David and Katherine Goodwin

Drupal Comment Spam

For the last few months, I've been suffering under the weight of spam awaiting 'approval' from me in the comment moderation queue.

On Saturday, I finally hacked the comment.module file to make Drupal reject spam which matched the following :

• Author and Subject were the same - strangely a lot of spam seems to be in the format where the author and subject fields are set to the same value.
• Body contains more than a set number of URLs - this is quite a harsh restriction I guess, but very few valid comments contain URLs anyway. I did originally have it blocking any URLS, but have since changed it to only allowing a certain number.

Spam will still have to pass through moderation from Kat or I, but so far it does seem to have stopped any crap from being posted.

The Changes

I edited comment.module and within the comment_validate function, I added the following :

  if(preg_match_all('/(http|\[url)/', $edit['comment'], $matches)) {
      if(sizeof($matches[0])>4) {
          form_set_error('comment', t("Comment contains too many URLs. (Spam protection)"));
      }
  }
  if($edit['subject'] == $edit['name']) {
      form_set_error('subject', t('Subject and author need to be different (Spam protection)'));
  }

I quite like the form_set_error function; and have been using something similar at work.

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