How to add a Who-Is-Online feature on your application with JavaScript

In this tutorial, we will guide you through integrating a "Who-Is-Online" feature into your JavaScript application using SuperViz. This feature allows users to see who else is currently online in a shared session, which is especially useful for collaborative tools, virtual events, and social platforms.

We'll demonstrate how to set up a simple React application that uses SuperViz to display the list of online participants. By the end of this tutorial, you'll have a fully functional "Who-Is-Online" feature that you can extend and customize to meet your specific needs.
Let's get started!

Step 1: Set Up Your React Application

To begin, you'll need to set up a new React project where we will integrate SuperViz for the "Who-Is-Online" feature.

1. Create a New React Project

First, create a new React application using Vite with TypeScript.

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npm create vite@latest who-is-online -- --template react-ts
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cd who-is-online

Vite is a modern build tool that provides a faster and more efficient development experience compared to Create React App. It also supports TypeScript out of the box.

2. Install Required Libraries

Next, install the necessary libraries for our project:

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npm install @superviz/sdk uuid

• @superviz/sdk: For integrating real-time collaboration features.
• uuid: A library for generating unique identifiers, useful for creating unique participant IDs.

3. Configure tailwind

In this tutorial, we'll use the Tailwind css framework. First, install the tailwind package.

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npm install -D tailwindcss postcss autoprefixer
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npx tailwindcss init -p

We then need to configure the template path. Open tailwind.config.js in the root of the project and insert the following code.

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/** @type {import('tailwindcss').Config} */
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export default {
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content: [
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"./index.html",
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"./src/**/*.{js,ts,jsx,tsx}",
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],
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theme: {
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extend: {},
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},
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plugins: [],
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}

Then we need to add the tailwind directives to the global CSS file. (src/index.css)

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@tailwind base;
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@tailwind components;
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@tailwind utilities;

4. Set Up Environment Variables

Create a .env file in your project root and add your SuperViz developer key. This key will be used to authenticate your application with SuperViz services.

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VITE_SUPERVIZ_API_KEY=YOUR_SUPERVIZ_DEVELOPER_KEY

Step 2: Implement the Main Application

In this step, we'll implement the main application logic to initialize SuperViz and display the "Who-Is-Online" feature.

1. Implement the App Component

Open src/App.tsx and set up the main application component using SuperViz to manage the online participants list.

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import { useCallback, useEffect, useRef, useState } from "react";
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import SuperVizRoom, { LauncherFacade, WhoIsOnline } from '@superviz/sdk';
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import { v4 as generateId } from 'uuid';

Explanation:

• Imports: Import necessary components from React, SuperViz, and UUID for managing state, initializing SuperViz, and displaying the online participants.

2. Define Constants

Define constants for the API key, room ID, and participant ID.

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const apiKey = import.meta.env.VITE_SUPERVIZ_API_KEY as string;
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const ROOM_ID = 'who-is-online';

Explanation:

• apiKey: Retrieves the SuperViz API key from environment variables.
• ROOM_ID: Defines the room ID for the SuperViz session.

3. Create the App Component

Set up the main App component and initialize the "Who-Is-Online" feature.

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export default function App() {
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  const [initialized, setInitialized] = useState(false);
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  const superviz = useRef<LauncherFacade | null>(null);

Explanation:

• useState & useRef: Manages the initialization state and stores the SuperViz instance.

4. Initialize SuperViz

Create a function to initialize SuperViz and set up the "Who-Is-Online" feature.

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const initialize = useCallback(async () => {
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  if(initialized) return;
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  superviz.current = await SuperVizRoom(apiKey, {
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    roomId: ROOM_ID,
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    participant: {
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      id: generateId(),
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      name: 'participant-name',
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    },
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    group: {
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      id: 'who-is-online',
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      name: 'who-is-online',
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    }
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  });
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  const whoIsOnline = new WhoIsOnline({
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    position: 'who-is-online',
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    disablePresenceControls: true,
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  });
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  superviz.current.addComponent(whoIsOnline);
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  setInitialized(true);
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}, [initialized]);

Explanation:

• initialize: Initializes SuperViz, sets up the real-time component, and adds the "Who-Is-Online" feature to the application.
• WhoIsOnline: Displays the list of participants currently online in the session, positioned within the specified HTML element.

5. Use Effect Hook for Initialization

Use the useEffect hook to trigger the initialize function on component mount and handle cleanup when the component is unmounted.

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useEffect(() => {
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  initialize();
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  return () => {
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    superviz.current?.destroy();
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  }
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}, []);

Explanation:

• useEffect: Calls the initialize function once when the component mounts and cleans up the SuperViz instance when the component unmounts.

Step 3: Render the Who-Is-Online Interface

Finally, return the JSX structure for rendering the "Who-Is-Online" interface.

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return (
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  <div className='w-full h-full bg-gray-200 flex items-center justify-center flex-col'>
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    <header className='w-full p-5 bg-purple-400 flex items-center justify-between'>
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      <h2 className='text-white text-2xl font-bold'>Who is Online</h2>
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    </header>
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    <main className='flex-1 p-20 flex w-full gap-2 items-center justify-center'>
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      <div id="who-is-online"></div>
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    </main>
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  </div>
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);

Explanation:

• Viewer Container: The who-is-online div is where the online participants list will be rendered. This is where users will see who else is online in the session.

Step 4: Understanding the Project Structure

Here's a quick overview of how the project structure supports the "Who-Is-Online" feature in a JavaScript application:

1. App.tsx
   • Initializes SuperViz and sets up the "Who-Is-Online" feature.
   • Handles real-time updates of online participants.
2. Who-Is-Online Interface
   • Displays a list of participants currently online in the session.
   • Updates dynamically as participants join or leave the session.
3. Real-Time Communication
   • Manages real-time communication between participants using SuperViz.

Step 5: Running the Application

1. Start the React Application

To run your application, use the following command in your project directory:

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npm run dev

This command will start the development server and open your application in the default web browser. You can see who else is online in real-time as other participants join.

2. Test the Application

• Who-Is-Online Feature: Open the application in multiple browser windows or tabs to simulate multiple participants and verify that the list of online users updates in real-time.
• Collaborative Interaction: Test the responsiveness of the application by observing how the online participants list changes as users join and leave the session.

Summary

In this tutorial, we built a "Who-Is-Online" feature using SuperViz. We configured a React application to handle real-time updates of online participants, enabling multiple users to see who else is in the session. This setup can be extended and customized to fit various scenarios where real-time presence information is essential.

Feel free to explore the full code and further examples in the GitHub repository for more details.