MVVM Architecture

Mvvm architecture in Kotlin & Android

MVVM stands for Model-View-ViewModel. It’s an architectural pattern that separates the user interface (UI) from the business logic of the application. Here’s a breakdown of each component:

• Model: Represents the data and business logic of the application. It holds the data and exposes methods to manipulate that data.
• View: Represents the UI components of the application. It observes changes in the ViewModel and updates accordingly. In Android, it's typically implemented as Activities or Fragments.
• ViewModel: Acts as an intermediary between the Model and the View. It holds the UI-related data that needs to be displayed and exposes methods for the View to interact with the data.

Here’s an example structure of an Android project following the MVVM architecture:

- app/
  - src/
    - main/
      - java/
        - com.example.myapp/
          - model/
            - UserRepository.java
            - User.java
          - view/
            - MainActivity.java
            - UserAdapter.java
          - viewmodel/
            - UserViewModel.java
          - di/ (Dependency Injection)
            - AppComponent.java
            - AppModule.java
            - ViewModelModule.java
          - util/
            - NetworkUtil.java
          - repository/
            - UserRepositoryImpl.java
          - data/
            - local/
              - UserDao.java
              - LocalDatabase.java
            - remote/
              - ApiService.java
          - di/
            - AppComponent.java
            - AppModule.java
            - NetworkModule.java
          - MyApplication.java
      - res/
        - layout/
          - activity_main.xml
          - item_user.xml

In this structure:

• model/: Contains data classes representing the entities in your application and repository interfaces.
• view/: Contains activities, fragments, adapters, and other UI-related classes.
• viewmodel/: Contains ViewModel classes that manage the UI-related data.
• di/: Contains classes for dependency injection using libraries like Dagger.
• util/: Contains utility classes.
• repository/: Contains repository classes that handle data operations.
• data/: Contains classes related to data management such as local and remote data sources.
• res/layout/: Contains XML layout files for UI components.

This structure separates concerns and makes the codebase more organized and easier to maintain.

Thanks for watching

Ranjan Gupta (Senior Android Engineer)