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  * Using a private tag so it won't appear for visitors.
  14  */
  15 define('NO_MD_TAG', '.nomarkdown');
  16
  17 /**
  18  * Parse linklist descriptions.
  19  *
  20  * @param array $data linklist data.
  21  *
  22  * @return mixed linklist data parsed in markdown (and converted to HTML).
  23  */
  24 function hook_markdown_render_linklist($data)
  25 {
  26     foreach ($data['links'] as &$value) {
  27         if (!empty($value['tags']) && noMarkdownTag($value['tags'])) {
  28             continue;
  29         }
  30         $value['description'] = process_markdown($value['description']);
  31     }
  32
  33     return $data;
  34 }
  35
  36 /**
  37  * Parse feed linklist descriptions.
  38  *
  39  * @param array $data linklist data.
  40  *
  41  * @return mixed linklist data parsed in markdown (and converted to HTML).
  42  */
  43 function hook_markdown_render_feed($data)
  44 {
  45     foreach ($data['links'] as &$value) {
  46         if (!empty($value['tags']) && noMarkdownTag($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  * When link list is displayed, include markdown CSS.
  91  *
  92  * @param array $data includes data.
  93  *
  94  * @return mixed - includes data with markdown CSS file added.
  95  */
  96 function hook_markdown_render_includes($data)
  97 {
  98     if ($data['_PAGE_'] == Router::$PAGE_LINKLIST
  99         || $data['_PAGE_'] == Router::$PAGE_DAILY
 100         || $data['_PAGE_'] == Router::$PAGE_EDITLINK
 101     ) {
 102
 103         $data['css_files'][] = PluginManager::$PLUGINS_PATH . '/markdown/markdown.css';
 104     }
 105
 106     return $data;
 107 }
 108
 109 /**
 110  * Hook render_editlink.
 111  * Adds an help link to markdown syntax.
 112  *
 113  * @param array $data data passed to plugin
 114  *
 115  * @return array altered $data.
 116  */
 117 function hook_markdown_render_editlink($data)
 118 {
 119     // Load help HTML into a string
 120     $data['edit_link_plugin'][] = file_get_contents(PluginManager::$PLUGINS_PATH .'/markdown/help.html');
 121
 122     // Add no markdown 'meta-tag' in tag list if it was never used, for autocompletion.
 123     if (! in_array(NO_MD_TAG, $data['tags'])) {
 124         $data['tags'][NO_MD_TAG] = 0;
 125     }
 126
 127     return $data;
 128 }
 129
 130
 131 /**
 132  * Remove HTML links auto generated by Shaarli core system.
 133  * Keeps HREF attributes.
 134  *
 135  * @param string $description input description text.
 136  *
 137  * @return string $description without HTML links.
 138  */
 139 function reverse_text2clickable($description)
 140 {
 141     return preg_replace('!<a +href="([^ ]*)">[^ ]+</a>!m', '$1', $description);
 142 }
 143
 144 /**
 145  * Remove <br> tag to let markdown handle it.
 146  *
 147  * @param string $description input description text.
 148  *
 149  * @return string $description without <br> tags.
 150  */
 151 function reverse_nl2br($description)
 152 {
 153     return preg_replace('!<br */?>!im', '', $description);
 154 }
 155
 156 /**
 157  * Remove HTML spaces '&nbsp;' auto generated by Shaarli core system.
 158  *
 159  * @param string $description input description text.
 160  *
 161  * @return string $description without HTML links.
 162  */
 163 function reverse_space2nbsp($description)
 164 {
 165     return preg_replace('/(^| )&nbsp;/m', '$1 ', $description);
 166 }
 167
 168 /**
 169  * Remove dangerous HTML tags (tags, iframe, etc.).
 170  * Doesn't affect <code> content (already escaped by Parsedown).
 171  *
 172  * @param string $description input description text.
 173  *
 174  * @return string given string escaped.
 175  */
 176 function sanitize_html($description)
 177 {
 178     $escapeTags = array(
 179         'script',
 180         'style',
 181         'link',
 182         'iframe',
 183         'frameset',
 184         'frame',
 185     );
 186     foreach ($escapeTags as $tag) {
 187         $description = preg_replace_callback(
 188             '#<\s*'. $tag .'[^>]*>(.*</\s*'. $tag .'[^>]*>)?#is',
 189             function ($match) { return escape($match[0]); },
 190             $description);
 191     }
 192     $description = preg_replace(
 193         '#(<[^>]+)on[a-z]*="[^"]*"#is',
 194         '$1',
 195         $description);
 196     return $description;
 197 }
 198
 199 /**
 200  * Render shaare contents through Markdown parser.
 201  *   1. Remove HTML generated by Shaarli core.
 202  *   2. Reverse the escape function.
 203  *   3. Generate markdown descriptions.
 204  *   4. Sanitize sensible HTML tags for security.
 205  *   5. Wrap description in 'markdown' CSS class.
 206  *
 207  * @param string $description input description text.
 208  *
 209  * @return string HTML processed $description.
 210  */
 211 function process_markdown($description)
 212 {
 213     $parsedown = new Parsedown();
 214
 215     $processedDescription = $description;
 216     $processedDescription = reverse_text2clickable($processedDescription);
 217     $processedDescription = reverse_nl2br($processedDescription);
 218     $processedDescription = reverse_space2nbsp($processedDescription);
 219     $processedDescription = unescape($processedDescription);
 220     $processedDescription = $parsedown
 221         ->setMarkupEscaped(false)
 222         ->setBreaksEnabled(true)
 223         ->text($processedDescription);
 224     $processedDescription = sanitize_html($processedDescription);
 225
 226     if(!empty($processedDescription)){
 227         $processedDescription = '<div class="markdown">'. $processedDescription . '</div>';
 228     }
 229
 230     return $processedDescription;
 231 }