Dagger 2 Android: Defeat the Dahaka

Presentation for Chicago Roboto 2018.

Github Demo : https://github.com/ragdroid/Dahaka
Medium Blogs : https://proandroiddev.com/dagger-2-android-defeat-the-dahaka-b1c542233efc

Transcript

1. Garima Jain @ragdroid “Defeat the Dahaka" Dagger 2 Android Version: @chicagoroboto
2. @ragdroid #chicagoroboto POP QUIZ • Dagger2? • Dagger Android • Prince of Persia
3. ABOUT THE TALK
4. Theme: Prince of Persia • Prince uses Dagger • Dagger can reverse time • Dahaka, (guardian of timeline) • Dahaka comes to kill the Prince.
5. Analogy • Prince = Us • Dagger = Dagger • Dahaka (Enemy) = Generated Code, Complexity
6. Analogy • Developer uses Dagger • Developer starts backtracking the generated code • Developer is chased by the Dahaka (complexity of generated code)
7. Agenda • Scopes - “Face of the Dahaka” • @Singleton Scopes • @Reusable Scopes • Custom Scopes • Component Dependencies - “Unleash the Beast” • Dependent Component • Subcomponent • Dagger Android - “Befriend the Beast”
8. Who? Assumption : Basic familiarity with Dagger
9. SCOPES “FACE OF THE DAHAKA”
10. Scope How long a scoped instance lives (javax.inject)
11. @Singleton Scope of dependency is throughout the application (javax.inject)
12. @ragdroid #chicagoroboto @SINGLETON EXAMPLE
13. AppComponent @Component(modules = [AppModule::class]) @Singleton interface AppComponent { fun application(): Application }
14. AppComponent @Component(modules = [AppModule::class]) @Singleton interface AppComponent { fun application(): Application }
15. @ragdroid #chicagoroboto CASE 1 DEPENDENCY WITH SCOPE
16. AppModule @Module class AppModule(val application: Application) { @Provides @Singleton fun provideApplication(): Application = application }
17. AppModule @Module class AppModule(val application: Application) { @Provides @Singleton fun provideApplication(): Application = application }
18. DaggerAppComponent @Generated public final class DaggerAppComponent implements AppComponent { private Provider<Application> applicationProvider; /** other code **/ private void initialize(final Builder builder) { this.applicationProvider = DoubleCheck.provider( AppModule_ApplicationFactory.create(builder.appModule)); } } (Generated)
19. Provider DaggerAppComponent @Generated public final class DaggerAppComponent implements AppComponent { private Provider<Application> applicationProvider; /** other code **/ private void initialize(final Builder builder) { this.applicationProvider = DoubleCheck.provider( AppModule_ApplicationFactory.create(builder.appModule)); } } (Generated)
20. Provider • For each @Provides annotation dagger generates a Provider * • Dagger’s Factory<T> interface is also a Provider • Dagger has various implementations of Providers: • SingleCheck • DoubleCheck (javax.inject) * Not for unscoped dependencies - Coming up
21. DaggerAppComponent @Generated public final class DaggerAppComponent implements AppComponent { private Provider<Application> applicationProvider; /** other code **/ private void initialize(final Builder builder) { this.applicationProvider = DoubleCheck.provider( AppModule_ApplicationFactory.create(builder.appModule)); } } (Generated)
22. DaggerAppComponent @Generated public final class DaggerAppComponent implements AppComponent { private Provider<Application> applicationProvider; /** other code **/ private void initialize(final Builder builder) { this.applicationProvider = DoubleCheck.provider( AppModule_ApplicationFactory.create(builder.appModule)); } } (Generated)
23. DaggerAppComponent @Generated public final class DaggerAppComponent implements AppComponent { private Provider<Application> applicationProvider; /** other code **/ private void initialize(final Builder builder) { this.applicationProvider = DoubleCheck.provider( AppModule_ApplicationFactory.create(builder.appModule)); } } (Generated)
