Automatically Escape HTML Entities of Code Fragments in Comments

Dec 26, 2009 WordPress 9 comments

Update: Ryan has made this into a plugin — Code Comments.

Add this to your theme’s functions.php to allow readers post fragments of code in their comments (wrapped in <code>...</code>) which are automatically encoded (think of < and <)

add_filter('pre_comment_content', 'encode_code_in_comment');

function encode_code_in_comment($source) {
  $encoded = preg_replace_callback('/<code>(.*?)<\/code>/ims',
  create_function(
    '$matches',
    '$matches[1] = preg_replace(
        array("/^[\r|\n]+/i", "/[\r|\n]+$/i"), "",
        $matches[1]);
      return "<code>" . htmlentities($matches[1]) . "</code>";'
  ),
  $source);

  if ($encoded)
    return $encoded;
  else
    return $source;
}

Worth noting:

• Everything wrapped in <code>...</code> is encoded.
• Line breaks after opening <code> and before closing </code> are removed in order to avoid unnecessary <br /> tags.

# 9 Comments