Extending the business logic defined in a Model

When defining a model that extends another model, it is often necessary to customize the behavior of some methods defined on the original model. This is a very easy task in Odoo, and one of the most powerful features of the underlying framework.

We will demonstrate this by extending a method that creates records to add a new field in the created records.

Getting ready

If you want to follow the recipe, ensure that you have the my_module addon from Chapter 4, Creating Odoo addon Modules, with the loan wizard defined in the Writing a wizard to guide the user recipe from Chapter 9,Advanced Server-Side Development Techniques.

Create a new addon module called library_loan_return_date that depends on my_module. In this module, extend the library.book.loan model, as follows:

class LibraryBookLoan(models.Model): 
    _inherit = 'library.book.loan' 
    expected_return_date = fields.Date('Due for', required=True) 

Extend the library.member model, as follows...