24. DaggerAppComponent @Generated public final class DaggerAppComponent implements AppComponent { private Provider<Application> applicationProvider; /** other code **/ private void initialize(final Builder builder) { this.applicationProvider = DoubleCheck.provider( AppModule_ApplicationFactory.create(builder.appModule)); } } (Generated)
25. DoubleCheck Memoizes value using Double-Check idiom. (dagger.internal)
26. DoubleCheck Memoizes value using Double-Check idiom. public T get() {
 Object result = instance;
 if (result == UNINITIALIZED) {
 synchronized (this) {
 result = instance;
 if (result == UNINITIALIZED) {
 result = provider.get();
 
 Object currentInstance = instance; // other code
 instance = result;
 
 provider = null;
 }
 }
 }
 return (T) result;
 } (dagger.internal)
27. DoubleCheck Memoizes value using Double-Check idiom. public T get() {
 Object result = instance;
 if (result == UNINITIALIZED) {
 synchronized (this) {
 result = instance;
 if (result == UNINITIALIZED) {
 result = provider.get();
 
 Object currentInstance = instance; // other code
 instance = result;
 
 provider = null;
 }
 }
 }
 return (T) result;
 } (dagger.internal)
28. DoubleCheck Memoizes value using Double-Check idiom. public T get() {
 Object result = instance;
 if (result == UNINITIALIZED) {
 synchronized (this) {
 result = instance;
 if (result == UNINITIALIZED) {
 result = provider.get();
 
 Object currentInstance = instance; // other code
 instance = result;
 
 provider = null;
 }
 }
 }
 return (T) result;
 } (dagger.internal)
29. @ragdroid #chicagoroboto CASE 2 DEPENDENCY W/O SCOPE
30. AppModule @Module class AppModule(val application: Application) { @Provides //No @Singleton annotation fun provideApplication(): Application = application }
31. AppModule @Module class AppModule(val application: Application) { @Provides //No @Singleton annotation fun provideApplication(): Application = application }
32. DaggerAppComponent @Generated public final class DaggerAppComponent implements AppComponent { private Provider<Application> applicationProvider; /** other code **/ private void initialize(final Builder builder) { this.applicationProvider = ApplicationFactory.create(builder.appModule); } } (Generated)
33. DaggerAppComponent @Generated public final class DaggerAppComponent implements AppComponent { private Provider<Application> applicationProvider; /** other code **/ private void initialize(final Builder builder) { this.applicationProvider = ApplicationFactory.create(builder.appModule); } } (Generated)
34. DaggerAppComponent @Generated public final class DaggerAppComponent implements AppComponent { private Provider<Application> applicationProvider; /** other code **/ private void initialize(final Builder builder) { this.applicationProvider = ApplicationFactory.create(builder.appModule); } } (Generated)
35. DaggerAppComponent public final class DaggerAppComponent implements AppComponent { private AppModule appModule; @Override public Application application() { //No Factory Instance Creation return ApplicationFactory.proxyProviderApplication(appModule); } } (Generated) Since dagger 2.12
36. DaggerAppComponent public final class DaggerAppComponent implements AppComponent { private AppModule appModule; @Override public Application application() { //No Factory Instance Creation return ApplicationFactory.proxyProviderApplication(appModule); } } (Generated) Since dagger 2.12
37. DaggerAppComponent public final class DaggerAppComponent implements AppComponent { private AppModule appModule; @Override public Application application() { //No Factory Instance Creation return appModule.provideApplication(); } } (Generated) Since dagger 2.12
38. Take Aways • DONT “Scope All the Things!” • Scoping has overheads. • By-default no Scope. • Scope only when needed • Like for Heavy Objects
39. @ragdroid #chicagoroboto CASE 3 @REUSABLE
40. @Reusable • Limit the instantiation. • Use when Exact same instance not needed. • Can Have multiple sub-components caching different instances.
