ts Builder pattern

// The Builder pattern is a design pattern lets you construct complex

// objects step by step and it’s used mainly in the object oriented

// programming paradigm.

// And you can implement the Builder pattern in Typescript is

// very easy and you can use the builder module.
class Builder {

  public build() {

    return new Product();

  }

}
// Then you make a product class :

class Product {

  constructor(private partA: string, private partB: string) {}

}
// Then you make a director class to build the builder:

class Director {

  public build(builder: Builder) {

    builder.buildPartA();

    builder.buildPartB();

  }

}
// Then you make a ConcreteBuilder that implements the Builder interface:

class ConcreteBuilder extends Builder {

  private product: Product;
  public buildPartA() {

    this.product.partA = ‘Part A’;

  }
  public buildPartB() {

    this.product.partB = ‘Part B’;

  }
  public getProduct() {

    const product = this.product;

    this.reset();

    return product;

  }
  public reset() {

    this.product = new Product(”, ”);

  }

}

const builder = new ConcreteBuilder();

const director = new Director();

director.build(builder);

// make a new product

const product = new Product(‘Part A’, ‘Part B’);

// get the product

const newProduct = builder.getProduct();