Dagger 2 use in Android app development

1. Dagger 2

2. Dagger 2
Dagger 2 analyzes dependencies for you and generates code to help wire them
together.

3. WITHOUT DAGGER 2
Activities
Fragments
Views
Objects
API interface
(Retrofit)
Image Loader
(Picasso)
Shared Preference
Network client
Image disk cache

4. DAGGER USAGE
Components Object
Find object
@Inject
Take all fields with annotation, look in the component and find the object by type, and set the
field.

5. DAGGER USAGE
@Inject Picasso Picasso;
@ Inject Preference preference onject
// in oncreate function
getComponent().inject(this)
Take all fields with annotation, look in the component and find the object by type, and set the field.

6. ANNOTATIONS USED BY DAGGER 2
• @Module and @Provides
• @Inject
• @Components

7. MODULES & COMPONENTS
Activities
Fragments
Views
Objects
Network client
Shared Preferences
Application
Network module
Storage module
Application module
Application
component
.inject()

8. SCOPES
• @UserScope
• @Singleton
• @ActivityScope

9. CONSTRUCTOR INJECTION
@Provides
public StoreUserInfo provideStorUserInfo(NetworkApi
networkApi){
return new StoreUserInfo(networkApi);
}
public class MainActivity extends AppCompatActivity {
@Inject
StoreUserInfo storeUserInfo;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
((MyApplication) getApplication()).getComponent()
.inject(this);
}