Dagger 2 Android : Defeat the Dahaka

Presentation for Droidcon Berlin, 2017.

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

Transcript

1. “Defeat the Dahaka"
   Dagger 2 Android
   Garima Jain
   @ragdroid
   

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2. Garima Jain
   @ragdroid
   

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3. Garima Jain
   @ragdroid
   

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4. Garima Jain
   @ragdroid
   

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5. Garima Jain
   @ragdroid
   

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6. Garima Jain
   @ragdroid
   

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7. Garima Jain
   @ragdroid
   

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8. @ragdroid
   @droidconDE
   

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9. @ragdroid
   @droidconDE
   MVP
   Testing
   DataBinding
   Retrofit
   Dagger 2
   

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10. Garima Jain
    @ragdroid
    “Defeat the Dahaka"
    Dagger 2 Android
    

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11. @ragdroid
    @droidconDE
    POP QUIZ
    • Dagger2?
    • Dagger Android
    • Prince of Persia
    

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12. ABOUT THE TALK
    

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13. Theme: Prince of Persia
    • Prince uses Dagger
    • Dagger can reverse time
    • Dahaka, (guardian of timeline)
    • Dahaka comes to kill the Prince.
    

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14. Analogy
    • Prince = Us
    • Dagger = Dagger
    • Dahaka (Enemy) = Generated Code, Complexity
    

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15. Analogy
    • Developer uses Dagger
    • Developer starts backtracking the generated code
    • Developer is chased by the Dahaka (complexity of generated code)
    

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16. Agenda
    • Brief Introduction - “Codes of Time”
    • Scopes - “Face of the Dahaka”
    • @Singleton Scopes
    • @Reusable Scopes
    • Custom Scopes
    • Component Dependencies - “Unleash the Beast”
    • Demo App
    • Dependent Component
    • Subcomponent
    • Intermediate Concepts - “Defeat the Dahaka”
    • Dagger Android - “Befriend the Beast”
    

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17. Who?
    • Assumption : Basic familiarity with Dagger
    • Intermediate
    

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18. INTRODUCTION
    “CODES OF TIME”
    

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19. @ragdroid
    @droidconDE
    Droid of Asia
    

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20. @ragdroid
    @droidconDE
    public UserManager() {

    this.service = new PokemonService(); 

    }
    Droid of Asia
    

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21. @ragdroid
    @droidconDE
    Dependency Creation Disadvantages
    • Non-Testable
    • Non-Extendable
    

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22. @ragdroid
    @droidconDE
    Dagger 1
    

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23. @ragdroid
    @droidconDE
    Dagger 1 Advantages
    • Testable code
    • Modularized
    

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24. @ragdroid
    @droidconDE
    Dagger 1 Disadvantages
    • Reflection
    • Runtime Graph Composition
    • God Module with @Singleton
    • Difficult to use proguard
    

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25. @ragdroid
    @droidconDE
    Dagger 1 Disadvantages
    Dagger 2
    

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26. @ragdroid
    @droidconDE
    Dagger 2 Advantages
    • No Reflection
    • Compile-time Graph Composition
    • Traceable code
    • Better Scope management
    

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27. SCOPES
    “FACE OF THE DAHAKA”
    

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28. Scope
    • Annotation from javax.inject package
    • How long a scoped instance lives
    • What happens if :
    • No Scope specified?
    • Annotation is specified?
    

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29. @Singleton
    • Another annotation from javax.inject package
    • Scope of dependency is throughout the application
    • Two ways to re-use dependencies :
    • Annotate Provider methods
    • Annotate the Dependency class itself
    

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30. @ragdroid
    @droidconDE
    @SINGLETON
    EXAMPLE
    

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31. AppComponent
    @Component(modules = AppModule.class)
    @Singleton
    public interface AppComponent {
    Application application();
    }
    

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32. AppComponent
    @Component(modules = AppModule.class)
    @Singleton
    public interface AppComponent {
    Application application();
    }
    AppComponent
    

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33. @ragdroid
    @droidconDE
    CASE 1
    DEPENDENCY W/O SCOPE
    

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34. AppModule
    @Module
    public class AppModule {
    private final Application application;
    public AppModule(Application application) {
    this.application = application;
    }
    @Provides //No @Singleton annotation
    Application applicationProvider() {
    return application;
    }
    }
    

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35. @Module
    public class AppModule {
    private final Application application;
    public AppModule(Application application) {
    this.application = application;
    }
    @Provides //No @Singleton annotation
    Application applicationProvider() {
    return application;
    }
    }
    AppModule
    

