• See it live!

• Previous messages are rendered when user access the page, after it, when user sends a message, user will send it to an API endpoint POST (/api/v1/messages).

• When a message arrives in that endpoint the MessageBroadcastJob is started, and responds the client-side immediately with a :no_content status. It uses the job because I think a real-time chat should not block the I/O.

• The MessageBroadcastJob broadcasts the message to all users. It uses the MessageService, that will create the message in database and return the rendered message.

• After a message is created the AttachmentBroadcastJob is started, this job will use AttachmentService to look for URLs in the message body. It'll visit each URL to get its contents.

• Again, it's on a job, the message gets immediately back to the user (real-time), and through the job that is created later, user will receive those attachments.

This way we've a real-time asynchronous chat. The user receives every message almost instantaneously and a few microseconds/seconds later, user will see the attachments.

• Ruby 2.3.1
• Rails 5.0.x
• PostgreSQL 9.3
• Redis for production

There's a setup file, so you can just use:

git clone https://github.com/matheusazzi/simple-messenger.git
cd simple-messenger
./bin/setup