plugins/markdown/markdown.php

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