How to build a public OneSignal integration: Building the Auth Flow

Aug 14, 2024 • 6 minute read

Hey there, fellow JavaScript enthusiasts! Ready to dive into the world of OneSignal integrations? Today, we're going to walk through building a rock-solid authorization flow for a user-facing OneSignal integration. Buckle up, because we're about to make push notifications a whole lot cooler!

What's the deal with OneSignal?

OneSignal is the go-to platform for push notifications, and for good reason. It's powerful, flexible, and can reach users across multiple platforms. But to harness its full potential, we need to build a smooth authorization flow. That's where the magic happens!

Before we jump in

Make sure you've got these bases covered:

A OneSignal account with API credentials (you rockstar, you)
Node.js and npm installed on your machine
A solid grasp of OAuth 2.0 (don't worry, we'll refresh your memory)

Setting up shop

Let's get our project off the ground:

Fire up your terminal and create a new Node.js project:

mkdir onesignal-integration && cd onesignal-integration
npm init -y

Install the essentials:
```
npm install express axios dotenv
```

Configuring OneSignal API

Time to get cozy with OneSignal:

Head over to the OneSignal dashboard and register your application
Grab your client ID and client secret (guard these with your life!)
Set up a redirect URI (something like http://localhost:3000/callback)

The main event: Implementing the auth flow

Here's where the rubber meets the road. Let's build this flow!

require('dotenv').config();
const express = require('express');
const axios = require('axios');

const app = express();

app.get('/auth', (req, res) => {
  const authUrl = `https://onesignal.com/oauth/authorize?client_id=${process.env.CLIENT_ID}&response_type=code&redirect_uri=${encodeURIComponent(process.env.REDIRECT_URI)}`;
  res.redirect(authUrl);
});

app.get('/callback', async (req, res) => {
  const { code } = req.query;
  
  try {
    const tokenResponse = await axios.post('https://onesignal.com/oauth/token', {
      grant_type: 'authorization_code',
      code,
      redirect_uri: process.env.REDIRECT_URI,
      client_id: process.env.CLIENT_ID,
      client_secret: process.env.CLIENT_SECRET
    });

    // Store the access token securely
    const accessToken = tokenResponse.data.access_token;
    
    res.send('Authorization successful!');
  } catch (error) {
    console.error('Error exchanging code for token:', error);
    res.status(500).send('Authorization failed');
  }
});

app.listen(3000, () => console.log('Server running on port 3000'));

Making it pretty

Let's add a touch of UI magic:

<!DOCTYPE html>
<html>
<head>
  <title>OneSignal Integration</title>
</head>
<body>
  <h1>Connect to OneSignal</h1>
  <button onclick="window.location.href='/auth'">Connect</button>
  <div id="status"></div>
  <script>
    // Add some JavaScript to update the status
  </script>
</body>
</html>

Locking it down

Security is key, folks. Here are some pro tips:

Implement PKCE (Proof Key for Code Exchange) for added security
Set up a token refresh mechanism
Store tokens securely (please, no plain text storage!)

Taking it for a spin

Fire up your server and navigate to your auth page. Click that connect button and watch the magic unfold! If all goes well, you should see a successful authorization message.

When things go sideways

Error handling is crucial. Make sure to:

Handle common errors like expired tokens or network issues
Provide clear, user-friendly error messages
Log errors for debugging (your future self will thank you)

Wrapping up

And there you have it! You've just built a slick authorization flow for your OneSignal integration. Pat yourself on the back – you've earned it!

Remember, this is just the beginning. From here, you can expand your integration to do all sorts of cool stuff with push notifications. The sky's the limit!

Want to learn more?

Check out these resources to level up your OneSignal game:

Now go forth and notify the world! Happy coding!