How to Create a Custom Odoo Application: A Step-by-Step Guide

Odoo is a robust and versatile open-source ERP (Enterprise Resource Planning) system that empowers businesses to manage various operations such as sales, inventory, accounting, human resources, and much more. One of the core strengths of Odoo is its flexibility and customizability. Whether you’re a developer or a business owner, customizing Odoo to fit your needs is a powerful way to optimize your workflows and create a personalized solution. In this blog post, we will walk you through the process of creating a custom Odoo application.

What is Odoo ERP?

Odoo is a comprehensive ERP system that provides an all-in-one solution for businesses. It offers a wide array of modules that cover everything from accounting to inventory, human resources, sales, CRM, and more. These modules are highly integrated, allowing them to work seamlessly together.

Odoo is designed with scalability in mind, which means it can be used by small businesses to large enterprises. With its user-friendly interface and modular approach, it allows businesses to pick and choose the functionalities that best suit their needs. Moreover, since Odoo is open-source, it gives developers the ability to customize and extend the platform’s capabilities through custom applications and modules.

Can We Customize Odoo Applications?

Yes, one of the major advantages of using Odoo is the ability to customize its applications. Whether you need to add a new feature, modify an existing one, or create a brand-new application, Odoo provides a flexible framework for developers to do so.

The platform offers a powerful set of tools and libraries to build custom applications. By using Python for backend logic and XML for front-end views, Odoo makes it easy to extend or modify the functionality of its standard modules. Custom applications can range from simple add-ons to complex enterprise-level solutions, all integrated seamlessly into the Odoo ecosystem.

Creating a Custom Application

Before diving into the code, you need to prepare a basic environment for creating a custom Odoo application. Here are the essential steps:

Step 1: Set Up Odoo Development Environment

To begin developing a custom Odoo application, you need to install Odoo on your local machine or a development server. You can install Odoo by following the official documentation or using Docker for a quick setup. Make sure you have the necessary development tools such as a code editor (e.g., Visual Studio Code, PyCharm) and Python installed.

Step 2: Create a New Odoo Module

An Odoo application is essentially a module. Each module contains all the necessary files and configurations for your custom application. To create a new module:

1. Navigate to the addons​ directory in your Odoo installation folder.
2. Create a new directory with your module name. For example, create a folder named my_custom_app​.
3. Inside this folder, create a __manifest__.py​ file, which defines the metadata for the module (name, version, dependencies, etc.).

Here is a simple example of the __manifest__.py​ file:

{
    'name': 'My Custom App',
    'version': '1.0',
    'summary': 'A custom Odoo application',
    'category': 'Custom',
    'author': 'Your Name',
    'depends': ['base'],
    'data': [
        'views/my_custom_view.xml',
    ],
}

This __manifest__.py​ file tells Odoo that your module is named “My Custom App,” and it depends on the base​ module, which is required for most Odoo modules.

Step 3: Define the Module Structure

After setting up the manifest, the next step is to define the core structure of your module, such as models, views, and any other elements required.

Adding Custom Models

Models are the core of any Odoo application. A model defines the structure and behavior of your data. Odoo models are written in Python, and they inherit from the models.Model​ class.

Step 1: Define a Model Class

To create a new model for your application, you will define a Python class in a file called models.py​. Each class represents a database table, and its attributes define the columns of the table.

Here's an example of a simple model that stores information about products: 

from odoo import models, fields

class Product(models.Model):
    _name = 'my.custom.product'
    _description = 'Custom Product'

    name = fields.Char(string='Product Name', required=True)
    description = fields.Text(string='Description')
    price = fields.Float(string='Price')

In this example:

• The Product​ class represents a custom product model.
• The _name​ attribute defines the name of the model (which corresponds to the database table).
• The fields.Char​, fields.Text​, and fields.Float​ are field types that define different data types for the columns.

Step 2: Update the Database

After defining the model, you will need to update the database schema by upgrading your module. This can be done via the Odoo interface or by running the following command:

./odoo-bin -u my_custom_app

Adding Custom Views

Once your models are defined, the next step is to create views that will display and allow users to interact with the data. In Odoo, views are defined using XML.

