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Ruby on Rails 8: Build a Real-Time Chat & Telegram Features

Name: Ruby on Rails 8: Build a Real-Time Chat & Telegram Features
Rating: 4.8 (8 reviews)

Master Rails: Real-Time Chat App with Group Chats, Online Status, Unread Notifications, PostgreSQL + Redis as Fast DB!

Created byTanja Pavlova

Last updated 11/2025

English

What you'll learn

Develop a fully functional real-time chat system with Ruby on Rails
Integrate Stimulus JS with Rails for smooth and interactive front-end experiences
Use Redis not just for pub/sub, but also for efficient storage and retrieval of unread notification data
Create and work with various types of associations, including polymorphic relationships, for flexible and reusable data structures
Create custom rules and roles for group functionality
Build group access protection mechanisms for users who are not members of the group — enforced on both server and client sides
Create background jobs to asynchronously broadcast the real-time Turbo Stream updates
Use WebSocket lifecycle hooks in Rails Channels to handle real-time online/offline status updates
Leverage Active Storage to manage various types of attachments and user avatars
Use ActionCable and WebSockets for real-time communication
Create a notification system that includes the latest messages and unread notification counts
Learn how to use Devise for authentication and customize its controllers to fit a real-time chat app

Course content

12 sections • 108 lectures • 6h 36m total length

Introduction. What we're going to Build.5:07
Before You Begin: Course Scope & Prerequisites2:54
This introductory lecture explains the scope, structure, and prerequisites of the course.
You will learn what the course focuses on, why the backend is the main emphasis, and how each section builds on the previous one.
Please watch this lecture first to ensure you have the required background knowledge and a clear understanding of how to follow the course step by step.
Realtime Chat App – Setup Instructions1:18
Create a New Rails App with PostgreSQL, TailwindCSS & Devise Gem3:43
Create a Home Page with Devise Authentication2:37
Pages Structure and Model Associations Overview3:19
Create the Contact Model as a Polymorphic Model3:13
Create Rooms and Conversants2:07
Create Group and GroupUser Models. Set Associations2:49
Additional Associations to the User Model: added_users and added_groups1:52
Set Redis as the pub/sub server for ActionCable4:06
Set Active Storage locally1:50
Devise: Login for All Pages Except Home & Set current_user1:11

Contacts Page Structure1:50
Add Name Field to the Users Table. Add Avatar. Change Devise signup/edit Forms3:57
Create Contacts Controller. Set the Routes2:20
Check the changes. Start the server1:05
Create Contacts Page View2:52
Create User and Avatar Partials3:34
We’ll use the User partial to display users in the contacts list, and the Avatar partial to show either the user’s image or the initials of their name. The Avatar partial will also be used in the User and Group partials.
Helper Functions for the Avatar Partial2:29
We’ll create two helper functions to use in the avatar partial.
Create 3 Users and Groups via seeds. Check Contacts Page. Users_path Helper4:50
We’ll create test users and groups, add them to the Arcadia contacts page, and check how they appear.
Create Navigation Partial5:27
The navigation partial appears at the top of the real-time chat app and includes a dropdown menu to log in or sign out of the chat.
Create Flash Partial4:12
We use the flash partial to show success, error, and notice messages to the user.
Create Group Partial4:16
Create Avatar Controller and Routes. Use Turbo Stream to Remove Avatar8:02
Add styling to the Devise pages2:36
Update Rails to 8.0.13:02
Search Block Part 1. Create Search Stimulus Controller. Form_search Partial7:26
Search Part 2. Routes & Search Controller. Models Functions. Found_users Partial7:07

