Micro Frontend Architecture for Developers

Micro frontends should have minimal dependencies on each other. This ensures that changes in one unit do not require modifications in other units. Communication between micro frontends should be facilitated through well-defined APIs or messaging systems.

While micro frontends should be independent, it's common to share components across multiple units. This promotes consistency and reduces code duplication. Libraries and frameworks for component management can help streamline this process.

A central routing mechanism is required to manage navigation across different micro frontends. This can be achieved using a dedicated routing service or by leveraging the capabilities of a framework like React Router.

Micro frontends need to communicate with each other to share data and events. Common communication mechanisms include custom events, message brokers, or APIs. Choosing the right communication approach depends on the specific requirements of the application.

Popular Micro Frontend Implementations

Several popular implementations and frameworks have emerged to facilitate the development and deployment of micro frontends. Here's a look at some of the most widely adopted approaches:

Single-SPA is a JavaScript framework that allows you to compose multiple independent frontend applications into a single, unified user experience. It acts as a central hub, coordinating the lifecycle of different micro frontends and managing their routing and communication.

Bit is a platform that enables you to build and share micro frontends as independent components. It provides tools for developing, testing, and publishing micro frontends, making it easier to reuse them across different applications.

Piframe is a micro frontend framework that simplifies the integration and communication between micro frontends. It uses a server-side component model to render and manage micro frontends, providing a centralized control point for the application.

Module Federation

Module Federation, a feature introduced in Webpack 5, enables micro frontend applications to share code and dependencies dynamically. This allows micro frontends to access and reuse each other's code, promoting collaboration and reusability.

Building a Micro Frontend Application

Let's explore a simple example of building a micro frontend application using Single-SPA and React. This tutorial will demonstrate the basic principles of Micro Frontend Architecture and provide a hands-on experience.

Step 1: Setting up the Project

We'll start by creating three separate projects: one for the root application and two for the micro frontends.

• Root Application: This project will host the Single-SPA framework and manage the lifecycle of the micro frontends.
• Micro Frontend 1 (Product): This micro frontend will display product information.
• Micro Frontend 2 (Cart): This micro frontend will handle the shopping cart functionality.

Step 2: Installing Dependencies

Install the necessary dependencies for each project:

• Root Application:

      npm install single-spa
  

• Micro Frontend 1 (Product):

      npm install react react-dom react-router-dom
  

• Micro Frontend 2 (Cart):

      npm install react react-dom react-router-dom
  

Step 3: Defining Micro Frontend Entry Points

Each micro frontend needs to define an entry point that will be loaded and registered by Single-SPA.

• Micro Frontend 1 (Product): Create a file named src/product.js and add the following code:

      import React from 'react';
      import ReactDOM from 'react-dom/client';
      import App from './App';
  
      const root = ReactDOM.createRoot(document.getElementById('root'));
      root.render();
  
      export function bootstrap() {
        return Promise.resolve();
      }
  
      export function mount(props) {
        return Promise.resolve();
      }
  
      export function unmount(props) {
        return Promise.resolve();
      }
  

• Micro Frontend 2 (Cart): Create a file named src/cart.js and add the following code:

      import React from 'react';
      import ReactDOM from 'react-dom/client';
      import App from './App';
  
      const root = ReactDOM.createRoot(document.getElementById('root'));
      root.render();
  
      export function bootstrap() {
        return Promise.resolve();
      }
  
      export function mount(props) {
        return Promise.resolve();
      }
  
      export function unmount(props) {
        return Promise.resolve();
      }
  

Step 4: Registering Micro Frontends in the Root Application

In the root application, register the micro frontends using the Single-SPA framework.

import * as singleSpa from 'single-spa';

singleSpa.registerApplication(
  'product',
  () => System.import('./product/src/product.js'),
  {
    path: '/product',
  }
);

singleSpa.registerApplication(
  'cart',
  () => System.import('./cart/src/cart.js'),
  {
    path: '/cart',
  }
);

singleSpa.start();

Step 5: Building and Serving the Application

Build each project and serve the root application. The micro frontends will be dynamically loaded and rendered based on the configured routes.

// Build the root application
npm run build

// Build Micro Frontend 1 (Product)
npm run build

// Build Micro Frontend 2 (Cart)
npm run build

// Serve the root application
npm start

Step 6: Running the Application

Access the root application in your browser. The micro frontends will be dynamically loaded and rendered as you navigate between the defined routes.

Best Practices for Micro Frontend Architecture

Implementing a successful Micro Frontend Architecture requires following best practices to ensure scalability, maintainability, and a seamless user experience:

• Clear Separation of Concerns: Each micro frontend should focus on a specific feature or business domain, avoiding overlapping responsibilities.
• Well-Defined APIs: Establish clear communication channels between micro frontends using well-defined APIs or messaging systems.
• Consistent UI/UX: Ensure a unified user experience across micro frontends by adhering to shared design guidelines and component libraries.
• Robust Testing Strategies: Implement comprehensive testing for each micro frontend to ensure functionality and stability.
• Centralized Monitoring and Logging: Establish centralized monitoring and logging mechanisms to gain insights into the performance and health of micro frontends.
• Code Reusability: Encourage code sharing and reusability through shared component libraries and patterns.
• Versioning and Release Management: Implement version control and release management strategies to ensure smooth updates and prevent conflicts.

Conclusion

Micro Frontend Architecture presents a powerful approach to building modern, scalable, and maintainable web applications. By breaking down monolithic frontends into independent units, it fosters agility, promotes code reusability, and empowers development teams to work efficiently. While embracing Micro Frontend Architecture requires careful consideration and planning, it offers numerous benefits, including faster development cycles, improved scalability, and enhanced flexibility. By adhering to best practices and leveraging the right tools and frameworks, developers can unlock the full potential of this revolutionary architectural pattern.