Step 1: Create a View File

To create a view for your model, create an XML file in the views​ folder inside your module directory. Here’s an example of a form view for the Product​ model:

<odoo>
	​<record id="view_product_action" model="ir.actions.act_window">
        <field name="name">my.custom.product.list</field>
        <field name="res_model">my.custom.product</field>
        <field name="view_mode">list,form</field>
	​</record>

	​<record id="view_product_list" model="ir.ui.view">
        <field name="name">my.custom.product.list</field>
        <field name="model">my.custom.product</field>
        <field name="arch" type="xml">
            <list string="Product">
                 <field name="name"/>
                 <field name="description"/>
            	​	​<field name="price"/>
            </list>
        </field>
    </record>    

	​<record id="view_product_form" model="ir.ui.view">
        <field name="name">my.custom.product.form</field>
        <field name="model">my.custom.product</field>
        <field name="arch" type="xml">
            <form string="Product">
                <group>
                    <field name="name"/>
                    <field name="description"/>
                    <field name="price"/>
                </group>
            </form>
        </field>
    </record>
</odoo>

In this XML code:

• The record​ tag defines a new view in Odoo.
• We have created an ir.actions.act_window​ that will be called by a menu (we will cover how to create menu in Step 2). For this actions we can define several field​ values:
• • ​name​ (required): A header name which will be displayed on top of screen.
  • ​res_model​ (required): Contain model's _name​ that is related to this action.
  • ​view_mode​ (required): Contain view types that are going to be available when the actions is viewed. In this case we use list​ and form​ view types.
  • ​target​ (optional): Define where to display the views when user clicks this actions. Common values are either current​, new​, fullscreen​ or main​.
  • ​view_ids​ (optional): Define specific view definitions that are used by this action.
• We created ir.ui.view​ definitions for list​ and form​ view types. For these view definitions we can define severeal field values:
• • ​name​ (required): A name for the view. This is only displayed in Technical Settings using Developer mode.
  • ​model​ (required): Contain model's _name​ that is related to this view.
  • ​arch​ with type xml​ (required): Contains the main XML body which will be rendered for users.

Step 2: Link the View to the Menu

To make your custom view accessible from the Odoo interface, you need to add a menu item that links to the view. You can do this by adding a menuitem​ tag in the same XML file:

<odoo>
	​<menuitem id="menu_my_custom_app" name="My Custom App"/>

    <menuitem 
	​	​id="menu_product" 
	​	​name="Products" 
	​	​parent="menu_my_custom_app" 
	​	​action="view_product_action"/>
</odoo>

In this XML code:

• The first menuitem​only have id​ and name​ attributes. Without a parent​ attribute, this menu will create a root menu that will appear in Odoo main menu.
• The second menuitem​ have id​, name​, parent​ and action​ attributes. With a parent​ attribute, this menu will be created under the specified parent​ menu.
• ​menuitem​ can contain several attributes such as:
• • ​id​ (required): An external ID which uniquely identifies this record in Odoo environment.
  • parent​ (optional): Define whether this menu acts as a main menu (without parent​ attribute) or sub menu under the defined (with)parent​ attribute.
  • ​action​ (optional): Define whether this menu calls any actions or not. If a menu has this attribute but in the same time is a parent​ of another menu, action​ defined will not be called.
  • ​sequence​ (optional): Can be used to sort menus within the same parent​ menu.

Testing and Installing the Custom Application

After you've created your models and views, it’s time to test and install the custom application in Odoo.

Step 1: Install the Custom Module

To install the custom application, navigate to the Odoo Apps menu. If you don’t see your custom app listed, click on “Update Apps List” from the Apps menu to refresh the list.

Once your custom app appears, click “Install” to install it into your Odoo system.

Step 2: Test Your Application

After installing the module, go to the menu item you added for your custom product. Create a new product and check if everything works as expected. Ensure that you can view, edit, and delete records, and check if the fields and views are correctly displayed.

Step 3: Debug and Troubleshoot

If you encounter any issues, check the Odoo logs for error messages. Common issues include incorrect model definitions, missing fields, or misconfigured views.

Conclusion

Creating a custom application in Odoo is a straightforward process that involves setting up a new module, defining models, and creating views. By following the steps outlined above, you can build custom applications to meet your specific business requirements.

Odoo’s flexibility and powerful framework make it an ideal choice for businesses looking to customize their ERP systems, and with a little knowledge of Python and XML, you can create fully tailored applications that integrate seamlessly into the Odoo environment.