Introduction

• Importance of Real-time Push Notifications
• Introducing Deno, Supabase, and Firebase Cloud Messaging (FCM)

Server Setup with Deno and Supabase

• Introduction to Deno and its features
• Setting up Supabase client
• Secure configuration management through environment variables

Real-time Database Change Detection

• Introducing the real-time capabilities of Supabase
• Defining interfaces for detecting database changes

Sending Push Notifications using Firebase Cloud Messaging

• Role and importance of FCM
• Obtaining access token using Google service account
• Push notification sending logic from Deno server using FCM

Conclusion

• Advantages of using Deno, Supabase, and FCM
• Contributions of the real-time push notification system to user experience

1. Introduction

Real-time push notifications are a key factor in maximizing user experience in today's digital age. This article explores how to build a real-time push notification system using Deno, Supabase, and Firebase Cloud Messaging (FCM). This article is intended for developers interested in Deno and cloud services.

2. Server Setup with Deno and Supabase

Deno is a modern JavaScript and TypeScript runtime created to overcome the limitations of Node.js. Supabase is an open-source backend service based on PostgreSQL, providing real-time database capabilities. By combining these two technologies, we can build a powerful and flexible backend system.

Code Example: Setting up Supabase client

import { createClient } from 'npm:@supabase/supabase-js@2'
const supabase = createClient(
Deno.env.get('SUPABASE_URL')!,
Deno.env.get('SUPABASE_SERVICE_ROLE_KEY')!

This code shows how to initialize the Supabase client. Here, we use Deno's environment variable functionality to securely manage Supabase connection information.

3. Real-time Database Change Detection

Supabase's Web Hook feature allows you to immediately detect and respond to changes in the database. This allows you to quickly deliver the latest information to users.

Code Example: Defining webhook payload

interface Post {
id: string
title: string
content: string
}
interface WebhookPayload {
type: 'INSERT'
table: string
record: Post
schema: 'public'
}
// When a new post is added to the posts table, send a push notification to all users
Deno.serve(async (req) => {
// Extract the webhook payload from the request.
const payload: WebhookPayload = await req.json()
console.log("payload: ", payload);

These interfaces are defined to handle data change events that occur in Supabase. The Post interface defines the structure of post data, and the WebhookPayload defines the structure of the data received from the webhook.

4. Sending Push Notifications using Firebase Cloud Messaging

FCM is a powerful service that can send push notifications across multiple platforms. By sending notifications through FCM from the Deno server, users can receive new posts or important updates immediately.

Code Example: Sending push notifications through FCM

import serviceAccount from '../serviceAccountKey.json' with { type: 'json' }
// Function to obtain access token from Google service account
const getAccessToken = ({
clientEmail,
privateKey,
}: {
clientEmail: string
privateKey: string
}): Promise => {

This code shows the process of the Deno server sending push notifications using FCM. Here, we use a Google service account to obtain the access token required for FCM.

5. Conclusion

Building a real-time push notification system using Deno, Supabase, and FCM is very useful in modern web development. This system allows developers to provide immediate information delivery and enhanced interaction to users. Through the technologies and code examples introduced in this article, developers can gain the knowledge and tools necessary to build their own real-time notification system.