I am experiencing problems considering the write implementation of "Extracting cities from database" and filling data in dropDownlist. That's why I opened the blog tutorial demo and looked about Tags and Comments. Then, I saw the components folder, full of files. What is it exactly for?
The purpose for the components folder (in the protected directory) is to store classes (based on the CComponent class) that containes logic that might be shared between several controllers or other classes, where the logic can not cleanly be defined to be a view, model or controller.