How to write a module in Odoo

Odoo is a powerful open-source ERP system that allows developers to create custom modules to extend its functionality. In this tutorial, we will guide you through the process of creating a custom module in Odoo, including the necessary files and structure.
We will create a simple module that adds a new model to Odoo. This module will be named my_module and will contain a model called my_model with a few fields.

Prerequisites

Before we start, make sure you have the following prerequisites installed on your system:

• Odoo (version 14 or later)
• Python 3.6 or later
• PostgreSQL
• Basic knowledge of Python and Odoo development

Step 1: Create the Module Directory Structure

First, we need to create the directory structure for our module. Navigate to the Odoo addons directory and create a new folder for your module:

cd /path/to/odoo/addons
mkdir my_module
cd my_module

Now, create the following directory structure inside my_module:

mkdir -p models views security data

This structure will hold our Python models, XML views, security rules, and data files.

Step 2: Create the Manifest File

The manifest file is a Python file named __manifest__.py that contains metadata about your module. Create this file in the my_module directory:

touch __manifest__.py

Open the __manifest__.py file and add the following content:

{
    'name': 'My Module',
    'version': '1.0',
    'category': 'Custom',
    'summary': 'A simple custom module for Odoo',
    'description': """
        This module adds a new model to Odoo.
    """,
    'author': 'Your Name',
    'website': 'https://yourwebsite.com',
    'depends': ['base'],
    'data': [
        'security/ir.model.access.csv',
        'views/my_model_views.xml',
        'data/my_model_data.xml',
    ],
    'installable': True,
    'application': True,
}

This file contains information about the module, such as its name, version, dependencies, and data files to load. Make sure to replace Your Name and https://yourwebsite.com with your actual name and website.

Step 3: Create the Model

Next, we will create a new model in Odoo. Create a new Python file named my_model.py inside the models directory:

touch models/my_model.py

Open the my_model.py file and add the following content:

from odoo import models, fields, api
from odoo.exceptions import ValidationError

class MyModel(models.Model):
    _name = 'my.model'
    _description = 'My Model'

    name = fields.Char(string='Name', required=True)
    description = fields.Text(string='Description')
    date_created = fields.Datetime(string='Date Created', default=fields.Datetime.now)
    active = fields.Boolean(string='Active', default=True)

    @api.constrains('name')
    def _check_name(self):
        for record in self:
            if not record.name:
                raise ValidationError("Name cannot be empty.")

This code defines a new model called my.model with four fields: name, description, date_created, and active. The @api.constrains decorator is used to enforce a constraint on the name field, ensuring it cannot be empty.

Step 4: Create the Views

Next, we will create the XML views for our model. Create a new XML file named my_model_views.xml inside the views directory:

touch views/my_model_views.xml

Open the my_model_views.xml file and add the following content:

<?xml version="1.0" encoding="UTF-8"?>
<odoo>
    <data>
    <record id="view_my_model_tree" model="ir.ui.view">
        <field name="name">my.model.tree</field>
        <field name="model">my.model</field>
        <field name="arch" type="xml">
            <tree string="My Model">
                <field name="name"/>
                <field name="description"/>
                <field name="date_created"/>
                <field name="active"/>
            </tree>
        </field>
    </record>

    <record id="view_my_model_form" model="ir.ui.view">
        <field name="name">my.model.form</field>
        <field name="model">my.model</field>
        <field name="arch" type="xml">
            <form string="My Model">
                <sheet>
                    <group>
                        <group>
                            <field name="name"/>
                            <field name="description"/>
                        </group>
                        <group>
                            <field name="date_created" readonly="1"/>
                            <field name="active"/>
                        </group>
                    </group>
                </sheet>
            </form>
        </field>
    </record>

    <record id="action_my_model" model="ir.actions.act_window">
        <field name="name">My Model</field>
        <field name="res_model">my.model</field>
        <field name="view_mode">tree,form</field>
    </record>

    <menuitem id="menu_my_model" name="My Model" action="action_my_model" parent="base.menu_custom"/>
    </data>
</odoo>

This XML file defines the tree and form views for our model, as well as an action to open the model and a menu item to access it. The parent attribute in the menuitem tag specifies the parent menu under which this menu item will be displayed. You can change base.menu_custom to any existing menu ID in your Odoo instance.

Step 5: Create Security Rules

To allow users to access our model, we need to create security rules. Create a new CSV file named ir.model.access.csv inside the security directory:

touch security/ir.model.access.csv

Open the ir.model.access.csv file and add the following content:

id,name,model_id:id,group_id:id,perm_read,perm_write,perm_create,perm_unlink
access_my_model,access_my_model,model_my_model,,1,1,1,1

This CSV file defines access rights for our model. The perm_read, perm_write, perm_create, and perm_unlink columns specify the permissions for reading, writing, creating, and deleting records, respectively. In this case, we are granting all permissions to the model.

Step 6: Create Sample Data (Optional)

If you want to create some sample data for your model, you can create a new XML file named my_model_data.xml inside the data directory:

touch data/my_model_data.xml

Open the my_model_data.xml file and add the following content:

<?xml version="1.0" encoding="UTF-8"?>
<odoo>
    <data noupdate="1">
        <record id="my_model_1" model="my.model">
            <field name="name">Sample Model 1</field>
            <field name="description">This is a sample model.</field>
            <field name="active">True</field>
        </record>

        <record id="my_model_2" model="my.model">
            <field name="name">Sample Model 2</field>
            <field name="description">This is another sample model.</field>
            <field name="active">True</field>
        </record>
    </data>
</odoo>

This XML file creates two sample records for our model. The noupdate="1" attribute indicates that this data should not be updated if the module is installed again.

Step 7: Install the Module

Now that we have created all the necessary files, we can install our module. Start your Odoo server and navigate to the Apps menu in the Odoo interface. Click on the “Update Apps List” button to refresh the list of available modules.
Once the list is updated, search for “My Module” and click on the “Install” button to install it.

Step 8: Test the Module

After installing the module, you should see a new menu item called “My Model” in the Odoo interface. Click on it to access the model’s tree view. You can create new records, edit existing ones, and test the functionality of your module.
You can also check the form view by clicking on any record in the tree view. The form view should display the fields we defined in the model.

Conclusion

In this tutorial, we have created a simple custom module in Odoo that adds a new model with a few fields and views. We also defined security rules and created sample data for the model. This is just a basic example, and you can extend the functionality of your module by adding more features, such as workflows, reports, and custom business logic.

Feel free to explore the Odoo documentation and community resources to learn more about Odoo development and best practices. Happy coding!

Additional Resources

• Odoo Documentation
• Odoo Community
• odoo cookbook
• odoo hub
• Qweb Document
• Qweb Template