Checklist for high quality websites part 2

Jan 28, 2009

The second part of the checklist is about server side code and security [More]

Has privacy limited our possibilities?

Dec 12, 2007

Big Web 2.0 API's are restricting the amount of information for developers [More]

Create your own spam filter extensions

Dec 12, 2007

My last post about comment spam fighting resulted in a lot of e-mails from readers asking how to create their own spam fighting logic in BlogEngine.NET 1.3. So I decided to show a simple extension that listens for certain bad words and filters on those. If a comment contains one of the predefined words it is considered spam. The extension [Extension("Filters comments containing bad words", "1.0", "Mads Kristensen")] public class BadWordFilter { // Constructor public BadWordFilter() { // Add the event handler for the CommentAdded event Post.AddingComment += new EventHandler<CancelEventArgs>(Post_AddingComment); } // The collection of bad words private static readonly StringCollection BAD_WORDS = AddBadWords(); // Add bad words to the collection private static StringCollection AddBadWords() { StringCollection col = new StringCollection(); col.Add("VIAGRA"); col.Add("CASINO"); col.Add("MORTAGE"); return col; } // Handle the AddingComment event private void Post_AddingComment(object sender, CancelEventArgs e) { Comment comment = (Comment)sender; string body = comment.Content.ToUpperInvariant(); // Search for bad words in the comment body foreach (string word in BAD_WORDS) { if (body.Contains(word)) { // Cancel the comment and raise the SpamAttack event e.Cancel = true; Comment.OnSpamAttack(); break; } } } } The problem with an extension that filters based on bad words is that if you have a blog about medicine then Viagra probably isn’t a bad word. Therefore this type of spam fighting is left out of the release, but is offered as a separate download where you are able to define your own bad words. Download BadWordFilter.zip (743 bytes)