Implementing a Real-Time Chat Application Using WebSockets in Go

Creating a real-time chat application can be an excellent project for understanding WebSocket connections. WebSockets allow you to open an interactive session between a client and a server. In this article, we'll walk through the steps required to implement a real-time chat application using the Go programming language.

Setting Up the Project

To get started, let's create a new directory for the chat application project:

bash

$ mkdir go-chat

$ cd go-chat

Next, initialize a new Go module:

bash
$ go mod init go-chat

Installing Dependencies

We'll need the gorilla/websocket package for WebSocket support. Install the package with:

bash

$ go get github.com/gorilla/websocket

Creating the WebSocket Server

Now, let's implement a basic WebSocket server that will handle WebSocket connections, messages reception, and broadcasting.

go
package main

import (
    "fmt"
    "net/http"
    "github.com/gorilla/websocket"
)

var upgrader = websocket.Upgrader{
    CheckOrigin: func(r *http.Request) bool {
        return true
    },
}

func handleConnections(w http.ResponseWriter, r *http.Request) {
    ws, err := upgrader.Upgrade(w, r, nil)
    if err != nil {
        fmt.Println(err)
        return
    }
    defer ws.Close()

    for {
        messageType, message, err := ws.ReadMessage()
        if err != nil {
            fmt.Println(err)
            break
        }
        fmt.Printf("Received: %s\n", message)

        if err := ws.WriteMessage(messageType, message); err != nil {
            fmt.Println(err)
            break
        }
    }
}

func main() {
    fs := http.FileServer(http.Dir("./public"))
    http.Handle("/", fs)
    http.HandleFunc("/ws", handleConnections)

    if err := http.ListenAndServe(":8080", nil); err != nil {
        fmt.Println(err)
    }
}

Frontend: Simple HTML and JavaScript Client

Let's create a simple HTML file with JavaScript to connect to our WebSocket server:

html



    
    Go Chat


    Real-Time Chat
    
    Send
    

    
        const ws = new WebSocket('ws://localhost:8080/ws');

        ws.onmessage = function(event) {
            const messages = document.getElementById('messages');
            const message = document.createElement('li');
            message.textContent = event.data;
            messages.appendChild(message);
        };

        document.getElementById('sendBtn').onclick = function() {
            const messageInput = document.getElementById('message');
            ws.send(messageInput.value);
            messageInput.value = '';
        };

Running Your Chat Application

To run your chat application, you'll need to open a terminal and execute:

bash
$ go run .

You can access your chat application by opening a web browser and navigating to http://localhost:8080.

Conclusion

In this tutorial, we covered how to create a simple real-time chat application using Go and WebSockets. This is just the foundation, and you can further enhance it by adding features such as user authentication, private messaging, and chat rooms.