Extending the business logic defined in a model

It is a very common practice in Odoo to divide application features into different modules. By doing so, you can simply enable/disable features by installing/uninstalling the application. And when you add new features to the existing app, it then becomes necessary to customize the behavior of some methods that were defined in the original app. Sometimes, you also want to add new fields to an existing model. This is a very easy task in Odoo, and one of the most powerful features of the underlying framework.

In this recipe, we will see how you can extend the business logic of one method from the method in another module. We will also add new fields to an existing module from the new module.

Getting ready

For this recipe, we will continue to use the my_library module from the last recipe. Make sure that you have the library.book.category model in the my_library module.

For this recipe, we will create a new module called my_library_return...