For this recipe, we will reuse the my_library add-on module from the previous recipe. In the previous recipe, we added a button in the <header> tag. We will hide that whole header from a few users by adding a groups attribute to it.

Add the model, the views, and the menus for the book.category model. We will hide the category menus from a user. Refer to Chapter 5, Application Models, to see how to add model views and menus.