Dependency Injection Using Dagger 2 ->Improved and cleaned the code to provide optimized way of injecting dependencies.

Author: Ashwini Kumar

app/src/main/java/com/esoxjem/movieguide/ActivityScope.java

@@ -0,0 +1,11 @@
+package com.esoxjem.movieguide;
+
+import javax.inject.Scope;
+
+/**
+ * @author Ashwini Kumar.
+ */
+@Scope
+public @interface ActivityScope
+{
+}

app/src/main/java/com/esoxjem/movieguide/AppComponent.java

@@ -1,12 +1,12 @@
 package com.esoxjem.movieguide;
 
+import com.esoxjem.movieguide.details.DetailsComponent;
 import com.esoxjem.movieguide.details.DetailsModule;
-import com.esoxjem.movieguide.details.MovieDetailsFragment;
 import com.esoxjem.movieguide.favorites.FavoritesModule;
+import com.esoxjem.movieguide.listing.ListingComponent;
 import com.esoxjem.movieguide.listing.ListingModule;
-import com.esoxjem.movieguide.listing.MoviesListingFragment;
 import com.esoxjem.movieguide.network.NetworkModule;
-import com.esoxjem.movieguide.sorting.SortingDialogFragment;
+import com.esoxjem.movieguide.sorting.SortingComponent;
 import com.esoxjem.movieguide.sorting.SortingModule;
 
 import javax.inject.Singleton;
@@ -20,15 +20,12 @@
 @Component(modules = {
         AppModule.class,
         NetworkModule.class,
-        DetailsModule.class,
-        FavoritesModule.class,
-        ListingModule.class,
-        SortingModule.class})
+        FavoritesModule.class})
 public interface AppComponent
 {
-    MovieDetailsFragment inject(MovieDetailsFragment fragment);
+    DetailsComponent plus(DetailsModule detailsModule);
 
-    MoviesListingFragment inject(MoviesListingFragment fragment);
+    ListingComponent plus(ListingModule listingModule);
 
-    SortingDialogFragment inject(SortingDialogFragment fragment);
+    SortingComponent plus(SortingModule sortingModule);
 }

app/src/main/java/com/esoxjem/movieguide/BaseApplication.java

@@ -4,71 +4,43 @@
 import android.content.Context;
 import android.os.StrictMode;
 
-import com.esoxjem.movieguide.details.DetailsModule;
 import com.esoxjem.movieguide.favorites.FavoritesModule;
-import com.esoxjem.movieguide.listing.ListingModule;
 import com.esoxjem.movieguide.network.NetworkModule;
-import com.esoxjem.movieguide.sorting.SortingModule;
 
 /**
  * @author arun
  */
 public class BaseApplication extends Application
 {
-    private AppComponent component;
+    private AppComponent appComponent;
+
+    public static BaseApplication get(Context context)
+    {
+        return (BaseApplication) context.getApplicationContext();
+    }
 
     @Override
     public void onCreate()
     {
         super.onCreate();
         StrictMode.enableDefaults();
+        initAppComponent();
     }
 
-    public static AppComponent getAppComponent(Context context)
+    public AppComponent initAppComponent()
     {
-        BaseApplication app = (BaseApplication) context.getApplicationContext();
-        if (app.component == null)
-        {
-            app.component = DaggerAppComponent.builder()
-                    .appModule(app.getAppModule())
-                    .networkModule(app.getNetworkModule())
-                    .detailsModule(app.getDetailsModule())
-                    .favoritesModule(app.getFavoritesModule())
-                    .listingModule(app.getListingModule())
-                    .sortingModule(app.getSortingModule())
-                    .build();
-        }
-        return app.component;
-    }
+        appComponent = DaggerAppComponent.builder()
+                .appModule(new AppModule(this))
+                .networkModule(new NetworkModule())
+                .favoritesModule(new FavoritesModule())
+                .build();
 
-    private AppModule getAppModule()
-    {
-        return new AppModule(this);
-    }
-
-    private DetailsModule getDetailsModule()
-    {
-        return new DetailsModule();
-    }
-
-    private FavoritesModule getFavoritesModule()
-    {
-        return new FavoritesModule();
-    }
-
-    private ListingModule getListingModule()
-    {
-        return new ListingModule();
-    }
-
-    private SortingModule getSortingModule()
-    {
-        return new SortingModule();
+        return appComponent;
     }
 
-    private NetworkModule getNetworkModule()
+    public AppComponent getAppComponent()
     {
-        return new NetworkModule();
+        return appComponent;
     }
 