41. ReusableComponent 
 @Component(modules = [ReusableModule::class]) interface ReusableComponent { fun someObject(): SomeObject }
42. ReusableComponent 
 @Component(modules = [ReusableModule::class]) interface ReusableComponent { fun someObject(): SomeObject }
43. SomeObject @Reusable class SomeObject @Inject constructor()
44. DaggerReusableComponent @Generated public final class DaggerReusableComponent implements ReusableComponent { /** other code **/ Provider<SomeObject> someObjectProvider; private void initialize(final Builder builder) { this.someObjectProvider = SingleCheck.provider(SomeObject_Factory.create()); } } (Generated)
45. DaggerReusableComponent @Generated public final class DaggerReusableComponent implements ReusableComponent { /** other code **/ Provider<SomeObject> someObjectProvider; private void initialize(final Builder builder) { this.someObjectProvider = SingleCheck.provider(SomeObject_Factory.create()); } } (Generated)
46. DaggerReusableComponent @Generated public final class DaggerReusableComponent implements ReusableComponent { /** other code **/ Provider<SomeObject> someObjectProvider; private void initialize(final Builder builder) { this.someObjectProvider = SingleCheck.provider(SomeObject_Factory.create()); } } (Generated)
47. SingleCheck Memoizes value using simple lazy initialization and caching (dagger.internal)
48. Memoizes value using simple lazy initialization and caching public T get() {
 
 Provider<T> providerReference = provider;
 if (instance == UNINITIALIZED) {
 instance = providerReference.get();
 provider = null;
 }
 return (T) instance;
 } (dagger.internal) SingleCheck
49. Memoizes value using simple lazy initialization and caching public T get() {
 
 Provider<T> providerReference = provider;
 if (instance == UNINITIALIZED) {
 instance = providerReference.get();
 provider = null;
 }
 return (T) instance;
 } (dagger.internal) SingleCheck
50. @Singleton vs @Reusable vs No Scope • Heavy mutable object with State : @Singleton • Heavy immutable object / stateless : @Reusable • Not Heavy : No Scope •
51. @ragdroid #chicagoroboto GOD APP MODULE
52. @ragdroid #chicagoroboto App Module AppComponent @Module public class AppModule { private final Application application; @Provides @Si AppModule @Singleton @Component(modules = AppModule.class) @Singleton public interface AppComponent { Application application(); }
53. @ragdroid #chicagoroboto Big App Module AppComponent @Module public class AppModule { private final Application application; @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton AppModule @Singleton @Component(modules = AppModule.class) @Singleton public interface AppComponent { Application application(); }
54. @ragdroid #chicagoroboto AppComponent @Module public class AppModule { private final Application application; @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } } AppModule @Singleton Big App Module @Component(modules = AppModule.class) @Singleton public interface AppComponent { Application application(); }
55. @ragdroid #chicagoroboto AppComponent @Module public class AppModule { private final Application application; @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } } AppModule @Singleton God Module God App Module @Component(modules = AppModule.class) @Singleton public interface AppComponent { Application application(); }
56. @ragdroid #chicagoroboto God App Module How To Improve?
57. @ragdroid #chicagoroboto God App Module Splitting App Module
58. @ragdroid #chicagoroboto AppComponent @Module public class AppModule { private final Application application; @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } } @Singleton @Component(modules = AppModule.class) @Singleton public interface AppComponent { Application application(); } Splitting App Module ApiModule AppModule
59. @ragdroid #chicagoroboto Splitting App Module @Module public class AppModule { private final Application application; @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } } AppModule ApiModule AppComponent @Singleton @Component(modules = AppModule.class) @Singleton public interface AppComponent { Application application(); }
