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             $value = stripNoMarkdownTag($value);
  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             $value = stripNoMarkdownTag($value);
  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                 $value2 = stripNoMarkdownTag($value2);
  67                 continue;
  68             }
  69             $value2['formatedDescription'] = process_markdown($value2['formatedDescription']);
  70         }
  71     }
  72
  73     return $data;
  74 }
  75
  76 /**
  77  * Check if noMarkdown is set in tags.
  78  *
  79  * @param string $tags tag list
  80  *
  81  * @return bool true if markdown should be disabled on this link.
  82  */
  83 function noMarkdownTag($tags)
  84 {
  85     return preg_match('/(^|\s)'. NO_MD_TAG .'(\s|$)/', $tags);
  86 }
  87
  88 /**
  89  * Remove the no-markdown meta tag so it won't be displayed.
  90  *
  91  * @param array $link Link data.
  92  *
  93  * @return array Updated link without no markdown tag.
  94  */
  95 function stripNoMarkdownTag($link)
  96 {
  97     if (! empty($link['taglist'])) {
  98         $offset = array_search(NO_MD_TAG, $link['taglist']);
  99         if ($offset !== false) {
 100             unset($link['taglist'][$offset]);
 101         }
 102     }
 103
 104     if (!empty($link['tags'])) {
 105         str_replace(NO_MD_TAG, '', $link['tags']);
 106     }
 107
 108     return $link;
 109 }
 110
 111 /**
 112  * When link list is displayed, include markdown CSS.
 113  *
 114  * @param array $data includes data.
 115  *
 116  * @return mixed - includes data with markdown CSS file added.
 117  */
 118 function hook_markdown_render_includes($data)
 119 {
 120     if ($data['_PAGE_'] == Router::$PAGE_LINKLIST
 121         || $data['_PAGE_'] == Router::$PAGE_DAILY
 122         || $data['_PAGE_'] == Router::$PAGE_EDITLINK
 123     ) {
 124
 125         $data['css_files'][] = PluginManager::$PLUGINS_PATH . '/markdown/markdown.css';
 126     }
 127
 128     return $data;
 129 }
 130
 131 /**
 132  * Hook render_editlink.
 133  * Adds an help link to markdown syntax.
 134  *
 135  * @param array $data data passed to plugin
 136  *
 137  * @return array altered $data.
 138  */
 139 function hook_markdown_render_editlink($data)
 140 {
 141     // Load help HTML into a string
 142     $data['edit_link_plugin'][] = file_get_contents(PluginManager::$PLUGINS_PATH .'/markdown/help.html');
 143
 144     // Add no markdown 'meta-tag' in tag list if it was never used, for autocompletion.
 145     if (! in_array(NO_MD_TAG, $data['tags'])) {
 146         $data['tags'][NO_MD_TAG] = 0;
 147     }
 148
 149     return $data;
 150 }
 151
 152
 153 /**
 154  * Remove HTML links auto generated by Shaarli core system.
 155  * Keeps HREF attributes.
 156  *
 157  * @param string $description input description text.
 158  *
 159  * @return string $description without HTML links.
 160  */
 161 function reverse_text2clickable($description)
 162 {
 163     $descriptionLines = explode(PHP_EOL, $description);
 164     $descriptionOut = '';
 165     $codeBlockOn = false;
 166     $lineCount = 0;
 167
 168     foreach ($descriptionLines as $descriptionLine) {
 169         // Detect line of code: starting with 4 spaces,
 170         // except lists which can start with +/*/- or `2.` after spaces.
 171         $codeLineOn = preg_match('/^    +(?=[^\+\*\-])(?=(?!\d\.).)/', $descriptionLine) > 0;
 172         // Detect and toggle block of code
 173         if (!$codeBlockOn) {
 174             $codeBlockOn = preg_match('/^```/', $descriptionLine) > 0;
 175         }
 176         elseif (preg_match('/^```/', $descriptionLine) > 0) {
 177             $codeBlockOn = false;
 178         }
 179
 180         $hashtagTitle = ' title="Hashtag [^"]+"';
 181         // Reverse `inline code` hashtags.