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36. DaggerAppComponent
    @Generated
    public final class DaggerAppComponent implements AppComponent {
    private Provider applicationProvider;
    /** other code **/
    private void initialize(final Builder builder) {
    this.applicationProvider =
    AppModule_ApplicationFactory.create(builder.appModule);
    }
    }
    (Generated)
    

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37. DaggerAppComponent
    @Generated
    public final class DaggerAppComponent implements AppComponent {
    private Provider applicationProvider;
    /** other code **/
    private void initialize(final Builder builder) {
    this.applicationProvider =
    AppModule_ApplicationFactory.create(builder.appModule);
    }
    }
    (Generated)
    

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38. DaggerAppComponent
    @Generated
    public final class DaggerAppComponent implements AppComponent {
    private Provider applicationProvider;
    /** other code **/
    private void initialize(final Builder builder) {
    this.applicationProvider =
    AppModule_ApplicationFactory.create(builder.appModule);
    }
    }
    (Generated)
    

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39. @ragdroid
    @droidconDE
    CASE 2
    DEPENDENCY WITH SCOPE
    

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40. AppModule
    @Module
    public class AppModule {
    private final Application application;
    public AppModule(Application application) {
    this.application = application;
    }
    @Provides
    @Singleton
    Application applicationProvider() {
    return application;
    }
    }
    

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41. AppModule
    @Module
    public class AppModule {
    private final Application application;
    public AppModule(Application application) {
    this.application = application;
    }
    @Provides
    @Singleton
    Application applicationProvider() {
    return application;
    }
    }
    

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42. DaggerAppComponent
    @Generated
    public final class DaggerAppComponent implements AppComponent {
    private Provider applicationProvider;
    /** other code **/
    private void initialize(final Builder builder) {
    this.applicationProvider =
    DoubleCheck.provider(
    AppModule_ApplicationFactory.create(builder.appModule));
    }
    }
    (Generated)
    

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43. DaggerAppComponent
    @Generated
    public final class DaggerAppComponent implements AppComponent {
    private Provider applicationProvider;
    /** other code **/
    private void initialize(final Builder builder) {
    this.applicationProvider =
    DoubleCheck.provider(
    AppModule_ApplicationFactory.create(builder.appModule));
    }
    }
    (Generated)
    

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44. DaggerAppComponent
    @Generated
    public final class DaggerAppComponent implements AppComponent {
    private Provider applicationProvider;
    /** other code **/
    private void initialize(final Builder builder) {
    this.applicationProvider =
    DoubleCheck.provider(
    AppModule_ApplicationFactory.create(builder.appModule));
    }
    }
    (Generated)
    

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45. DaggerAppComponent
    @Generated
    public final class DaggerAppComponent implements AppComponent {
    private Provider applicationProvider;
    /** other code **/
    private void initialize(final Builder builder) {
    this.applicationProvider =
    DoubleCheck.provider(
    AppModule_ApplicationFactory.create(builder.appModule));
    }
    }
    (Generated)
    

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46. DoubleCheck
    Memoizes value using Double-Check idiom.
    (dagger.internal)
    

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47. 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)
    

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48. 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)
    

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49. 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)
    

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50. Take Aways
    • DONT “Scope All the Things!”
    • Scoping has overheads.
    • By-default no Scope.
    • Scope only when needed
    • Like for Heavy Mutable Objects
    

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51. @ragdroid
    @droidconDE
    @REUSABLE
    

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52. @Reusable
    • Limit the instantiation.
    • Use when Exact same instance not needed.
    • Not tied to any component or subcomponent.
    • Can Have multiple sub-components caching different instances.
    • Use for heavy immutable dependencies.
    

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53. ReusableComponent
    

    @Component(modules = ReusableModule.class)
    public interface ReusableComponent {
    SomeObject someObject();
    }
    

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54. ReusableComponent
    

    @Component(modules = ReusableModule.class)
    public interface ReusableComponent {
    SomeObject someObject();
    }
    

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55. SomeObject
    @Reusable
    public class SomeObject {
    @Inject
    public SomeObject() {
    }
    }
    

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56. DaggerReusableComponent
    @Generated
    public final class DaggerReusableComponent implements
    ReusableComponent {
    /** other code **/
    Provider someObjectProvider;
    private void initialize(final Builder builder) {
    this.someObjectProvider =
    SingleCheck.provider(SomeObject_Factory.create());
    }
    }
    (Generated)
    

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57. DaggerReusableComponent
    @Generated
    public final class DaggerReusableComponent implements
    ReusableComponent {
    /** other code **/
    Provider someObjectProvider;
    private void initialize(final Builder builder) {
    this.someObjectProvider =
    SingleCheck.provider(SomeObject_Factory.create());
    }
    }
    (Generated)
    

