As you've seen in
Chapter 8, Backend Views, there's a plethora of widgets that display your data in a certain way. To demonstrate how to create your own widget, we'll write one that lets the user choose a
many2one reference from a predefined selection of values in the form of a list of buttons. The result looks somewhat similar to the
many2many_checkboxes widget, but with buttons instead of checkboxes.
You'll need to create an empty addon that depends on the
web module; we call it