 182         $descriptionLine = preg_replace(
 183             '!(`[^`\n]*)<a href="[^ ]*"'. $hashtagTitle .'>([^<]+)</a>([^`\n]*`)!m',
 184             '$1$2$3',
 185             $descriptionLine
 186         );
 187
 188         // Reverse all links in code blocks, only non hashtag elsewhere.
 189         $hashtagFilter = (!$codeBlockOn && !$codeLineOn) ? '(?!'. $hashtagTitle .')': '(?:'. $hashtagTitle .')?';
 190         $descriptionLine = preg_replace(
 191             '#<a href="[^ ]*"'. $hashtagFilter .'>([^<]+)</a>#m',
 192             '$1',
 193             $descriptionLine
 194         );
 195
 196         $descriptionOut .= $descriptionLine;
 197         if ($lineCount++ < count($descriptionLines) - 1) {
 198             $descriptionOut .= PHP_EOL;
 199         }
 200     }
 201     return $descriptionOut;
 202 }
 203
 204 /**
 205  * Remove <br> tag to let markdown handle it.
 206  *
 207  * @param string $description input description text.
 208  *
 209  * @return string $description without <br> tags.
 210  */
 211 function reverse_nl2br($description)
 212 {
 213     return preg_replace('!<br */?>!im', '', $description);
 214 }
 215
 216 /**
 217  * Remove HTML spaces '&nbsp;' auto generated by Shaarli core system.
 218  *
 219  * @param string $description input description text.
 220  *
 221  * @return string $description without HTML links.
 222  */
 223 function reverse_space2nbsp($description)
 224 {
 225     return preg_replace('/(^| )&nbsp;/m', '$1 ', $description);
 226 }
 227
 228 /**
 229  * Remove dangerous HTML tags (tags, iframe, etc.).
 230  * Doesn't affect <code> content (already escaped by Parsedown).
 231  *
 232  * @param string $description input description text.
 233  *
 234  * @return string given string escaped.
 235  */
 236 function sanitize_html($description)
 237 {
 238     $escapeTags = array(
 239         'script',
 240         'style',
 241         'link',
 242         'iframe',
 243         'frameset',
 244         'frame',
 245     );
 246     foreach ($escapeTags as $tag) {
 247         $description = preg_replace_callback(
 248             '#<\s*'. $tag .'[^>]*>(.*</\s*'. $tag .'[^>]*>)?#is',
 249             function ($match) { return escape($match[0]); },
 250             $description);
 251     }
 252     $description = preg_replace(
 253         '#(<[^>]+)on[a-z]*="[^"]*"#is',
 254         '$1',
 255         $description);
 256     return $description;
 257 }
 258
 259 /**
 260  * Render shaare contents through Markdown parser.
 261  *   1. Remove HTML generated by Shaarli core.
 262  *   2. Reverse the escape function.
 263  *   3. Generate markdown descriptions.
 264  *   4. Sanitize sensible HTML tags for security.
 265  *   5. Wrap description in 'markdown' CSS class.
 266  *
 267  * @param string $description input description text.
 268  *
 269  * @return string HTML processed $description.
 270  */
 271 function process_markdown($description)
 272 {
 273     $parsedown = new Parsedown();
 274
 275     $processedDescription = $description;
 276     $processedDescription = reverse_nl2br($processedDescription);
 277     $processedDescription = reverse_space2nbsp($processedDescription);
 278     $processedDescription = reverse_text2clickable($processedDescription);
 279     $processedDescription = unescape($processedDescription);
 280     $processedDescription = $parsedown
 281         ->setMarkupEscaped(false)
 282         ->setBreaksEnabled(true)
 283         ->text($processedDescription);
 284     $processedDescription = sanitize_html($processedDescription);
 285
 286     if(!empty($processedDescription)){
 287         $processedDescription = '<div class="markdown">'. $processedDescription . '</div>';
 288     }
 289
 290     return $processedDescription;
 291 }