Generally we need to show one or more fields from a model that is related to another model used in CGridView.
For our case we will use two related models, which explain how to use model "A" fields in a CGridView that used model "B".
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.
Clearing CGridView filters and sort orders from the web pages, is usefull for the end user. Yii does not seem to propose a standard method. Furthermore, this is especially usefull when filters are "remembered" in the user's session.