How to use JavaScript and WebSocket to implement a real-time online ordering system

How to use JavaScript and WebSocket to implement a real-time online ordering system

Introduction:
With the popularity of the Internet and the advancement of technology, more and more restaurants Started providing online ordering service. In order to implement a real-time online ordering system, we can use JavaScript and WebSocket technology. WebSocket is a full-duplex communication protocol based on the TCP protocol, which can realize real-time two-way communication between the client and the server. In the real-time online ordering system, when the user selects a dish and places an order, the server can push the order information to the kitchen in real time, and after the kitchen has prepared the food, it can also notify the user in real time that the food is ready. The following will introduce in detail how to use JavaScript and WebSocket to implement a real-time online ordering system, and give specific code examples.

1. Preparation work
First, we need to prepare the following parts:

1. Front-end page: Users can select dishes and submit orders on this page.
2. Server: Receive the user's order information and push it to the kitchen and the user in real time.
3. Kitchen page: Receive and display the user's order information, and notify the user that the meal is ready in real time.

2. Front-end page

1. Introducing the WebSocket JavaScript library
   In the front-end page, we first need to introduce the WebSocket JavaScript library. Add the following code in the tag of HTML:

2. Establishing a WebSocket connection
   In the front-end page, we need to establish a WebSocket connection with the server. In JavaScript, you can use the following code:

const socket = io('http://localhost:3000'); // 替换成实际的服务端地址

3. Listen to messages pushed by the server
   When new messages are pushed from the server, the front-end page needs to be processed accordingly. In JavaScript, you can use the following code:

socket.on('newOrder', order => { // 处理新的订单信息 });

4. Submit order
   When the user selects the dish and clicks the submit order button, the front-end page needs to send the order information to the server. In JavaScript, you can use the following code:

const order = { // 订单信息 }; socket.emit('submitOrder', order);

3. Server

1. Install the WebSocket library
   In the Node.js environment, we can usesocket.ioLibrary to implement WebSocket connection. Execute the following command on the command line to install dependencies:

npm install socket.io

2. Establish a WebSocket connection
   In the server code, we need to create a WebSocket server and listen for client connection requests. In Node.js, you can use the following code:

const io = require('socket.io')(http); // http为Node.js的HTTP服务器 io.on('connection', socket => { // 处理客户端的连接请求 });

3. Receive order information submitted by the client
   When the client submits the order information, the server needs to receive and process it. In the server code, you can use the following code:

socket.on('submitOrder', order => { // 处理订单信息 // 推送订单信息给后厨和用户 io.emit('newOrder', order); });

4. Other logical processing
   According to actual needs, the server can also perform other logical processing, such as order status tracking and inventory management wait.

4. Back Kitchen Page

1. Front-End Page
   The front-end part of the Back Kitchen page is similar to the user’s front-end page. It needs to establish a WebSocket connection and monitor the server. Pushed messages. For specific code, please refer to the code example on the user front-end page.
2. Display order information
   When a new order is pushed from the server, the order information needs to be displayed on the kitchen page. The specific code can be written according to the actual situation.
3. Notify the user that the food is ready
   When the chef prepares the food, a notification message can be sent to the user through WebSocket to inform the user that the food is ready. For specific code, please refer to the code example on the user front-end page.

Summary:
Through the above steps, we can use JavaScript and WebSocket to implement a real-time online ordering system. Users can select dishes and submit orders on the front-end page. The server receives the order and pushes it to the kitchen and users in real time. The kitchen page displays the order and notifies the user in real time that the food is ready. Using WebSocket can achieve real-time two-way communication, improving user experience and restaurant service efficiency.

Code example:
Due to space limitations, a complete code example cannot be given here. However, readers can refer to WebSocket and Node.js related documents, as well as the open source online ordering system sample code, to implement and improve their own real-time online ordering system.

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