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58. DaggerReusableComponent
    @Generated
    public final class DaggerReusableComponent implements
    ReusableComponent {
    /** other code **/
    Provider someObjectProvider;
    private void initialize(final Builder builder) {
    this.someObjectProvider =
    SingleCheck.provider(SomeObject_Factory.create());
    }
    }
    (Generated)
    

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59. SingleCheck
    Memoizes value using simple lazy initialization and caching
    (dagger.internal)
    

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60. Memoizes value using simple lazy initialization and caching
    public T get() {

    

    Provider providerReference = provider;

    if (instance == UNINITIALIZED) {

    instance = providerReference.get();

    provider = null;

    }

    return (T) instance;

    }
    (dagger.internal)
    SingleCheck
    

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61. Memoizes value using simple lazy initialization
    public T get() {

    

    Provider providerReference = provider;

    if (instance == UNINITIALIZED) {

    instance = providerReference.get();

    provider = null;

    }

    return (T) instance;

    }
    (dagger.internal)
    SingleCheck
    

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62. @Singleton vs @Reusable
    • Heavy mutable object : @Singleton
    • Heavy immutable object : @Reusable
    •
    
    

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63. @ragdroid
    @droidconDE
    GOD APP MODULE
    

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64. @ragdroid
    @droidconDE
    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();
    }
    

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65. @ragdroid
    @droidconDE
    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();
    }
    

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66. @ragdroid
    @droidconDE
    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();
    }
    

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67. @ragdroid
    @droidconDE
    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();
    }
    

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68. @ragdroid
    @droidconDE
    God App Module
    How To Improve?
    
    

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69. @ragdroid
    @droidconDE
    God App Module
    Splitting App Module
    
    

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70. @ragdroid
    @droidconDE
    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
    

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71. @ragdroid
    @droidconDE
    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();
    }
    

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72. @ragdroid
    @droidconDE
    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)
    

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73. @ragdroid
    @droidconDE
    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
    @Component(
    modules = AppModule.class,
    ApiModule.class)
    OR
    AppComponent
    

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74. @ragdroid
    @droidconDE
    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
    @Component(
    modules = AppModule.class,
    ApiModule.class)
    @Module(
    includes = ApiModule.class)
    AppModule
    OR
    AppComponent
    

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75. @ragdroid
    @droidconDE
    Splitting App Module
    
    

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76. @ragdroid
    @droidconDE
    How to Improve?
    • Better Scope Management
    • More modularity
    • Custom Scopes :
    • @UserScope
    • @ActivityScope
    • @FragmentScope
    

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77. @ragdroid
    @droidconDE
    Custom Scopes
    

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78. @ragdroid
    @droidconDE
    Custom Scopes
    Multiple Components
    

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79. Multiple Components
    1. Dependent Components
    2. Sub-Components
    

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80. COMPONENT
    DEPENDENCIES
    

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81. @ragdroid
    @droidconDE
    POKEMON APP
    

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82. AppComponent (@Singleton)
    UserComponent
    (@UserScope)
    UserComponent
    @UserScope
    Login
    Component
    @ActivityScope
    Home
    Component
    Items
    Component
    Login
    Component
    Home
    Component
    Items
    Component
    Fragments Fragments
    Application
    

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83. AppComponent (@Singleton)
    UserComponent
    (@UserScope)
    UserComponent
    @UserScope
    Login
    Component
    @ActivityScope
    Home
    Component
    Items
    Component
    Login
    Component
    Home
    Component
    Items
    Component
    Fragments Fragments
    Launch
    Application
    

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84. AppComponent (@Singleton)
    UserComponent
    (@UserScope)
    UserComponent
    @UserScope
    Login
    Component
    @ActivityScope
    Home
    Component
    Items
    Component
    Login
    Component
    Home
    Component
    Items
    Component
    Fragments Fragments
    Launch
    pikachu Login
    Application
    

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85. AppComponent (@Singleton)
    UserComponent
    (@UserScope)
    UserComponent
    @UserScope
    Login
    Component
    @ActivityScope
    Home
    Component
    Items
    Component
    Login
    Component
    Home
    Component
    Items
    Component
    Fragments Fragments
    Launch
    pikachu Login
    Inventory
    Application
    

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86. 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
    Inventory
    Application
    

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87. 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
    Inventory
    Application
    

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88. 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
    Inventory
    Inventory
    Application
    