User Page: Features & Interactions2:22
User Page Structure1:26
Create Show Users Page and the Users Controller2:00
Create Top Area and Add/Remove Contact Button to the User Page4:48
Real-Time Messaging. How ActionCable and Redis Keep Everyone in Sync2:43
Create Message Resource as Polymorphic3:41
Add Message Associations to User, Room, and Group Models0:58
Messages Routes: Rails' Routing System for Polymorphic Associations2:04
Create Action in the Messages Controller and Update the frontend UI in real time6:24
Destroy Action in the Messages Controller Update the frontend UI in real time3:51
Create Message Partial4:25
Message Partial displays individual messages and includes the following elements:
The timestamp of when the message was created
A delete button (visible only to the message owner)
The message body (text content)
The sender’s name (shown only in group conversations)
Create a “New Message Form” Partial – used for submitting messages3:49
Form New Message Partial will have the following elements:
Message input field where the user enters the message text
Submit button to send the message
Paperclip icon for the attachments
Create a Chat Room for One-on-One User Conversations6:19
Prevent duplicate entries for the Conversant Model2:22
Finalizing Frontend Broadcasting on the User Page6:23
Check the broadcasting in Redis Insight7:15
Clearing Input after Message Post3:15
Auto-Scrolling Messages in the Chat Area5:57
Auto-Scrolling Messages. User-Friendly Impovement4:46
Realtime Contact List Sync When One User Adds or Removes Another0:12

Group Page: Features & Interactions1:04
User Roles in the Group1:33
Refactoring View Pages: Reusing Common Left Part in Contacts and User Pages2:26
Group Page Basic Structure. Create Group Page & Groups Controller1:39
Group Page Breakdown: Blocks & Partials1:23
Group Page Layout: Deepening the Structure and Creating Messaging Functionality4:20
Create chat_header Partial3:09
Add Content to the Sidebar1:35
Create _avatar_big Partial2:59
Create group_user Partial3:32

Add/Remove Group Users in the realtime chat. Presentation of Concept1:18
Create Functionality. Add Users to the Group. Routes and Actions4:36
Create add_users Form4:39
Finish the action update_users2:24
Create Functionality Remove Users from the Group. GroupsController actions.4:41
Finish the Remove Users Functionality. Create remove_users Page.2:59
Refactoring GroupsController3:44
Javascript Controller to close the modal window2:03
Jobs and background processing. Turbo-Streams for Real-Time Updates.7:08
Group Access Control — Concept & Final Version Overview2:22
Create Group Protection Mechanism: Server-side2:37
Create Group Protection Mechanism: Client-Side6:49
Tweak the Message Partial4:14
Sidebar Toggle Button Functionality4:16

Create/Edit/Remove Group. Final Version Overwiew1:35
Introduction: Kebab Menus with the Links: Add, Edit & Delete Group0:39
Building a Kebab Menu with Partial and Stimulus Controller for Toggle Action3:55
Add Group Workflow1:32
Introduction: Create views for the Groups Actions.0:52
Implementation: Create Views Files: new, edit, _form2:25
Actions New and Create in the groups_controller1:01
Complete Create Group. Add admin to the Group Users + Broadcast changes1:54
Actions Edit, Update and Destroy in the groups_controller. Delete Broadcast Job4:26
Add Avatar to the Group. Create avatars_controller for the Group3:40
Create GroupUpdateJob to bradcast the group updates in real-time4:12
Broadcast User's Profile Update in real-time5:05

Introduction: Unread Notifications + Last Message Preview in Real-Time2:15
Create Last Message Preview2:19
Explanation: Create the Real-Time Functionality for the Last Message Preview3:07
Implementation: Real-Time Last Message Preview with LastMessageJob7:43
Introduction: Real-Time Unread Notification Count Workflow2:21
Redis Setup: Install Pond for Counter Management1:48
Implementation Workflow: Adding Unread Notification Counts in Real-Time11:19
Introduction Workflow: Delete Unreal Notification Count after Message delete.1:22
Implementation: Delete Unread Notifications in Real Time on Message Deletion9:29
Fetch Unread Notification Counts on Page Load6:34
Implementation. Cleaning Redis When Notifications Are Read on Page Load4:08
Implementation. Mark Notification as Read in Real-Time7:07

Online/Offline Mode: Goal Preview, Backend Workflow, View & User Model Setup9:54
This feature shows users' online and offline status in real time. It uses an Action Cable channel with WebSocket connection events, including both backend logic and a small frontend subscription.
Change the Mode After Sign In & Sign Out. Backend Implementation9:09
In this lecture, we'll set up the channel and implement a backend method mark_user_mode(user, mode), which will be triggered during Devise sign-in and sign-out events.
Online/Offline Mode with Inactivity Tracking. Frontend Implementation8:58
Real-time online/offline mode updates will be handled via a Stimulus controller integrated into the UserMode channel, based on user activity and inactivity tracking.

