More or less I use auto-complete field for a form. CJuiAutoComplete is a yii widget for this purposes.
The common use case is to make an ajax request and retrieve a list from the database. So in this case you have to write a controller action to return you a json encoded list.
What if I had a generic action to do this work for me?
Usually when we use AutoComplete in a project, We need to show "title" or "name" in the list, while when the form is posted, we need some sort of integer ID referring to the selected value. Out of the Box, CJuiAutoComplete widget doesn't provides different display text and post values.