60. @ragdroid #chicagoroboto Splitting App Module AppComponent @Module public class AppModule { private final Application application; @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } @Provides @Singleton Application applicationProvider() { return application; } } AppModule @Singleton @Component(modules = AppModule.class) @Singleton public interface AppComponent { Application application(); } ApiModule @Component( modules = AppModule.class, ApiModule.class)
61. @ragdroid #chicagoroboto Splitting App Module
62. @ragdroid #chicagoroboto How to Improve? • Better Scope Management • More modularity • Custom Scopes : • @UserScope • @ActivityScope • @FragmentScope
63. @ragdroid #chicagoroboto Custom Scopes
64. @ragdroid #chicagoroboto Custom Scopes Multiple Components
65. Multiple Components 1. Dependent Components 2. Sub-Components
66. COMPONENT DEPENDENCIES
67. @ragdroid #chicagoroboto SUB COMPONENT VS DEPENDENT COMPONENT
68. AppComponent (@Singleton) UserComponent (@UserScope) UserComponent @UserScope Login Component @ActivityScope Home Component Items Component Login Component Home Component Items Component Fragments Fragments Launch pikachu Login Log-Out jigglypuff Application
69. AppComponent @Singleton DaggerAppComponent LoginComponent Sub Component @ActivityScope Dependent Component DaggerUserComponent • dependency HomeComponent ItemsComponent @UserScope
70. @ragdroid #chicagoroboto APP COMPONENT
71. @Singleton @Component(modules = arrayOf(AppModule::class, ApiModule::class)) interface AppComponent { fun loginBuilder(): LoginComponent.Builder } AppComponent
72. @Singleton @Component(modules = arrayOf(AppModule::class, ApiModule::class)) interface AppComponent { fun loginBuilder(): LoginComponent.Builder } AppComponent
73. @ragdroid #chicagoroboto DAHAKA APPLICATION
74. class DahakaApplication : Application() { override fun onCreate() { super.onCreate() appComponent = DaggerAppComponent .builder() .application(this) .build() } } DahakaApplication
75. class DahakaApplication : Application() { override fun onCreate() { super.onCreate() appComponent = DaggerAppComponent .builder() .application(this) .build() } } DahakaApplication
76. DEPENDENT COMPONENTS
77. @ragdroid #chicagoroboto USER COMPONENT
78. @Component(dependencies = arrayOf(AppComponent::class), modules = arrayOf(UserModule::class)) @UserScope interface UserComponent { } UserComponent
79. @Component(dependencies = arrayOf(AppComponent::class), modules = arrayOf(UserModule::class)) @UserScope interface UserComponent { } UserComponent
80. @ragdroid #chicagoroboto USER MANAGER
81. @Singleton class UserManager @Inject constructor(private val service: PokemonService) { var userComponent: UserComponent? = null private set public fun createUserSession(pokemon: Pokemon) { userComponent = DaggerUserComponent.builder() .appComponent(DahakaApplication.app.appComponent) .pokeMon(pokemon) .build() } … } UserManager
82. @Singleton class UserManager @Inject constructor(private val service: PokemonService) { var userComponent: UserComponent? = null private set public fun createUserSession(pokemon: Pokemon) { userComponent = DaggerUserComponent.builder() .appComponent(DahakaApplication.app.appComponent) .pokeMon(pokemon) .build() } … } UserManager
83. @Singleton class UserManager @Inject constructor(private val service: PokemonService) { var userComponent: UserComponent? = null private set public fun createUserSession(pokemon: Pokemon) { userComponent = DaggerUserComponent.builder() .appComponent(DahakaApplication.app.appComponent) .pokeMon(pokemon) .build() } … } UserManager
84. @ragdroid #chicagoroboto DAGGER USER COMPONENT (Generated)
85. public final class DaggerUserComponent implements UserComponent { … } DaggerUserComponent (Generated)
86. public final class DaggerUserComponent implements UserComponent { … } DaggerUserComponent (Generated)
87. SUB COMPONENTS
88. @ragdroid #chicagoroboto LOGIN SUBCOMPONENT
89. @ActivityScope @Subcomponent(modules = arrayOf(LoginModule::class)) interface LoginComponent { ... } LoginComponent
