How to Extend Django User Model using Proxy Models

Django’s User model provides a solid foundation for authentication, but as projects grow, additional user-specific attributes may be necessary. Extending the User model via proxy models offers a unique approach to customization. In this blog, we’ll explore how to extend Django User Model using the Proxy Model method, supported by a comprehensive example.

Understanding Proxy Models

Proxy models allow you to create a subclass of the User model, inheriting its fields and behaviors, while adding your custom methods or attributes. This approach retains the underlying database structure while introducing new functionality.

Benefits of Proxy Models

Modularity: Extend User model functionality without modifying the original User structure.
Database Consistency: Retain a single database table, simplifying database management.
Efficiency: Easily integrate additional attributes and methods while relying on the existing User authentication.

Step-by-Step Implementation

Let’s dive into the process of extending Django User Model using the Proxy Model method, utilizing a practical example of a CustomUser model.

Note: We have create a already created our django project using using our blog on Django Basic Template Boilerplate Skeleton Project. For this example, we have created a app named “accounts“.

Step 1: Create a Proxy Model

# accounts/models.py

from django.contrib.auth.models import User

class CustomUser(User):
    class Meta:
        proxy = True

    def custom_method(self):
        # Add custom logic here

Examples:

class CustomUser(User):
    class Meta:
        proxy = True

    def custom_method_username(self):
        # Example custom logic: Check if the user's username contains 'admin'
        if 'admin' in self.username.lower():
            return f"{self.username} is an admin user."
        else:
            return f"{self.username} is a regular user."
    
    def custom_method_birthdate(self):
        # Example custom logic: Calculate the user's age based on birthdate
        from datetime import date

        if self.birthdate:
            today = date.today()
            age = today.year - self.birthdate.year - ((today.month, today.day) < (self.birthdate.month, self.birthdate.day))
            return f"{self.username} is {age} years old."
        else:
            return f"The birthdate for {self.username} is not available."

In the custom_method_username performs a simple check to see if the username contains the word ‘admin’. If it does, the method returns a message indicating that the user is an admin; otherwise, it states that the user is a regular user. This demonstrates how you can introduce custom logic to the proxy model to provide additional information or behavior based on the existing fields of the User model. Keep in mind that the custom logic you implement can be as simple or complex as needed for your specific use case.

In the custom_method_birthdate calculates the age of the user based on their birthdate. If the birthdate is provided in the birthdate field, the method calculates the age and returns a message indicating the user’s age. If the birthdate is not available, it provides a message stating that the birthdate is not provided. This showcases how you can create more complex custom logic within the proxy model to offer meaningful information or behavior based on the available user data.

Step 2: Access Custom Functionality

With the proxy model, you can access the custom method directly from instances of the CustomUser model, such as user.custom_method().

Step 3: Applying Migrations

Run the following commands to apply migrations and create the one to one link User model:

python manage.py makemigrations
python manage.py migrate

Conclusion

Extending Django User Model using the Proxy Model method offars a creative way to introduce custom attributes and methods while keeping the original User model intact. As demonstrated by the CustomUser example in this blog, proxy models enable you to enhance your application with tailored functionalities. By understanding the potential of proxy models, you gain the flexibility to extend Django’s User model in a manner that aligns with your project’s requirements. Remember that selecting the right extension method depends on your project’s complexity and goals, and the Proxy Model method provides a powerful mechanism to achieve your customization needs.

Find this project on Github.