Requirements

Basic knowledges of Ruby on Rails, such as Model-View-Controller (MVC) design pattern, RESTFUL API's requests, basic knowledges of javascript.

Description

Unlock the full potential of Ruby on Rails 8 by building a powerful, real-time chat application inspired by the Telegram Web app.

In this fast-paced, practical course, you'll create private and group chat rooms with features like live messaging, user presence, unread notifications, and file attachments. You'll also manage authentication, user roles, and permissions — all in real time.

We’ll use modern Rails tools and technologies, including:

Devise for authentication
ActionCable & WebSockets for bi-directional, live communication
Redis for real-time unread notification counts as the database and as the Pub/Sub broker for all data updates
Stimulus JS for dynamic frontend behavior
Active Storage for uploading avatars and sharing files
Polymorphic associations and other advanced ActiveRecord patterns
Rails Channels and WebSocket lifecycle hooks to track user online/offline status in real time.

You’ll also learn how to:

Build real-time group membership and role systems
Secure Group Page from Unauthorized Visits on Server and Client Side in Real Time
Display last messages and unread message counts — instantly

Throughout the course, we’ll explain complex backend logic using visual diagrams and schemas to make everything clear and digestible.

This course is compact and efficient — just around 6 hours — carefully designed to save your time and deliver only the most relevant, high-impact knowledge. Each lecture builds directly on the last, so it's important to follow in sequence for a smooth learning experience.

Who is this course for?

This course is perfect for Rails developers with basic knowledge of MVC, routing, and RESTful APIs, who want to go beyond CRUD and build something dynamic and production-ready. Familiarity with JavaScript will also help, as we’ll use Stimulus JS for frontend interactions.

If you’ve always wanted to build a real-time app with Rails — this is your blueprint.

F.A.Q

Q: Will I receive support during the course?
A: Due to having over 50,000 students across multiple platforms and a full-time job, the instructor isn’t able to provide one-on-one assistance.

Q: Is this course kept up to date?
A: Absolutely. The course is currently updated and fully compatible with Django 5.0.

Q: Do I get lifetime access after purchasing?
A: Yes. Once you purchase the course, you’ll have lifetime access, and it will remain available on Udemy.

Q: Why are the frontend sections only briefly explained?

A: To keep the course concise and focused, I provide the frontend code with short explanations so you can understand how it connects to the backend logic. The intention is not to deep-dive into frontend frameworks or UI design, but to let you see the complete application flow while keeping the total duration manageable.

Q: Why does this course focus mostly on the backend?

A: This course is intentionally designed to help you master backend development with Ruby on Rails. The goal is to give you a clear, practical understanding of backend concepts such as architecture, models, controllers, and database integration — without spending excessive time on frontend topics.

Who this course is for:

Ruby on Rails developers with basic knowledge who want to deepen their core backend skills, better understand database relationships, and master modern real-time application development

Ruby on Rails 8: Build a Real-Time Chat & Telegram Features

What you'll learn

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Course content

Basic Setup13 lectures • 36min

Contacts Page16 lectures • 1hr 5min

User Page & Messaging System20 lectures • 1hr 15min

Group Page Structure10 lectures • 24min

Real-Time Group Membership & Access Permissions14 lectures • 54min

Managing Groups & User Profiles in Real-Time12 lectures • 31min

Notification System in Real-Time: Unread Count + Last Message Preview12 lectures • 1hr

Attachments2 lectures • 10min

Online/Offline User Mode3 lectures • 28min

Additional Features1 lecture • 3min

Requirements

Description

Who this course is for: