What are all the common design patterns used in flutter projects ?

Common Design Patterns in Flutter

Design patterns are reusable solutions to common problems.

Architectural Patterns

MVC (Model-View-Controller)

• Model: Data
• View: UI
• Controller: Logic
• Simple, good for small apps

MVP (Model-View-Presenter)

• Model: Data
• View: UI (passive)
• Presenter: Logic
• Better separation than MVC

MVVM (Model-View-ViewModel)

• Model: Data
• View: UI
• ViewModel: Logic with data binding
• Most popular in Flutter

Clean Architecture

• Domain, Data, Presentation layers
• Dependency injection
• Repository pattern
• Enterprise apps

Behavioral Patterns

Singleton

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class Logger {
  static final Logger _instance = Logger._internal();
  Logger._internal();
  factory Logger() => _instance;
}

Observer

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final valueNotifier = ValueNotifier<int>(0);
valueNotifier.addListener(() => print('Changed'));

Builder

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Class Custom {
  int a, b;
  Custom({required this.a, required this.b});
}

UI Patterns

• Widget composition: Build complex UIs from simple widgets
• State management: Provider, Riverpod, BLoC
• Navigation: Named routes, Go Router
• Responsive design: MediaQuery, LayoutBuilder

Best Practice: Choose patterns based on app complexity.