 }

app/src/main/java/com/esoxjem/movieguide/details/DetailsComponent.java

@@ -0,0 +1,15 @@
+package com.esoxjem.movieguide.details;
+
+import com.esoxjem.movieguide.ActivityScope;
+
+import dagger.Subcomponent;
+
+/**
+ * @author Ashwini Kumar.
+ */
+@ActivityScope
+@Subcomponent(modules = DetailsModule.class)
+public interface DetailsComponent
+{
+    void inject(MovieDetailsFragment movieDetailsFragment);
+}

app/src/main/java/com/esoxjem/movieguide/details/DetailsModule.java

@@ -1,29 +1,42 @@
 package com.esoxjem.movieguide.details;
 
-import com.esoxjem.movieguide.favorites.FavoritesModule;
+import com.esoxjem.movieguide.ActivityScope;
 import com.esoxjem.movieguide.favorites.IFavoritesInteractor;
-import com.esoxjem.movieguide.network.NetworkModule;
 import com.esoxjem.movieguide.network.RequestHandler;
 
-import javax.inject.Singleton;
-
 import dagger.Module;
 import dagger.Provides;
 
 /**
  * @author pulkitkumar
+ * @author Ashwini Kumar.
  */
-@Module(includes = {NetworkModule.class, FavoritesModule.class})
+@Module
 public class DetailsModule
 {
+    private MovieDetailsFragment movieDetailsFragment;
+
+    public DetailsModule(MovieDetailsFragment movieDetailsFragment)
+    {
+        this.movieDetailsFragment = movieDetailsFragment;
+    }
+
+    @Provides
+    @ActivityScope
+    MovieDetailsFragment provideMovieDetailsFragment()
+    {
+        return movieDetailsFragment;
+    }
+
     @Provides
-    @Singleton
+    @ActivityScope
     IMovieDetailsInteractor provideInteractor(RequestHandler requestHandler)
     {
         return new MovieDetailsInteractor(requestHandler);
     }
 
     @Provides
+    @ActivityScope
     IMovieDetailsPresenter providePresenter(IMovieDetailsInteractor detailsInteractor,
                                             IFavoritesInteractor favoritesInteractor)
     {

app/src/main/java/com/esoxjem/movieguide/details/MovieDetailsFragment.java

@@ -73,7 +73,7 @@ public void onCreate(Bundle savedInstanceState)
     {
         super.onCreate(savedInstanceState);
         setRetainInstance(true);
-        BaseApplication.getAppComponent(getContext()).inject(this);
+        BaseApplication.get(getContext()).getAppComponent().plus(new DetailsModule(this)).inject(this);
         movieDetailsPresenter.setView(this);
     }
 

app/src/main/java/com/esoxjem/movieguide/favorites/FavoritesModule.java

@@ -1,6 +1,6 @@
 package com.esoxjem.movieguide.favorites;
 
-import com.esoxjem.movieguide.AppModule;
+import android.content.Context;
 
 import javax.inject.Singleton;
 
@@ -9,8 +9,9 @@
 
 /**
  * @author pulkitkumar
+ * @author Ashwini Kumar.
  */
-@Module(includes = AppModule.class)
+@Module
 public class FavoritesModule
 {
     @Provides
@@ -19,4 +20,11 @@ IFavoritesInteractor provideFavouritesInteractor(FavoritesStore store)
     {
         return new FavoritesInteractor(store);
     }
+
+    @Provides
+    @Singleton
+    FavoritesStore provideFavoritesStore(Context context)
+    {
+        return new FavoritesStore(context);
+    }
 }

app/src/main/java/com/esoxjem/movieguide/favorites/FavoritesStore.java

@@ -4,6 +4,7 @@
 import android.content.SharedPreferences;
 import android.text.TextUtils;
 
+import com.esoxjem.movieguide.BaseApplication;
 import com.esoxjem.movieguide.Movie;
 import com.squareup.moshi.JsonAdapter;
 import com.squareup.moshi.Moshi;
@@ -13,8 +14,6 @@
 import java.util.List;
 import java.util.Map;
 
-import javax.inject.Inject;
-
 import javax.inject.Singleton;
 
 /**
@@ -27,10 +26,9 @@ public class FavoritesStore
     private static final String PREF_NAME = "FavoritesStore";
     private SharedPreferences pref;
 
