
  23 function hook_markdown_render_linklist($data)
  24 {
  25     foreach ($data['links'] as &$value) {
  26         if (!empty($value['tags']) && noMarkdownTag($value['tags'])) {
  27             $value['taglist'] = stripNoMarkdownTag($value['taglist']);
  28             continue;
  29         }
  30         $value['description'] = process_markdown($value['description']);
  31     }
  32     return $data;
  33 }
  34
  35 /**
  36  * Parse feed linklist descriptions.
  37  *
  38  * @param array $data linklist data.
  39  *
  40  * @return mixed linklist data parsed in markdown (and converted to HTML).
  41  */
  42 function hook_markdown_render_feed($data)
  43 {
  44     foreach ($data['links'] as &$value) {
  45         if (!empty($value['tags']) && noMarkdownTag($value['tags'])) {
  46             $value['tags'] = stripNoMarkdownTag($value['tags']);
  47             continue;
  48         }
  49         $value['description'] = process_markdown($value['description']);
  50     }
  51
  52     return $data;
  53 }
  54
  55 /**
  56  * Parse daily descriptions.
  57  *
  58  * @param array $data daily data.
  59  *
  60  * @return mixed daily data parsed in markdown (and converted to HTML).
  61  */
  62 function hook_markdown_render_daily($data)
  63 {
  64     // Manipulate columns data
  65     foreach ($data['cols'] as &$value) {
  66         foreach ($value as &$value2) {
  67             if (!empty($value2['tags']) && noMarkdownTag($value2['tags'])) {
  68                 continue;
  69             }
  70             $value2['formatedDescription'] = process_markdown($value2['formatedDescription']);
  71         }
  72     }
  73
  74     return $data;
  75 }
  76
  77 /**
  78  * Check if noMarkdown is set in tags.
  79  *
  80  * @param string $tags tag list
  81  *
  82  * @return bool true if markdown should be disabled on this link.
  83  */
  84 function noMarkdownTag($tags)
  85 {
  86     return strpos($tags, NO_MD_TAG) !== false;
  87 }
  88
  89 /**
  90  * Remove the no-markdown meta tag so it won't be displayed.
  91  *
  92  * @param string $tags Tag list.
  93  *
  94  * @return string tag list without no markdown tag.
  95  */
  96 function stripNoMarkdownTag($tags)
  97 {
  98     unset($tags[array_search(NO_MD_TAG, $tags)]);
  99     return array_values($tags);
 100 }
 101
 102 /**
 103  * When link list is displayed, include markdown CSS.
 104  *
 105  * @param array $data includes data.
 106  *
 107  * @return mixed - includes data with markdown CSS file added.
 108  */
 109 function hook_markdown_render_includes($data)
 110 {
 111     if ($data['_PAGE_'] == Router::$PAGE_LINKLIST
 112         || $data['_PAGE_'] == Router::$PAGE_DAILY
 113         || $data['_PAGE_'] == Router::$PAGE_EDITLINK
 114     ) {
 115
 116         $data['css_files'][] = PluginManager::$PLUGINS_PATH . '/markdown/markdown.css';
 117     }
 118
 119     return $data;
 120 }
 121
 122 /**
 123  * Hook render_editlink.
 124  * Adds an help link to markdown syntax.
 125  *
 126  * @param array $data data passed to plugin
 127  *
 128  * @return array altered $data.
 129  */
 130 function hook_markdown_render_editlink($data)
 131 {
 132     // Load help HTML into a string
 133     $data['edit_link_plugin'][] = file_get_contents(PluginManager::$PLUGINS_PATH .'/markdown/help.html');
 134
 135     // Add no markdown 'meta-tag' in tag list if it was never used, for autocompletion.
 136     if (! in_array(NO_MD_TAG, $data['tags'])) {
 137         $data['tags'][NO_MD_TAG] = 0;
 138     }
 139
 140     return $data;
 141 }
 142
 143
 144 /**
 145  * Remove HTML links auto generated by Shaarli core system.
 146  * Keeps HREF attributes.
 147  *
 148  * @param string $description input description text.
 149  *
 150  * @return string $description without HTML links.
