Django Channels Tutorial on CS 347

Tutorial Part 1: Basic Setup

Mon, 01 Jan 0001 00:00:00 +0000

Note

If you encounter any issue during your coding session, please see the Channels troubleshooting section.

In this tutorial we will build a simple chat server. It will have two pages:

An index view that lets you type the name of a chat room to join.
A room view that lets you see messages posted in a particular chat room.

The room view will use a WebSocket to communicate with the Django server and listen for any messages that are posted.

Tutorial Part 2: Implement a Chat Server

Mon, 01 Jan 0001 00:00:00 +0000

This tutorial begins where Tutorial 1 left off. We’ll get the room page working so that you can chat with yourself and others in the same room.

Add the room view

We will now create the second view, a room view that lets you see messages posted in a particular chat room.

Create a new file chat/templates/chat/room.html. Your app directory should now look like:

chat/
    __init__.py
    templates/
        chat/
            index.html
            room.html
    urls.py
    views.py

Create the view template for the room view in chat/templates/chat/room.html:

Tutorial Part 3: Rewrite Chat Server as Asynchronous

Mon, 01 Jan 0001 00:00:00 +0000

This tutorial begins where Tutorial 2 left off. We’ll rewrite the consumer code to be asynchronous rather than synchronous to improve its performance.

Rewrite the consumer to be asynchronous

The ChatConsumer that we have written is currently synchronous. Synchronous consumers are convenient because they can call regular synchronous I/O functions such as those that access Django models without writing special code. However asynchronous consumers can provide a higher level of performance since they don’t need to create additional threads when handling requests.

Tutorial Part 4: Automated Testing

Mon, 01 Jan 0001 00:00:00 +0000

This tutorial begins where Tutorial 3 left off. We’ve built a simple chat server and now we’ll create some automated tests for it.

Testing the views

To ensure that the chat server keeps working, we will write some tests.

We will write a suite of end-to-end tests using Selenium to control a Chrome web browser. These tests will ensure that:

when a chat message is posted then it is seen by everyone in the same room
when a chat message is posted then it is not seen by anyone in a different room

Install the Chrome web browser, if you do not already have it.