Abstract Factory Pattern

  • Sprouting
  • c.

The abstract factory pattern is a creational design pattern for creating different varieties of the same type of object.

Example

Real-world analogy: factories specialising in distinct styles of furniture

design-patterns/src/creational/abstract_factory.ts at main

Products

Chairs of any style always share the same function: you use them to sit on. A chair that is in an Art Deco style has the same use as a chair that is in a Victorian style.

type Chair = () => string;


const artDecoChair: Chair = () => "Art Deco chair";
const victorianChair: Chair = () => "Victorian chair";


type CoffeeTable = () => string;


const artDecoCoffeeTable: CoffeeTable = () => "Art Deco coffee table";
const victorianCoffeeTable: CoffeeTable = () => "Victorian coffee table";

Factory

Both a factory specialising in Art Deco furniture, and a factory specialising in Victorian furniture can produce chairs and a coffee tables that function the same as any other chair and coffee table.

interface FurnitureFactory {
  createChair(): Chair;
  createCoffeeTable(): CoffeeTable;
}


class ArtDecoFurnitureFactory implements FurnitureFactory {
  createChair(): Chair {
    return artDecoChair;
  }


  createCoffeeTable(): CoffeeTable {
    return artDecoCoffeeTable;
  }
}


class VictorianFurnitureFactory implements FurnitureFactory {
  createChair(): Chair {
    return victorianChair;
  }


  createCoffeeTable(): CoffeeTable {
    return victorianCoffeeTable;
  }
}

Client

A chair can be ordered from any furniture factory and will always be a chair of that factory’s specfic style. Calling the createChair method on any type of furniture factory will always produce a chair. Calling the createCoffeeTable method on any type of furniture factory will always produce a coffee table.

function orderChair(factory: FurnitureFactory): Chair {
  return factory.createChair();
}


function orderCoffeeTable(factory: FurnitureFactory): CoffeeTable {
  return factory.createCoffeeTable();
}


let factory = new ArtDecoFurnitureFactory();
let chair = orderChair(factory);
console.log(chair());
// Expected output:
// Art Deco chair


let coffeeTable = orderCoffeeTable(factory);
console.log(coffeeTable());
// Expected output:
// Art Deco coffee table


factory = new VictorianFurnitureFactory();
chair = orderChair(factory);
console.log(chair());
// Expected output:
// Victorian chair


coffeeTable = orderCoffeeTable(factory);
console.log(coffeeTable());
// Expected output:
// Victorian coffee table

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