Sharing Content on Your Website

In the previous chapter, you added success and error messages to your site using the Django messages framework. You also created an email authentication backend and added social authentication to your site using Google. You learned how to run your development server with HTTPS on your local machine using Django Extensions. You customized the social authentication pipeline to create a user profile for new users automatically.

In this chapter, you will learn how to create a JavaScript bookmarklet to share content from other sites on your website, and you will implement asynchronous browser requests in your project using JavaScript and Django.

This chapter will cover the following topics:

• Creating many-to-many relationships
• Customizing behavior for forms
• Using JavaScript with Django
• Building a JavaScript bookmarklet
• Generating image thumbnails using easy-thumbnails
• Implementing asynchronous HTTP requests...

Before you begin: Join our book community on Discord

Give your feedback straight to the author himself and chat to other readers on the book's dedicated Discord server (find the "early-access-fifth-edition" channel under "FEEDBACK AND SUGGESTIONS").

https://packt.link/D5BE

In the previous chapter, you built user registration and authentication into your website. You implemented password change, reset, and recovery functionalities, and you learned how to create a custom profile model for your users.

In this chapter, you will add social authentication to your site using Google. You will use Django Social Auth to implement social authentication using OAuth 2.0, the industry-standard protocol for authorization. You will also modify the social authentication pipeline to create a user profile for new users automatically.

This chapter will cover the following points:

• Using the messages framework
• Building a custom authentication backend
• Preventing users from using...

Technical requirements

The source code for this chapter can be found at https://github.com/PacktPublishing/Django-5-by-example/tree/main/Chapter05.

All Python packages used in this chapter are included in the requirements.txt file in the source code for the chapter. You can follow the instructions to install each Python package in the following sections, or you can install all requirements at once with the command pip install -r requirements.txt.

Using the messages framework

When users are interacting with the platform, there are many cases where you might want to inform them about the result of specific actions. Django has a built-in messages framework that allows you to display one-time notifications to your users.

The messages framework is located at django.contrib.messages and is included in the default INSTALLED_APPS list of the settings.py file when you create new projects using python manage.py startproject. The settings file also contains the middleware django.contrib.messages...

Building a custom authentication backend

Django allows you to authenticate users against different sources. The AUTHENTICATION_BACKENDS setting includes a list of authentication backends available in the project. The default value of this setting is the following:

['django.contrib.auth.backends.ModelBackend']

The default ModelBackend authenticates users against the database using the User model of django.contrib.auth. This is suitable for most web projects. However, you can create custom backends to authenticate your users against other sources, such as a Lightweight Directory Access Protocol (LDAP) directory or any other system.

You can read more information about customizing authentication at https://docs.djangoproject.com/en/5.0/topics/auth/customizing/#other-authentication-sources.

Whenever the authenticate() function of django.contrib.auth is used, Django tries to authenticate the user against each of the backends defined in AUTHENTICATION_BACKENDS one by one, until one...

Adding social authentication to your site

Social authentication is a widely used feature that allows users to authenticate using their existing account of a service provider using Single Sign-on (SSO). The authentication process allows users to authenticate into the site using their existing account from social services like Google, Facebook, or Twitter. In this section, we will add social authentication to the site using Google.

To implement social authentication, we will use the OAuth 2.0 industry-standard protocol for authorization. OAuth stands for Open Authorization. OAuth 2.0 is a standard designed to allow a website or application to access resources hosted by other web apps on behalf of a user. Google uses the OAuth 2.0 protocol for authentication and authorization.

Python Social Auth is a Python module that simplifies the process of adding social authentication to your website. Using this module, you can let your users log in to your website using their accounts from other services...

Additional resources

The following resources provide additional information related to the topics covered in this chapter:

• Source code for this chapter – https://github.com/PacktPublishing/Django-5-by-example/tree/main/Chapter05
• The Django messages framework – https://docs.djangoproject.com/en/5.0/ref/contrib/messages/
• Custom authentication sources – https://docs.djangoproject.com/en/5.0/topics/auth/customizing/#other-authentication-sources
• Automatic primary key fields – https://docs.djangoproject.com/en/5.0/topics/db/models/#automatic-primary-key-fields
• Python Social Auth – https://github.com/python-social-auth
• Python Social Auth’s authentication backends – https://python-social-auth.readthedocs.io/en/latest/backends/index.html#supported-backends
• Django allowed hosts setting – https://docs.djangoproject.com/en/5.0/ref/settings/#allowed-hosts
• Django Extensions documentation – https://django-extensions.readthedocs.io/en/latest...

Summary

In this chapter, you added messages to your project using the Django messages framework. You also created a custom authentication backend to let users log into your site using their email address.

You added social authentication to your site so that users can use their existing Google accounts to log in. You used Python Social Auth and implemented social authentication using OAuth 2.0, the industry-standard protocol for authorization. You also learned how to serve your development server through HTTPS using Django Extensions. Finally, you customized the authentication pipeline to create user profiles for new users automatically.

In the next chapter, you will create an image bookmarking system. You will create models with many-to-many relationships and customize the behavior of forms. You will learn how to generate image thumbnails and how to build AJAX functionalities using JavaScript and Django.

Summary

In this chapter, you created models with many-to-many relationships and learned how to customize the behavior of forms. You built a JavaScript bookmarklet to share images from other websites on your site. This chapter has also covered the creation of image thumbnails using the easy-thumbnails application.

Finally, you implemented AJAX views using the JavaScript Fetch API and added infinite scroll pagination to the image list view.

In the next chapter, you will learn how to build a follow system and an activity stream. You will work with generic relations, signals, and denormalization. You will also learn how to use Redis with Django to count image views and generate an image ranking.

Additional resources

The following resources provide additional information related to the topics covered in this chapter:

• Source code for this chapter: https://github.com/PacktPublishing/Django-5-by-example/tree/main/Chapter06
• Database indexes: https://docs.djangoproject.com/en/5.0/ref/models/options/#django.db.models.Options.indexes
• Many-to-many relationships: https://docs.djangoproject.com/en/5.0/topics/db/examples/many_to_many/
• Requests HTTP library for Python: https://docs.djangoproject.com/en/5.0/topics/db/examples/many_to_many/
• Pinterest Save extension: https://help.pinterest.com/en/article/save-pins-with-the-pinterest-browser-button
• Static content for the account application: https://github.com/PacktPublishing/Django-5-by-Example/tree/main/Chapter06/bookmarks/images/static
• CSS selectors: https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Selectors
• Locating DOM elements using CSS selectors: https://developer.mozilla.org...