In the evolving world of web development, one concept gaining traction is micro frontends, a design approach that extends the microservice concept to the frontend world. Among the various frameworks that support this paradigm, Angular is a standout choice for many developers. In this article, we’ll delve into Angular micro frontends, their creation, and the role of module federation.
What is an MFE (Micro Frontend) in Angular?
An MFE, or Micro Frontend, is a design approach where a frontend app is decomposed into individual, semi-independent “micro” apps working seamlessly together. This architecture is like microservices but on the frontend side.
With Angular, a popular JavaScript framework developed by Google, you can create robust, scalable Micro Frontends. Each Micro Frontend in Angular is essentially an Angular application itself, but when combined, they form a complete application. This modularity offers many benefits, such as independent deployment, team autonomy, and the ability to write code in different frameworks.
Creating a Micro Frontend with Angular
Let’s now look at how we can create a micro frontend with Angular. The steps outlined below will guide you through the process:
1. Setting up the Environment: Before you start, make sure Node.js and Angular CLI are installed in your system.
2. Creating the Main App: Use Angular CLI to generate a new Angular application. This application will serve as the container for the micro frontends.
3. Generating Micro Frontends: Now, create individual micro frontend applications using the Angular CLI. Each micro frontend is a standalone Angular application.
4. Integrating Micro Frontends: Integrate these micro frontends into the main app. You can use tools like Module Federation Plugin (available with Webpack 5), which allows a JavaScript application to dynamically run code from another bundle/build.
Remember, each micro frontend should be designed and developed as an independent application, with its own testing and deployment pipeline. Also, each one should have a well-defined boundary and should be developed by an autonomous team.
Using Module Federation using Angular
Module Federation is a JavaScript architecture invented by the Webpack team. It allows a JavaScript application to dynamically run code from another bundle/build, offering the benefit of separating an application into smaller parts.
In the context of Angular and micro frontends, module federation simplifies the process of integrating separately built and deployed Micro Frontends into a host application. In a nutshell, it allows Angular applications (the micro frontends) to act as dynamically-loaded modules.
5. Managing Shared Libraries: Each micro frontend might use common libraries (like Angular itself or RxJS). To prevent each micro frontend from loading its own copy of these libraries, you can “share” these libraries using module federation. This way, only one copy of each shared library is loaded by the browser, reducing the total script size.
6. Routing: To give users the experience of a cohesive app, establish a global routing system in the container application. This routing system should handle navigation between micro frontends. Angular’s built-in router can handle this task efficiently.
7. Styling: To maintain a consistent look and feel across the application, use a shared style guide or a design system. You could also use CSS-in-JS libraries or Web Components to encapsulate styles in components.
8. Deployment: Each micro frontend should have its own CI/CD pipeline. This allows for independent updates, minimizing the risk of deployment.
By following these steps, you can create a scalable, flexible micro frontend application with Angular.
Which Framework is Best?
While Angular provides an excellent framework for building micro frontends, other options might be more suitable depending on the use case. Below are a few notable choices:
React: React is highly modular and component-based, making it a popular choice for micro frontends. It also boasts a large community and extensive libraries.
Vue.js: Vue.js is appreciated for its simplicity and lightweight nature, making it another great choice for micro frontends.
Svelte: Svelte is a newer option that compiles components to highly efficient imperative code that directly manipulates the DOM. It provides a simple and elegant solution for creating micro frontends.
Angular: Of course, as we’ve seen in this guide, Angular is also a superb choice, particularly for large applications with complex requirements. Its built-in tools and scalability make it ideal for micro frontend architecture.
In conclusion, there’s no “best” framework for micro frontends; it ultimately depends on your team’s expertise, project requirements, and the complexity of the application.
Conclusion
Angular micro frontends represent a significant shift in how we build large, complex web applications. By breaking down monolithic frontends into smaller, manageable parts, they enable code reuse, independent deployments, and language-agnostic development, bringing many of the benefits of microservices to frontend development.
While the adoption of micro frontends does bring challenges, particularly around integration and consistency, solutions such as module federation are helping to simplify these issues. As with any architectural decision, it’s essential to weigh these benefits and challenges against your unique project requirements.
It’s also worth noting that while we’ve focused on Angular in this article, micro frontends can be implemented with any modern frontend framework. Angular offers a powerful, feature-rich environment for building complex applications, but React, Vue.js, and Svelte are all equally viable choices, depending on your needs.
In the end, the micro frontend approach to software architecture is a powerful tool in the right circumstances, offering a pathway to scale and evolve large frontend codebases efficiently.