90. @ActivityScope @Subcomponent(modules = arrayOf(LoginModule::class)) interface LoginComponent { ... } LoginComponent
91. @ActivityScope @Subcomponent(modules = arrayOf(LoginModule::class)) interface LoginComponent { ... } LoginComponent
92. @ragdroid #chicagoroboto DAGGER APP COMPONENT (Generated)
93. public final class DaggerAppComponent implements AppComponent { private final class LoginComponentImpl implements LoginComponent { private LoginComponentImpl(LoginComponentBuilder builder) { assert builder != null; initialize(builder); } … } } DaggerAppComponent(Generated)
94. public final class DaggerAppComponent implements AppComponent { private final class LoginComponentImpl implements LoginComponent { private LoginComponentImpl(LoginComponentBuilder builder) { assert builder != null; initialize(builder); } … } } DaggerAppComponent(Generated)
95. public final class DaggerAppComponent implements AppComponent { private final class LoginComponentImpl implements LoginComponent { private LoginComponentImpl(LoginComponentBuilder builder) { assert builder != null; initialize(builder); } … } } DaggerAppComponent(Generated)
96. public final class DaggerAppComponent implements AppComponent { private final class LoginComponentImpl implements LoginComponent { private LoginComponentImpl(LoginComponentBuilder builder) { assert builder != null; initialize(builder); } … } } DaggerAppComponent(Generated)
97. @ragdroid #chicagoroboto SUB COMPONENT VS DEPENDENT COMPONENT
98. <<interface>> AppComponent fun schedulerProvider() @Singleton
99. DaggerAppComponent • schedulerProvider() : @Singleton • userManager : @Singleton LoginComponentImpl <<interface>> AppComponent fun schedulerProvider() @Singleton @ActivityScope
100. DaggerAppComponent • schedulerProvider() : @Singleton • userManager : @Singleton LoginComponentImpl <<interface>> AppComponent fun schedulerProvider() Sub Component LoginComponent accesses any dependencies of DaggerAppComponent directly as inner class can access outer class members. @Singleton @ActivityScope
101. DaggerUserComponent • schedulerProvider • pokemon DaggerAppComponent • schedulerProvider() : @Singleton • userManager : @Singleton LoginComponentImpl <<interface>> AppComponent fun schedulerProvider() HomeComponentImpl ItemsComponentImpl Dependent Component UserComponent accesses any dependencies of DaggerAppComponent via an interface of AppComponent. @Singleton @ActivityScope @UserScope @ActivityScope @ActivityScope Sub Component LoginComponent accesses any dependencies of DaggerAppComponent directly as inner class can access outer class members.
102. DaggerUserComponent • schedulerProvider • pokemon DaggerAppComponent • schedulerProvider() : @Singleton • userManager : @Singleton LoginComponentImpl <<interface>> AppComponent fun schedulerProvider() HomeComponentImpl ItemsComponentImpl @Singleton @ActivityScope @UserScope @ActivityScope @ActivityScope Sub Component LoginComponent accesses any dependencies of DaggerAppComponent directly as inner class can access outer class members. Dependent Component UserComponent accesses any dependencies of DaggerAppComponent via an interface of AppComponent.
103. @ragdroid #chicagoroboto Custom Scope Advantages • Dependency Lifecycle Management • Modularized code
104. @ragdroid #chicagoroboto Some Limitations • Repetitive Injection code • Class knows about it’s Injector
105. @ragdroid #chicagoroboto Some Limitations Dagger 2 Android
106. DAGGER 2 ANDROID “BEFRIEND THE BEAST”
107. @ragdroid #chicagoroboto DAHAKA APPLICATION
108. class DahakaApplication : Application(), HasActivityInjector { @Inject internal lateinit var activityInjector: DispatchingAndroidInjector<Activity> … override fun activityInjector(): AndroidInjector<Activity> { return activityInjector } … } DahakaApplication
109. class DahakaApplication : Application(), HasActivityInjector { @Inject internal lateinit var activityInjector: DispatchingAndroidInjector<Activity> … override fun activityInjector(): AndroidInjector<Activity> { return activityInjector } … } DahakaApplication
