Lazy initialize object with Proxy Pattern

Dec 1, 2018

Sometimes, you want to lazy intialize an object such as websocket to make it’s only connected when needed, (virtual) proxy pattern can help.

Instead of initializing directly:

const socket = new Websocket(url);

Using the Proxy:

// The proxy controls a web socket instance
class WebSocketProxy {
    constructor(options) {
        this.options = options;
    }

    connect() {
        if (this.socket) {
            return this.socket;
        }
        this.socket = new Websocket(this.options.url);
        return this.socket;
    }
}

const socket = new WebSocketProxy({ url: 'wss://www.example.com/socketserver' });
socket.connect();