تضمين التبعية يدويًا (طرق العرض)

class UserRepository(
   private val localDataSource: UserLocalDataSource,
   private val remoteDataSource: UserRemoteDataSource
) { ... }

class UserLocalDataSource { ... }
class UserRemoteDataSource(
   private val loginService: LoginRetrofitService
) { ... }

class UserLocalDataSource {
   public UserLocalDataSource() { }
   ...
}

class UserRemoteDataSource {

   private final Retrofit retrofit;

   public UserRemoteDataSource(Retrofit retrofit) {
       this.retrofit = retrofit;
   }

   ...
}

class UserRepository {

   private final UserLocalDataSource userLocalDataSource;
   private final UserRemoteDataSource userRemoteDataSource;

   public UserRepository(UserLocalDataSource userLocalDataSource, UserRemoteDataSource userRemoteDataSource) {
       this.userLocalDataSource = userLocalDataSource;
       this.userRemoteDataSource = userRemoteDataSource;
   }

   ...
}

class LoginActivity: Activity() {

   private lateinit var loginViewModel: LoginViewModel

   override fun onCreate(savedInstanceState: Bundle?) {
       super.onCreate(savedInstanceState)

       // In order to satisfy the dependencies of LoginViewModel, you have to also
       // satisfy the dependencies of all of its dependencies recursively.
       // First, create retrofit which is the dependency of UserRemoteDataSource
       val retrofit = Retrofit.Builder()
           .baseUrl("https://example.com")
           .build()
           .create(LoginService::class.java)

       // Then, satisfy the dependencies of UserRepository
       val remoteDataSource = UserRemoteDataSource(retrofit)
       val localDataSource = UserLocalDataSource()

       // Now you can create an instance of UserRepository that LoginViewModel needs
       val userRepository = UserRepository(localDataSource, remoteDataSource)

       // Lastly, create an instance of LoginViewModel with userRepository
       loginViewModel = LoginViewModel(userRepository)
   }
}

public class MainActivity extends Activity {

   private LoginViewModel loginViewModel;

   @Override
   protected void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.activity_main);

       // In order to satisfy the dependencies of LoginViewModel, you have to also
       // satisfy the dependencies of all of its dependencies recursively.
       // First, create retrofit which is the dependency of UserRemoteDataSource
       Retrofit retrofit = new Retrofit.Builder()
               .baseUrl("https://example.com")
               .build()
               .create(LoginService.class);

       // Then, satisfy the dependencies of UserRepository
       UserRemoteDataSource remoteDataSource = new UserRemoteDataSource(retrofit);
       UserLocalDataSource localDataSource = new UserLocalDataSource();

       // Now you can create an instance of UserRepository that LoginViewModel needs
       UserRepository userRepository = new UserRepository(localDataSource, remoteDataSource);

       // Lastly, create an instance of LoginViewModel with userRepository
       loginViewModel = new LoginViewModel(userRepository);
   }
}

// Container of objects shared across the whole app
class AppContainer {

   // Since you want to expose userRepository out of the container, you need to satisfy
   // its dependencies as you did before
   private val retrofit = Retrofit.Builder()
                           .baseUrl("https://example.com")
                           .build()
                           .create(LoginService::class.java)

   private val remoteDataSource = UserRemoteDataSource(retrofit)
   private val localDataSource = UserLocalDataSource()

   // userRepository is not private; it'll be exposed
   val userRepository = UserRepository(localDataSource, remoteDataSource)
}

// Container of objects shared across the whole app
public class AppContainer {

   // Since you want to expose userRepository out of the container, you need to satisfy
   // its dependencies as you did before
   private Retrofit retrofit = new Retrofit.Builder()
           .baseUrl("https://example.com")
           .build()
           .create(LoginService.class);

   private UserRemoteDataSource remoteDataSource = new UserRemoteDataSource(retrofit);
   private UserLocalDataSource localDataSource = new UserLocalDataSource();

   // userRepository is not private; it'll be exposed
   public UserRepository userRepository = new UserRepository(localDataSource, remoteDataSource);
}

// Custom Application class that needs to be specified
// in the AndroidManifest.xml file
class MyApplication : Application() {

   // Instance of AppContainer that will be used by all the Activities of the app
   val appContainer = AppContainer()
}

// Custom Application class that needs to be specified
// in the AndroidManifest.xml file
public class MyApplication extends Application {

   // Instance of AppContainer that will be used by all the Activities of the app
   public AppContainer appContainer = new AppContainer();
}

class LoginActivity: Activity() {

   private lateinit var loginViewModel: LoginViewModel

   override fun onCreate(savedInstanceState: Bundle?) {
       super.onCreate(savedInstanceState)

       // Gets userRepository from the instance of AppContainer in Application
       val appContainer = (application as MyApplication).appContainer
       loginViewModel = LoginViewModel(appContainer.userRepository)
   }
}

public class MainActivity extends Activity {

   private LoginViewModel loginViewModel;

   @Override
   protected void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.activity_main);

       // Gets userRepository from the instance of AppContainer in Application
       AppContainer appContainer = ((MyApplication) getApplication()).appContainer;
       loginViewModel = new LoginViewModel(appContainer.userRepository);
   }
}

// Definition of a Factory interface with a function to create objects of a type
interface Factory<T> {
   fun create(): T
}

// Factory for LoginViewModel.
// Since LoginViewModel depends on UserRepository, in order to create instances of
// LoginViewModel, you need an instance of UserRepository that you pass as a parameter.
class LoginViewModelFactory(private val userRepository: UserRepository) : Factory<LoginViewModel> {
   override fun create(): LoginViewModel {
       return LoginViewModel(userRepository)
   }
}

// Definition of a Factory interface with a function to create objects of a type
public interface Factory<T> {
   T create();
}

// Factory for LoginViewModel.
// Since LoginViewModel depends on UserRepository, in order to create instances of
// LoginViewModel, you need an instance of UserRepository that you pass as a parameter.
class LoginViewModelFactory implements Factory<LoginViewModel> {

   private final UserRepository userRepository;

   public LoginViewModelFactory(UserRepository userRepository) {
       this.userRepository = userRepository;
   }

   @Override
   public LoginViewModel create() {
       return new LoginViewModel(userRepository);
   }
}

// AppContainer can now provide instances of LoginViewModel with LoginViewModelFactory
class AppContainer {
   ...
   val userRepository = UserRepository(localDataSource, remoteDataSource)

   val loginViewModelFactory = LoginViewModelFactory(userRepository)
}

class LoginActivity: Activity() {

   private lateinit var loginViewModel: LoginViewModel

   override fun onCreate(savedInstanceState: Bundle?) {
       super.onCreate(savedInstanceState)

       // Gets LoginViewModelFactory from the application instance of AppContainer
       // to create a new LoginViewModel instance
       val appContainer = (application as MyApplication).appContainer
       loginViewModel = appContainer.loginViewModelFactory.create()
   }
}

// AppContainer can now provide instances of LoginViewModel with LoginViewModelFactory
public class AppContainer {
   ...

   public UserRepository userRepository = new UserRepository(localDataSource, remoteDataSource);

   public LoginViewModelFactory loginViewModelFactory = new LoginViewModelFactory(userRepository);
}

public class MainActivity extends Activity {

   private LoginViewModel loginViewModel;

   @Override
   protected void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.activity_main);

       // Gets LoginViewModelFactory from the application instance of AppContainer
       // to create a new LoginViewModel instance
       AppContainer appContainer = ((MyApplication) getApplication()).