Chapter 14: Interact With Other Modules

In the previous chapter, we used inheritance to modify the behavior of a module. In our real estate scenario, we would like to go a step further and be able to generate invoices for our customers. Odoo provides an Invoicing module, so it would be neat to create an invoice directly from our real estate module, i.e. once a property is set to ‘Sold’, an invoice is created in the Invoicing application.

Concrete Example: Account Move

 Note

Goal: at the end of this section:

• A new module estate_account should be created

• When a property is sold, an invoice should be issued for the buyer

Any time we interact with another module, we need to keep in mind the modularity. If we intend to sell our application to real estate agencies, some may want the invoicing feature but others may not want it.

Link Module

The common approach for such use cases is to create a ‘link’ module. In our case, the module would depend on estate and account and would include the invoice creation logic of the estate property. This way the real estate and the accounting modules can be installed independently. When both are installed, the link module provides the new feature.

When the estate_account module appears in the list, go ahead and install it! You’ll notice that the Invoicing application is installed as well. This is expected since your module depends on it. If you uninstall the Invoicing application, your module will be uninstalled as well.

Invoice Creation

It’s now time to generate the invoice. We want to add functionality to the estate.property model, i.e. we want to add some extra logic for when a property is sold. Does that sound familiar? If not, it’s a good idea to go back to the previous chapter since you might have missed something ;-)

As a first step, we need to extend the action called when pressing the ‘Sold’ button on a property. To do so, we need to create a model inheritance in the estate_account module for the estate.property model. For now, the overridden action will simply return the super call. Maybe an example will make things clearer:

from odoo import models

class InheritedModel(models.Model):
    _inherit = "inherited.model"

    def inherited_action(self):
        return super().inherited_action()

A practical example can be found here.

Is it working? If not, maybe check that all Python files are correctly imported.

If the override is working, we can move forward and create the invoice. Unfortunately, there is no easy way to know how to create any given object in Odoo. Most of the time, it is necessary to have a look at its model to find the required fields and provide appropriate values.

A good way to learn is to look at how other modules already do what you want to do. For example, one of the basic flows of Sales is the creation of an invoice from a sales order. This looks like a good starting point since it does exactly what we want to do. Take some time to read and understand the _create_invoices method. When you are done crying because this simple task looks awfully complex, we can move forward in the tutorial.

To create an invoice, we need the following information:

• a partner_id: the customer

• a move_type: it has several possible values

• a journal_id: the accounting journal

This is enough to create an empty invoice.

When a property is set to ‘Sold’, you should now have a new customer invoice created in Invoicing / Customers / Invoices.

Obviously we don’t have any invoice lines so far. To create an invoice line, we need the following information:

• name: a description of the line

• quantity

• price_unit

Moreover, an invoice line needs to be linked to an invoice. The easiest and most efficient way to link a line to an invoice is to include all lines at invoice creation. To do this, the invoice_line_ids field is included in the account.move creation, which is a One2many. One2many and Many2many use special ‘commands’ which have been made human readable with the Command namespace. This namespace represents a triplet command to execute on a set of records. The triplet was originally the only option to do these commands, but it is now standard to use the namespace instead. The format is to place them in a list which is executed sequentially. Here is a simple example to include a One2many field line_ids at creation of a test.model:

from odoo import Command

def inherited_action(self):
    self.env["test.model"].create(
        {
            "name": "Test",
            "line_ids": [
                Command.create({
                    "field_1": "value_1",
                    "field_2": "value_2",
                })
            ],
        }
    )
    return super().inherited_action()

This chapter might be one of the most difficult that has been covered so far, but it is the closest to what Odoo development will be in practice. In the next chapter, we will introduce the templating mechanism used in Odoo.