Do I need a Firefox plugin or an extension?

Question

I need to read every url that loads into the navigation bar of firefox (either by type in or by clicking a link), pass them through a filter and decide if allow the url to open or not.

I have some experience on firefox extensions but not with plugins.

Do I need to do it using extensions or plugins for this?

I currently have a BHO for IE that does this, and I get the URLs using the web browser events.

Answer 1

An extension would be just fine. For what you want to do, you need nsIObserverService, and http-on-modify-request observer.

Answer 2

You can use Adblock Plus (See the video)