110. class DahakaApplication : Application(), HasActivityInjector { @Inject internal lateinit var activityInjector: DispatchingAndroidInjector<Activity> … override fun activityInjector(): AndroidInjector<Activity> { return activityInjector } … } DahakaApplication
111. HasActivityInjector class DahakaApplication : Application(), HasActivityInjector { @Inject internal lateinit var activityInjector: DispatchingAndroidInjector<Activity> … override fun activityInjector(): AndroidInjector<Activity> { return activityInjector } … } DahakaApplication
112. @ragdroid #chicagoroboto APP COMPONENT
113. @Singleton @Component(modules = arrayOf(AppModule::class, ApiModule::class, AppBindingModule::class, AndroidSupportInjectionModule::class)) interface AppComponent : AndroidInjector<DaggerApplication> { … } AppComponent
114. AppBindingModule @Singleton @Component(modules = arrayOf(AppModule::class, ApiModule::class, AppBindingModule::class, AndroidSupportInjectionModule::class)) interface AppComponent : AndroidInjector<DaggerApplication> { … } AppComponent
115. @Module abstract class AppBindingModule { @ContributesAndroidInjector(modules = arrayOf(LoginModule::class)) @ActivityScope internal abstract fun loginActivity(): LoginActivity } AppBindingModule
116. @ContributesAndroidInjector @Module abstract class AppBindingModule { @ContributesAndroidInjector(modules = arrayOf(LoginModule::class)) @ActivityScope internal abstract fun loginActivity(): LoginActivity } AppBindingModule
117. @Module abstract class AppBindingModule { @ContributesAndroidInjector(modules = arrayOf(LoginModule::class)) @ActivityScope internal abstract fun loginActivity(): LoginActivity } AppBindingModule No need to create LoginActivitySubcomponent class in the above case. @ContributesAndroidInjector AppBindingModule
118. @Module abstract class AppBindingModule { @ContributesAndroidInjector(modules = arrayOf(LoginModule::class)) @ActivityScope internal abstract fun loginActivity(): LoginActivity } AppBindingModule @Module abstract class LoginModule { @Binds abstract fun provideLoginPresenter(loginPresenter: LoginPresenter): LoginContract.Presenter } LoginModule
119. @Module(subcomponents = LoginActivitySubcomponent.class) public abstract class AppBindingModule_LoginActivity { @Binds @IntoMap @ActivityKey(LoginActivity.class) abstract AndroidInjector.Factory<? extends Activity> bindAndroidInjectorFactory( LoginActivitySubcomponent.Builder builder); @Subcomponent(modules = LoginModule.class) @ActivityScope public interface LoginActivitySubcomponent extends AndroidInjector<LoginActivity> { @Subcomponent.Builder abstract class Builder extends AndroidInjector.Builder<LoginActivity> {} } } LoginBindingModule(Generated)
120. @Module(subcomponents = LoginActivitySubcomponent.class) public abstract class AppBindingModule_LoginActivity { @Binds @IntoMap @ActivityKey(LoginActivity.class) abstract AndroidInjector.Factory<? extends Activity> bindAndroidInjectorFactory( LoginActivitySubcomponent.Builder builder); @Subcomponent(modules = LoginModule.class) @ActivityScope public interface LoginActivitySubcomponent extends AndroidInjector<LoginActivity> { @Subcomponent.Builder abstract class Builder extends AndroidInjector.Builder<LoginActivity> {} } } LoginBindingModule(Generated)
121. @Module(subcomponents = LoginActivitySubcomponent.class) public abstract class AppBindingModule_LoginActivity { @Binds @IntoMap @ActivityKey(LoginActivity.class) abstract AndroidInjector.Factory<? extends Activity> bindAndroidInjectorFactory( LoginActivitySubcomponent.Builder builder); @Subcomponent(modules = LoginModule.class) @ActivityScope public interface LoginActivitySubcomponent extends AndroidInjector<LoginActivity> { @Subcomponent.Builder abstract class Builder extends AndroidInjector.Builder<LoginActivity> {} } } LoginBindingModule(Generated)
