Proxy Design Pattern

 //image class created just when it needed

// Subject: Image

class Image {

constructor(url) {

this.url = url;

}

display() {

console.log(`Displaying image from ${this.url}`);

}

}

// Proxy: Virtual Image Proxy

class ImageProxy {

constructor(url) {

this.url = url;

this.realImage = null;

}

display() {

if (this.realImage === null) {

this.realImage = new Image(this.url);

}

this.realImage.display();

}

}

// Usage

const imageProxy = new ImageProxy('image.jpg');

// Image is not loaded yet

imageProxy.display();

// Image is loaded and displayed

imageProxy.display();