Exploring Micro-Front-End Architecture in Flutter: Breaking Large Applications into Manageable Modules | by Sinnoor C | October 2024

Micro-front-end architecture involves dividing large applications into smaller parts that can be developed, tested, and maintained independently. This approach is ideal for complex projects because it allows teams to work on different features simultaneously without stepping on each other’s toes. This also means that different features can be updated and improved without risking the stability of the entire application.

In this example, we construct both a admin app and a client application for an e-commerce platform. Here’s how we can divide core functionality into independent modules and shared components to make development smoother and more scalable:

User authentication module:

• Manages login, registration, user profiles, and authentication (for example, token-based authentication).
• By keeping this separate, the administrator and client applications can use the same authentication logic without duplication.

Product catalog module:

• Manages product listing, filtering and search functionality.
• Any updates or new features (e.g. adding a new filter) can be easily applied to both client and administrator applications, avoiding code duplication.

Order management module:

• Covers everything related to orders, like creation, tracking, and status updates.
• Shared between the administrator (for order management) and the customer (for order display and tracking).

Notifications module:

• Manages push notifications, in-app alerts, and messaging, providing a consistent experience across both apps.

Shared widgets:

• Common UI components such as buttons, forms, and card layouts can be reused across both applications. This ensures a consistent appearance while saving development time.

Utility Classes:

• Utilities such as formatting functions (for example, date or number formatting), network services, and error handling are shared between the two applications to avoid duplication.

State management logic:

• Managing shared state (e.g., for authentication, products) helps maintain consistency between the two applications. Using a shared module for state allows you to effectively control application state without duplicating logic.

Layer is ideal for managing multiple Flutter and Dart projects in a single repository. He suggests:

• Packet isolation: Each module can have its own dependencies and logic, making development easier.
• Efficient workflows: Melos automates linking and testing, ensuring that updates are reflected smoothly across all dependent packages.
• Consistency: Shared components can be updated once and applied to both administrative applications and client applications.

Melos Documentation — Learn more about Melos and how it can help you manage Flutter monorepos.

For state management, I chose River Pod. It’s modern, flexible, and perfect for managing the shared state needed in large projects.

Why Riverpod?

• Scalability: Riverpod’s modular structure allows for easy scaling of state management as the application grows.
• Ease of testing: Unlike other solutions, Riverpod does not rely on the Flutter widget tree, making it easier to test business logic.
• Efficient asynchronous updates: Riverpod efficiently handles tasks like API calls and real-time update management, which is crucial for features like over-the-air product updates.

Riverpod integrates seamlessly with Go to routerwhich makes it easier to manage dynamic navigation in administration and client applications.

Advantages of Riverpod with GoRouter:

• State-aware navigation: GoRouter, combined with Riverpod, allows navigation to dynamically respond to application state changes. For example, the navigation path may change depending on whether a user is logged in or their role (administrator or customer).
• Simplified route management: GoRouter makes it easy to manage complex routes and deep links.

Below is a simple example of how you could structure your Flutter project using a micro-front-end architecture:

.
├── README.md
├── apps
│   ├── admin_app
│   │   ├── lib
│   │   │   └── main.dart
│   │   └── pubspec.yaml
│   └── customer_app
│       ├── lib
│       │   └── main.dart
│       └── pubspec.yaml
├── modules
│   ├── auth_module
│   │   ├── lib
│   │   │   └── auth_service.dart
│   │   └── pubspec.yaml
│   ├── product_module
│   │   ├── lib
│   │   │   └── product_service.dart
│   │   └── pubspec.yaml
│   ├── order_module
│   │   ├── lib
│   │   │   └── order_service.dart
│   │   └── pubspec.yaml
│   └── notification_module
│       ├── lib
│       │   └── notification_service.dart
│       └── pubspec.yaml
├── shared
│   ├── widgets
│   │   └── custom_button.dart
│   ├── utils
│   │   └── network_service.dart
│   └── pubspec.yaml
├── melos.yaml
└── pubspec.yaml

Adopting a front-end microarchitecture in Flutter can help solve scalability issues by breaking down a large application into smaller, manageable modules. Use tools like Layer for monorepo management, River Pod for scalable state management, and Go to router Managing dynamic navigation can make the development process smoother, more efficient, and easier to maintain.

Whether you’re a beginner or an experienced developer, adopting a modular approach can make a big difference in how you develop and manage complex applications. I hope this article gives you some insight into how you can apply these principles to your projects.

Have you tried splitting your Flutter apps into smaller modules? I’d love to hear about your experiences or answer any questions you have in the comments below!

For a more in-depth analysis and sample code on implementing a micro front-end architecture, check out my GitHub repository:

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