122. @Module(subcomponents = LoginActivitySubcomponent.class) public abstract class AppBindingModule_LoginActivity { @Binds @IntoMap @ActivityKey(LoginActivity.class) abstract AndroidInjector.Factory<? extends Activity> bindAndroidInjectorFactory( LoginActivitySubcomponent.Builder builder); @Subcomponent(modules = LoginModule.class) @ActivityScope public interface LoginActivitySubcomponent extends AndroidInjector<LoginActivity> { @Subcomponent.Builder abstract class Builder extends AndroidInjector.Builder<LoginActivity> {} } } LoginBindingModule(Generated)
123. @Module(subcomponents = LoginActivitySubcomponent.class) public abstract class AppBindingModule_LoginActivity { @Binds @IntoMap @ActivityKey(LoginActivity.class) abstract AndroidInjector.Factory<? extends Activity> bindAndroidInjectorFactory( LoginActivitySubcomponent.Builder builder); @Subcomponent(modules = LoginModule.class) @ActivityScope public interface LoginActivitySubcomponent extends AndroidInjector<LoginActivity> { @Subcomponent.Builder abstract class Builder extends AndroidInjector.Builder<LoginActivity> {} } } LoginBindingModule(Generated)
124. @ragdroid #chicagoroboto LOGIN ACTIVITY
125. public class LoginActivity { @Inject LoginContract.Presenter presenter; @Override protected void onCreate(Bundle savedInstanceState) { AndroidInjection.inject(this); } } LoginActivity
126. AndroidInjection.inject(LoginActivity) LoginActivity public class LoginActivity { @Inject LoginContract.Presenter presenter; @Override protected void onCreate(Bundle savedInstanceState) { AndroidInjection.inject(this); } }
127. AndroidInjection.inject(LoginActivity) AndroidInjection.inje
128. AndroidInjection.inject(LoginActivity) AndroidInjection.inje AndroidInjection
129. AndroidInjection.inject(LoginActivity) AndroidInjection.inje AndroidInjection DaggerAppComponent
130. AndroidInjection.inject(LoginActivity) AndroidInjection.inje AndroidInjection DaggerAppComponent AppBindingModule_LoginActivity DispatchingAndroidInjector
131. AndroidInjection.inject(LoginActivity) AndroidInjection.inje AndroidInjection DaggerAppComponent AppBindingModule_LoginActivity DispatchingAndroidInjector
132. AndroidInjection.inject(LoginActivity) AndroidInjection.inje AndroidInjection DaggerAppComponent AppBindingModule_LoginActivity DispatchingAndroidInjector ApiModule_ProvideRetrofitFactory AppModule_ProviderSchedulerProviderFactory ApiModule_ProvidePokemonServiceFactory ApiModule_ProvideRetrofitFactory AppModule_ProviderSchedulerProviderFactory ApiModule_ProvidePokemonServiceFactory
133. @ragdroid #chicagoroboto BEFRIEND THE BEAST “You can not change your fate, No droid can.”
134. public interface HasActivityInjector { AndroidInjector<Activity> activityInjector(); } HasActivityInjector
135. HasActivityInjector • A simple interface. • Implementing class “Has” ActivityInjector. public interface HasActivityInjector { AndroidInjector<Activity> activityInjector(); }
136. HasActivityInjector <<interface>> HasActivityInjector fun activityInjector() : AndroidInjector<Activity>
137. HasActivityInjector <<interface>> HasActivityInjector fun activityInjector() : AndroidInjector<Activity> DahakaApplication • activityInjector : DispatchingAndroidInjector<Activity>
138. HasActivityInjector <<interface>> HasActivityInjector fun activityInjector() : AndroidInjector<Activity> DahakaApplication • activityInjector : DispatchingAndroidInjector<Activity> <<interface>> AndroidInjector<Activity> fun inject(Activity instance)
139. HasActivityInjector <<interface>> HasActivityInjector fun activityInjector() : AndroidInjector<Activity> DahakaApplication • activityInjector : DispatchingAndroidInjector<Activity> DispatchingAndroidInjector<Activity> • inject(Activity activity) • injectorFactories : Map <<interface>> AndroidInjector<Activity> fun inject(Activity instance)
140. DispatchingAndroidInjector Provider<LoginActivitySubcomponent.Builder> LoginActivity.class Class<Activity> Provider<Subcomponent.Builder> DispatchingAndroidInject<Activity> • gets the Subcomponent.Builder from injectorFactory. • creates an instance using Builder. • calls component.inject(instance) to perform injections. • Injects members for Android types : Activity, Fragment, etc • Has a Map<Class, Provider<Subcomponent.Builder>> injectorFactories.