-    @Inject
     public FavoritesStore(Context context)
     {
-        pref = context.getApplicationContext().getSharedPreferences(PREF_NAME, Context.MODE_PRIVATE);
+        pref = BaseApplication.get(context).getSharedPreferences(PREF_NAME, Context.MODE_PRIVATE);
     }
 
     public void setFavorite(Movie movie)

app/src/main/java/com/esoxjem/movieguide/listing/ListingComponent.java

@@ -0,0 +1,15 @@
+package com.esoxjem.movieguide.listing;
+
+import com.esoxjem.movieguide.ActivityScope;
+
+import dagger.Subcomponent;
+
+/**
+ * @author Ashwini Kumar.
+ */
+@ActivityScope
+@Subcomponent(modules = ListingModule.class)
+public interface ListingComponent
+{
+    void inject(MoviesListingFragment moviesListingFragment);
+}

app/src/main/java/com/esoxjem/movieguide/listing/ListingModule.java

@@ -1,25 +1,38 @@
 package com.esoxjem.movieguide.listing;
 
-import com.esoxjem.movieguide.network.NetworkModule;
-import com.esoxjem.movieguide.sorting.SortingModule;
-import com.esoxjem.movieguide.favorites.FavoritesModule;
+import android.content.Context;
+
+import com.esoxjem.movieguide.ActivityScope;
 import com.esoxjem.movieguide.favorites.IFavoritesInteractor;
 import com.esoxjem.movieguide.network.RequestHandler;
 import com.esoxjem.movieguide.sorting.SortingOptionStore;
 
-import javax.inject.Singleton;
-
 import dagger.Module;
 import dagger.Provides;
 
 /**
  * @author pulkitkumar
+ * @author Ashwini Kumar.
  */
-@Module(includes = {NetworkModule.class, SortingModule.class, FavoritesModule.class})
+@Module
 public class ListingModule
 {
+    private MoviesListingFragment moviesListingFragment;
+
+    public ListingModule(MoviesListingFragment moviesListingFragment)
+    {
+        this.moviesListingFragment = moviesListingFragment;
+    }
+
+    @Provides
+    @ActivityScope
+    MoviesListingFragment provideMoviesListingFragment()
+    {
+        return moviesListingFragment;
+    }
+
     @Provides
-    @Singleton
+    @ActivityScope
     IMoviesListingInteractor provideMovieListingInteractor(IFavoritesInteractor favoritesInteractor,
                                                            RequestHandler requestHandler,
                                                            SortingOptionStore sortingOptionStore)
@@ -28,8 +41,16 @@ IMoviesListingInteractor provideMovieListingInteractor(IFavoritesInteractor favo
     }
 
     @Provides
+    @ActivityScope
     IMoviesListingPresenter provideMovieListingPresenter(IMoviesListingInteractor interactor)
     {
         return new MoviesListingPresenter(interactor);
     }
+
+    @Provides
+    @ActivityScope
+    SortingOptionStore providesSortingOptionStore(Context context)
+    {
+        return new SortingOptionStore(context);
+    }
 }

app/src/main/java/com/esoxjem/movieguide/listing/MoviesListingFragment.java

@@ -51,7 +51,7 @@ public void onCreate(Bundle savedInstanceState)
         super.onCreate(savedInstanceState);
         setHasOptionsMenu(true);
         setRetainInstance(true);
-        BaseApplication.getAppComponent(getContext()).inject(this);
+        BaseApplication.get(getContext()).getAppComponent().plus(new ListingModule(this)).inject(this);
         moviesPresenter.setView(this);
     }
 

app/src/main/java/com/esoxjem/movieguide/sorting/SortingComponent.java

@@ -0,0 +1,15 @@
+package com.esoxjem.movieguide.sorting;
+
+import com.esoxjem.movieguide.ActivityScope;
+
+import dagger.Subcomponent;
+
+/**
+ * @author Ashwini Kumar.
+ */
+@ActivityScope
+@Subcomponent(modules = SortingModule.class)
+public interface SortingComponent
+{
+    void inject(SortingDialogFragment sortingDialogFragment);
+}

app/src/main/java/com/esoxjem/movieguide/sorting/SortingDialogFragment.java

@@ -39,7 +39,7 @@ public void onCreate(@Nullable Bundle savedInstanceState)
     {
         super.onCreate(savedInstanceState);
         setRetainInstance(true);
-        BaseApplication.getAppComponent(getContext()).inject(this);
+        BaseApplication.get(getContext()).getAppComponent().plus(new SortingModule(this)).inject(this);
         sortingDialogPresenter.setView(this);
     }
 

app/src/main/java/com/esoxjem/movieguide/sorting/SortingDialogInteractor.java

@@ -1,12 +1,15 @@
 package com.esoxjem.movieguide.sorting;
 
+import javax.inject.Inject;
+
 /**
  * @author arun
  */
 public class SortingDialogInteractor implements ISortingDialogInteractor
 {
     private SortingOptionStore sortingOptionStore;
 
+    @Inject
     public SortingDialogInteractor(SortingOptionStore store)
     {
         sortingOptionStore = store;