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89. Pokemon App
    

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90. @ragdroid
    @droidconDE
    SUB COMPONENT
    VS
    DEPENDENT COMPONENT
    

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91. <>
    AppComponent
    schedulerProvider
    @Singleton
    

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92. AppComponentImpl
    • schedulerProvider() : @Singleton
    • userManager : @Singleton
    LoginComponentImpl
    <>
    AppComponent
    schedulerProvider
    Sub Component
    @Singleton
    @ActivityScope
    

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93. UserComponentImpl
    • schedulerProvider
    • pokemon
    AppComponentImpl
    • schedulerProvider() : @Singleton
    • userManager : @Singleton
    LoginComponentImpl
    <>
    AppComponent
    schedulerProvider
    HomeComponentImpl
    ItemsComponentImpl
    Dependent Component
    Sub Component
    @Singleton
    @ActivityScope
    @UserScope
    @ActivityScope
    @ActivityScope
    

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94. UserComponentImpl
    • schedulerProvider
    • pokemon
    AppComponentImpl
    • schedulerProvider() : @Singleton
    • userManager : @Singleton
    LoginComponentImpl
    <>
    AppComponent
    schedulerProvider
    HomeComponentImpl
    ItemsComponentImpl
    Dependent Component
    Sub Component
    @Singleton
    @ActivityScope
    @UserScope
    @ActivityScope
    @ActivityScope
    

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95. @ragdroid
    @droidconDE
    APP COMPONENT
    

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96. @Singleton
    @Component(modules = arrayOf(AppModule::class, ApiModule::class))
    interface AppComponent {
    fun loginBuilder(): LoginComponent.Builder
    fun schedulerProvider(): BaseSchedulerProvider
    }
    AppComponent
    

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97. @Singleton
    @Component(modules = arrayOf(AppModule::class, ApiModule::class))
    interface AppComponent {
    fun loginBuilder(): LoginComponent.Builder
    fun schedulerProvider(): BaseSchedulerProvider
    }
    AppComponent
    

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98. @Singleton
    @Component(modules = arrayOf(AppModule::class, ApiModule::class))
    interface AppComponent {
    fun loginBuilder(): LoginComponent.Builder
    fun schedulerProvider(): BaseSchedulerProvider
    }
    AppComponent
    

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99. @ragdroid
    @droidconDE
    DAHAKA
    APPLICATION
    

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100. class DahakaApplication : Application() {
     override fun onCreate() {
     super.onCreate()
     appComponent = DaggerAppComponent
     .builder()
     .application(this)
     .build()
     }
     }
     DahakaApplication
     

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101. class DahakaApplication : Application() {
     override fun onCreate() {
     super.onCreate()
     appComponent = DaggerAppComponent
     .builder()
     .application(this)
     .build()
     }
     }
     DahakaApplication
     

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102. DEPENDENT
     COMPONENTS
     

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103. @ragdroid
     @droidconDE
     USER
     COMPONENT
     

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104. @Component(dependencies = arrayOf(AppComponent::class),
     modules = arrayOf(UserModule::class))
     @UserScope
     interface UserComponent {
     @Component.Builder
     interface Builder {
     @BindsInstance
     fun pokeMon(pokemon: Pokemon): Builder
     …
     }
     }
     UserComponent
     

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105. @Component(dependencies = arrayOf(AppComponent::class),
     modules = arrayOf(UserModule::class))
     @UserScope
     interface UserComponent {
     @Component.Builder
     interface Builder {
     @BindsInstance
     fun pokeMon(pokemon: Pokemon): Builder
     …
     }
     }
     UserComponent
     

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106. @Component(dependencies = arrayOf(AppComponent::class),
     modules = arrayOf(UserModule::class))
     @UserScope
     interface UserComponent {
     @Component.Builder
     interface Builder {
     @BindsInstance
     fun pokeMon(pokemon: Pokemon): Builder
     …
     }
     }
     UserComponent
     

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107. Binding Pokemon
     • Two ways of Providing / Binding Pokemon to graph
     1. UserModule Constructor
     2. @Component.Builder with @BindsInstance
     

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108. 

     @Module

     public abstract class UserModule {

     

     private final Pokemon pokemon;

     

     public UserModule(Pokemon pokemon) {

     this.pokemon = pokemon;

     }

     

     @Provides

     @UserScope

     public Pokemon providePokemon() {

     return pokemon;

     }

     

     }

     UserModule Constructor
     

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109. 

     @Module

     public abstract class UserModule {

     

     private final Pokemon pokemon;

     

     public UserModule(Pokemon pokemon) {

     this.pokemon = pokemon;

     }

     

     @Provides

     @UserScope

     public Pokemon providePokemon() {

     return pokemon;

     }

     

     }

     UserModule Constructor
     

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110. 

