As I'm new to the framework (2 weeks) - I tried to build a functionallity I already use a lot in my old framework (PRADO). This means combining a GridView with a form. And this in one page, what allows you to select a record from the grid and view the values in the same page without jumping to a new page.
Sometimes the active form we wish to use to edit/add a new element on our database is too small and we believe that is much better to use an AJAX'ed dialog/slide form rather than reloading the page to just display one or two fields.
Changing the way a CGridView is rendered from the configuration file, or through behaviors specified at the moment it is used, is handy to extend a CGridView without creating tons of different classes for it.
I am surprised that this is not in the default implementation, so I made my default CGridView implementation.