141. AndroidInjection.inject(LoginActivity)
142. AndroidInjection.inject(LoginActivity) activity .getApplication() LoginActivity
143. AndroidInjection.inject(LoginActivity) activity .getApplication() LoginActivity application .activityInjector() DahakaApplication : HasActivityInjector
144. AndroidInjection.inject(LoginActivity) activity .getApplication() LoginActivity application .activityInjector() DahakaApplication : HasActivityInjector activityInjector .inject(activity) DispatchingAndroidInjector : AndroidInjector
145. AndroidInjection.inject(LoginActivity) activity .getApplication() LoginActivity application .activityInjector() DahakaApplication : HasActivityInjector activityInjector .inject(activity) DispatchingAndroidInjector : AndroidInjector
146. DispatchingAndroidInjector.inject(LoginActivity) injectorFactories .get(LoginActivity.class) DispatchingAndroidInjector : AndroidInjector
147. DispatchingAndroidInjector : AndroidInjector Factory<LoginActivity> : LoginSubcomponent.Builder injectorFactories .get(LoginActivity.class) DispatchingAndroidInjector.inject(LoginActivity) builder .build()
148. DispatchingAndroidInjector : AndroidInjector Factory<LoginActivity> : LoginSubcomponent.Builder component .inject(activity) LoginSubcomponent injectorFactories .get(LoginActivity.class) DispatchingAndroidInjector.inject(LoginActivity) builder .build()
149. DispatchingAndroidInjector : AndroidInjector builder .build() Factory<LoginActivity> : LoginSubcomponent.Builder component .inject(activity) LoginSubcomponent DispatchingAndroidInjector.inject(LoginActivity) injectorFactories .get(LoginActivity.class)
150. • DaggerApplication • DaggerActivity • DaggerBroadcastReceiver • DaggerContentProvider • DaggerFragment • DaggerIntentService • DaggerService Dagger Boilerplate classes
151. @ragdroid #chicagoroboto Dagger 2 Android = Dahaka • D • A • H • A • K • A Dagger Android HasActivityInjector AndroidInjection Keys AndroidInjector
152. @ragdroid #chicagoroboto Dagger 2 Android “You can not change your fate, No droid can” Let’s befriend the beast instead.
153. @ragdroid #chicagoroboto LOGIN ACTIVITY
154. AndroidInjection.inject(LoginActivity) LoginActivity public class LoginActivity { @Inject LoginContract.Presenter presenter; @Override protected void onCreate(Bundle savedInstanceState) { val appComponent = ((application as DahakaApplication) .appComponent) loginComponent = appComponent .loginBuilder() .loginActivity(this) .build() loginComponent.inject(this) } }
155. LoginActivity public class LoginActivity { @Inject LoginContract.Presenter presenter; @Override protected void onCreate(Bundle savedInstanceState) { AndroidInjection.inject(this); } }
156. What Next? • Dagger Documentation : https://google.github.io/dagger// • todo-mvp-dagger : Mike Nakhimovich (@friendlyMikhail ) https://github.com/googlesamples/android-architecture/tree/todo-mvp-dagger • Dagger Example https://github.com/ragdroid/Dahaka • Testing article https://android.jlelse.eu/testing-your-app-with-dagger-2-c91cdc0860fb • Dagger and the Dahaka Series : https://medium.com/@ragdroid
157. Acknowledgements • Dagger Recipies : Miroslaw Stanek (@froger_mcs) https://about.me/froger_mcs • todo-mvp-dagger : Mike Nakhimovich (@friendlyMikhail ) https://github.com/googlesamples/android-architecture/tree/todo-mvp-dagger • Android Dialogs : Mike Nakhimovich https://www.youtube.com/watch?v=KwRXQ6nT7jQ • Proof Reading : Ritesh Gupta (@_riteshhh) • Migrate to Kotlin : Ravindra Kumar (@ravidsrk)
158. Demo Code • Dahaka Demo : https://github.com/ragdroid/Dahaka • Branches : • dagger-android : Pokemon app using dagger-android (With Tests, Fragments) • dagger-android-dependent-comp-kotlin : dagger-android with Dependent Component • subcomponent : UserComponent as subcomponent • dependent-component-kotlin : UserComponent as dependent component
159. Other References • Theme : Prince of Persia https://en.wikipedia.org/wiki/Prince_of_Persia • Dahaka https://files.gamebanana.com/img/ico/sprays/dahaka.png • Dagger https://in.pinterest.com/pin/397442735844321339/ • Android http://www.pngmart.com/files/4/Android-PNG-Image.png
160. @ragdroid #chicagoroboto CUT SCENES
161. Dagger 2 Android “Defeat the Dahaka" Garima Jain @ragdroid
162. Dagger 2 Android “Defeat the Dahaka" Garima Jain @ragdroid
163. FUELED http://fueled.com/garima garima@fueled.com THANK YOU
164. FUELED http://fueled.com/garima garima@fueled.com Q & A @ragdroid