Flutter Architecture

Introduction

Choosing the right architecture is essential when developing mobile applications. It is important for building robust, maintainable, scalable apps. Flutter, Google's open-source UI software development toolkit, offers a variety of architectural patterns that help organise code, manage state, and promote separation of concerns.

This article will explore some popular Flutter architecture patterns. We will understand how they can benefit our app development process.

Flutter Architecture and Why Does it Matter?

Before delving into specific architecture patterns, it's essential to understand why architecture matters in Flutter app development. A well-designed architecture provides the following benefits.
 

• Code Organization: A clear and structured architecture ensures that code is organised. It also makes it easier for developers to understand and maintain the app.
   
• Maintainability: A well-architected app is easier to maintain and update as the project evolves. Which reduces the chances of introducing bugs or breaking existing functionality.
   
• Scalability: Scalability becomes more manageable with proper architecture. It allows the app to grow without compromising performance and stability.
   
• Testability: Architectures emphasising the separation of concerns make writing unit tests easier. It also helps in performing effective test-driven development (TDD).

The following are popular Flutter architecture patterns.

• 1. MVC (Model-View-Controller)
• 2. MVVM (Model-View-ViewModel)
• 3. Bloc Pattern
• 4. Provider Pattern

Now, let's explore these Flutter architecture patterns one by one.

MVC (Model-View-Controller)

MVC (Model-View-Controller) is one of the classic architectural patterns. This pattern is widely used in various frameworks, including Flutter. It separates the app into three components, let us learn each one by one.
 

• Model: Represents the data and business logic of the application.
   
• View: Handles the UI elements and their layout.
   
• Controller: Acts as an intermediary between the Model and View. It handles user input and updates the Model or View accordingly.

While MVC can provide a clear separation of concerns, there may be better choices for complex Flutter apps due to the tight coupling between the Controller and View.

MVVM (Model-View-ViewModel)

MVVM (Model-View-ViewModel) is another famous architecture that focuses on separating the UI logic from the business logic. It consists of three key components; let us learn each one by one.
 

• Model: Represents the data and business logic of the application.
   
• View: Handles the UI elements and their layout, similar to MVC.
   
• ViewModel: Acts as an intermediary between the Model and View, but unlike MVC, it does not have a direct reference to the View. Instead, it exposes data and commands that the View binds to.

MVVM encourages a more testable and maintainable codebase by reducing the dependency on the UI elements in the business logic.

Bloc Pattern

The Bloc (Business Logic Component) pattern is a state management architecture. This pattern aims to separate the UI from the business logic. It revolves around two main components; let us learn each one by one.
 

• Bloc: Contains the business logic and state management logic. It receives input events and emits corresponding states.
   
• UI: Represents the View in this architecture. It sends events to the Bloc and listens to state changes to update the UI accordingly.

The Bloc pattern is particularly useful for managing complex states and interactions in Flutter apps. It makes it easier to understand the application's behaviour.

Provider Pattern

The Provider pattern is a state management solution officially recommended by the Flutter team. It efficiently uses the InheritedWidget and ChangeNotifier to propagate state changes throughout the widget tree. To implement the provider pattern, we use Provider and Consumer. Provider and Consumer are classes and widgets, respectively. Alright! Let us learn about these one by one.
 

• Provider: Acts as a container for the app's state. It holds the data and notifies its dependents about any changes.
   
• Consumer: Represents the View in this pattern. It listens to changes from the Provider and rebuilds the UI accordingly.

The Provider pattern promotes a more straightforward and reactive approach to state management in Flutter apps.