 151  */
 152 function reverse_text2clickable($description)
 153 {
 154     $descriptionLines = explode(PHP_EOL, $description);
 155     $descriptionOut = '';
 156     $codeBlockOn = false;
 157     $lineCount = 0;
 158
 159     foreach ($descriptionLines as $descriptionLine) {
 160         // Detect line of code
 161         $codeLineOn = preg_match('/^    /', $descriptionLine) > 0;
 162         // Detect and toggle block of code
 163         if (!$codeBlockOn) {
 164             $codeBlockOn = preg_match('/^```/', $descriptionLine) > 0;
 165         }
 166         elseif (preg_match('/^```/', $descriptionLine) > 0) {
 167             $codeBlockOn = false;
 168         }
 169
 170         $hashtagTitle = ' title="Hashtag [^"]+"';
 171         // Reverse `inline code` hashtags.
 172         $descriptionLine = preg_replace(
 173             '!(`[^`\n]*)<a href="[^ ]*"'. $hashtagTitle .'>([^<]+)</a>([^`\n]*`)!m',
 174             '$1$2$3',
 175             $descriptionLine
 176         );
 177
 178         // Reverse hashtag links if we're in a code block.
 179         $hashtagFilter = ($codeBlockOn || $codeLineOn) ? $hashtagTitle : '';
 180         $descriptionLine = preg_replace(
 181             '!<a href="[^ ]*"'. $hashtagFilter .'>([^<]+)</a>!m',
 182             '$1',
 183             $descriptionLine
 184         );
 185
 186         $descriptionOut .= $descriptionLine;
 187         if ($lineCount++ < count($descriptionLines) - 1) {
 188             $descriptionOut .= PHP_EOL;
 189         }
 190     }
 191     return $descriptionOut;
 192 }
 193
 194 /**
 195  * Remove <br> tag to let markdown handle it.
 196  *
 197  * @param string $description input description text.
 198  *
 199  * @return string $description without <br> tags.
 200  */
 201 function reverse_nl2br($description)
 202 {
 203     return preg_replace('!<br */?>!im', '', $description);
 204 }
 205
 206 /**
 207  * Remove HTML spaces '&nbsp;' auto generated by Shaarli core system.
 208  *
 209  * @param string $description input description text.
 210  *
 211  * @return string $description without HTML links.
 212  */
 213 function reverse_space2nbsp($description)
 214 {
 215     return preg_replace('/(^| )&nbsp;/m', '$1 ', $description);
 216 }
 217
 218 /**
 219  * Remove dangerous HTML tags (tags, iframe, etc.).
 220  * Doesn't affect <code> content (already escaped by Parsedown).
 221  *
 222  * @param string $description input description text.
 223  *
 224  * @return string given string escaped.
 225  */
 226 function sanitize_html($description)
 227 {
 228     $escapeTags = array(
 229         'script',
 230         'style',
 231         'link',
 232         'iframe',
 233         'frameset',
 234         'frame',
 235     );
 236     foreach ($escapeTags as $tag) {
 237         $description = preg_replace_callback(
 238             '#<\s*'. $tag .'[^>]*>(.*</\s*'. $tag .'[^>]*>)?#is',
 239             function ($match) { return escape($match[0]); },
 240             $description);
 241     }
 242     $description = preg_replace(
 243         '#(<[^>]+)on[a-z]*="[^"]*"#is',
 244         '$1',
 245         $description);
 246     return $description;
 247 }
 248
 249 /**
 250  * Render shaare contents through Markdown parser.
 251  *   1. Remove HTML generated by Shaarli core.
 252  *   2. Reverse the escape function.
 253  *   3. Generate markdown descriptions.
 254  *   4. Sanitize sensible HTML tags for security.
 255  *   5. Wrap description in 'markdown' CSS class.
 256  *
 257  * @param string $description input description text.
 258  *
 259  * @return string HTML processed $description.
 260  */
 261 function process_markdown($description)
 262 {
 263     $parsedown = new Parsedown();
 264
 265     $processedDescription = $description;
 266     $processedDescription = reverse_nl2br($processedDescription);
 267     $processedDescription = reverse_space2nbsp($processedDescription);
 268     $processedDescription = reverse_text2clickable($processedDescription);
 269     $processedDescription = unescape($processedDescription);
 270     $processedDescription = $parsedown
 271         ->setMarkupEscaped(false)
 272         ->setBreaksEnabled(true)
 273         ->text($processedDescription);
 274     $processedDescription = sanitize_html($processedDescription);
 275
 276     if(!empty($processedDescription)){
 277         $processedDescription = '<div class="markdown">'. $processedDescription . '</div>';
 278     }
 279
 280     return $processedDescription;
 281 }