Real-World Factory Examples

Introduction

Factories are used extensively in real-world applications for creating objects with complex setup, conditional logic, or configuration.

UI Component Factory

function createButton(type, label) {
  const button = document.createElement('button');
  button.textContent = label;

  switch (type) {
    case 'primary':
      button.className = 'btn btn-primary';
      break;
    case 'secondary':
      button.className = 'btn btn-secondary';
      break;
    case 'danger':
      button.className = 'btn btn-danger';
      break;
  }

  return button;
}

const saveBtn = createButton('primary', 'Save');
const deleteBtn = createButton('danger', 'Delete');

API Client Factory

function createHttpClient(baseURL, options = {}) {
  const defaults = {
    timeout: 5000,
    retries: 3,
    headers: { 'Content-Type': 'application/json' }
  };

  const config = { ...defaults, ...options };

  return {
    async get(endpoint) { /* ... */ },
    async post(endpoint, data) { /* ... */ },
    async put(endpoint, data) { /* ... */ },
    async delete(endpoint) { /* ... */ },
    setAuth(token) { config.headers.Authorization = `Bearer ${token}`; }
  };
}

const api = createHttpClient('https://api.example.com', { timeout: 10000 });

Summary

UI element creation with conditional styling
API client configuration with defaults
Model instantiation with different strategies
Dependency injection containers

Real-World Factory Examples

Real-World Factory Examples

Introduction

UI Component Factory

API Client Factory

Summary

Further Reading