Builder

Builder Pattern is a creational design pattern that lets you construct complex objects step by step. The pattern allows you to produce different types and representations of an object using the same construction code.

Implementation

class Builder {
  constructor() {
    this.reset();
  }

  reset() {
    this.product = new Product();
  }

  producePartA() {
    this.product.parts.push('PartA');
  }

  producePartB() {
    this.product.parts.push('PartB');
  }

  producePartC() {
    this.product.parts.push('PartC');
  }

  getProduct() {
    const result = this.product;
    this.reset();
    return result;
  }
}

class Product {
  constructor() {
    this.parts = [];
  }

  listParts() {
    console.log(`Product parts: ${this.parts.join(', ')}`);
  }
}

class Director {
  setBuilder(builder) {
    this.builder = builder;
  }

  buildMinimalViableProduct() {
    this.builder.producePartA();
  }

  buildFullFeaturedProduct() {
    this.builder.producePartA();
    this.builder.producePartB();
    this.builder.producePartC();
  }
}

function clientCode(director) {
  const builder = new Builder();
  director.setBuilder(builder);

  director.buildMinimalViableProduct();
  builder.product.listParts();

  director.buildFullFeaturedProduct();
  builder.product.listParts();

  director.buildMinimalViableProduct();
  builder.product.listParts();

  console.log(builder.product);
}

const director = new Director();
clientCode(director);

Builder

Implementation

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