Factory pattern

Information drawn from

Medium - Javascript design patterns by Soumyajit Pathak

Codepen example

Essential JS design patterns book

Factory pattern is a class-based creational pattern. It provides a generic interface that delegates the responsibility of object instantiation to its subclasses.

This pattern is frequently used when we need to manage or manipulate collections of objects that are different yet have many similar characteristics.

Javascript Example

class BallFactory {
  constructor() {
    this.createBall = type => {
      let ball;

      if (type === "soccer" || type === "football") {
        ball = new Football();
      } else if (type === "basketball") {
        ball = new Basketball();
      }
      ball.roll = () => {
        console.log(`The ${type} is rolling`);
      };

      return ball;
    };
  }
}

class Football {
  constructor() {
    this._type = "football";
    this.kick = () => {
      console.log("You kicked the football");
    };
  }
}

class Basketball {
  constructor() {
    this._type = "basketball";
    this.bounce = () => {
      console.log("You bounced the basketball");
    };
  }
}

// creating objects
const factory = new BallFactory();
const myFootball = factory.createBall("football");
const myBasketball = factory.createBall("basketball");

myFootball.roll();
myBasketball.roll();

myFootball.kick();

myBasketball.bounce();

------------------------------------------------------------------------

Last update on 20 Feb 2020

---