CODESAMPLE

SOA - JavaScript

SOA JavaScript

The Service-Oriented Architecture (SOA) pattern structures an application as a collection of loosely coupled, interoperable services. Each service encapsulates a specific business function and communicates with others through well-defined interfaces (often APIs). This promotes modularity, reusability, and independent deployment.

This JavaScript example simulates a simple SOA with two services: UserService and ProductService. They expose methods (acting as APIs) for retrieving user and product data, respectively. A ServiceClient orchestrates calls to these services. Using modules and asynchronous functions (Promises) aligns with JavaScript’s common practices for building scalable and maintainable applications. The separation of concerns into distinct services is a core tenet of SOA.

// userService.js
const users = [
  { id: 1, name: 'Alice' },
  { id: 2, name: 'Bob' }
];

export function getUser(id) {
  return new Promise((resolve) => {
    setTimeout(() => { // Simulate network latency
      const user = users.find(u => u.id === id);
      resolve(user);
    }, 50);
  });
}

// productService.js
const products = [
  { id: 101, name: 'Laptop' },
  { id: 102, name: 'Mouse' }
];

export function getProduct(id) {
  return new Promise((resolve) => {
    setTimeout(() => { // Simulate network latency
      const product = products.find(p => p.id === id);
      resolve(product);
    }, 50);
  });
}

// serviceClient.js
import { getUser } from './userService.js';
import { getProduct } from './productService.js';

export async function getOrderDetails(userId, productId) {
  const user = await getUser(userId);
  const product = await getProduct(productId);

  if (user && product) {
    return {
      user: user,
      product: product,
      orderDate: new Date()
    };
  } else {
    return null;
  }
}

// app.js
import { getOrderDetails } from './serviceClient.js';

async function main() {
  const order = await getOrderDetails(1, 101);
  if (order) {
    console.log('Order Details:', order);
  } else {
    console.log('Order not found.');
  }
}

main();