     @Module

     public abstract class UserModule {

     

     private final Pokemon pokemon;

     

     public UserModule(Pokemon pokemon) {

     this.pokemon = pokemon;

     }

     

     @Provides

     @UserScope

     public Pokemon providePokemon() {

     return pokemon;

     }

     

     }

     UserModule Constructor
     

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111. @Component(dependencies = arrayOf(AppComponent::class),
     modules = arrayOf(UserModule::class))
     @UserScope
     interface UserComponent {
     @Component.Builder
     interface Builder {
     @BindsInstance
     fun pokeMon(pokemon: Pokemon): Builder
     …
     }
     }
     User Component @Component.Builder
     

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112. @Component(dependencies = arrayOf(AppComponent::class),
     modules = arrayOf(UserModule::class))
     @UserScope
     interface UserComponent {
     @Component.Builder
     interface Builder {
     @BindsInstance
     fun pokeMon(pokemon: Pokemon): Builder
     …
     }
     }
     UserComponent @BindsInstance
     

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113. @ragdroid
     @droidconDE
     USER
     MANAGER
     

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114. @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
     

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115. @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
     

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116. @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
     

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117. @ragdroid
     @droidconDE
     DAGGER
     USER COMPONENT
     (Generated)
     

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118. public final class DaggerUserComponent implements UserComponent {
     private Provider schedulerProvider;
     private void initialize(final Builder builder) {
     this.schedulerProvider =
     new AppComponent_schedulerProvider(builder.appComponent);
     …
     }
     private static class AppComponent_schedulerProvider
     implements Provider {
     private final AppComponent appComponent;
     @Override
     public BaseSchedulerProvider get() {
     return appComponent.schedulerProvider();
     }
     …
     }
     }
     DaggerUserComponent (Generated)
     

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119. public final class DaggerUserComponent implements UserComponent {
     private Provider schedulerProvider;
     private void initialize(final Builder builder) {
     this.schedulerProvider =
     new AppComponent_schedulerProvider(builder.appComponent);
     …
     }
     private static class AppComponent_schedulerProvider
     implements Provider {
     private final AppComponent appComponent;
     @Override
     public BaseSchedulerProvider get() {
     return appComponent.schedulerProvider();
     }
     …
     }
     }
     DaggerUserComponent (Generated)
     

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120. public final class DaggerUserComponent implements UserComponent {
     private Provider schedulerProvider;
     private void initialize(final Builder builder) {
     this.schedulerProvider =
     new AppComponent_schedulerProvider(builder.appComponent);
     …
     }
     private static class AppComponent_schedulerProvider
     implements Provider {
     private final AppComponent appComponent;
     @Override
     public BaseSchedulerProvider get() {
     return appComponent.schedulerProvider();
     }
     …
     }
     }
     DaggerUserComponent (Generated)
     

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121. public final class DaggerUserComponent implements UserComponent {
     private Provider schedulerProvider;
     private void initialize(final Builder builder) {
     this.schedulerProvider =
     new AppComponent_schedulerProvider(builder.appComponent);
     …
     }
     private static class AppComponent_schedulerProvider
     implements Provider {
     private final AppComponent appComponent;
     @Override
     public BaseSchedulerProvider get() {
     return appComponent.schedulerProvider();
     }
     …
     }
     }
     DaggerUserComponent (Generated)
     

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122. public final class DaggerUserComponent implements UserComponent {
     private Provider schedulerProvider;
     private void initialize(final Builder builder) {
     this.schedulerProvider =
     new AppComponent_schedulerProvider(builder.appComponent);
     …
     }
     private static class AppComponent_schedulerProvider
     implements Provider {
     private final AppComponent appComponent;
     @Override
     public BaseSchedulerProvider get() {
     return appComponent.schedulerProvider();
     }
     …
     }
     }
     DaggerUserComponent (Generated)
     

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123. public final class DaggerUserComponent implements UserComponent {
     private Provider schedulerProvider;
     private void initialize(final Builder builder) {
     this.schedulerProvider =
     new AppComponent_schedulerProvider(builder.appComponent);
     …
     }
     private static class AppComponent_schedulerProvider
     implements Provider {
     private final AppComponent appComponent;
     @Override
     public BaseSchedulerProvider get() {
     return appComponent.schedulerProvider();
     }
     …
     }
     }
     DaggerUserComponent (Generated)
     

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124. SUB
     COMPONENTS
     

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125. @ragdroid
     @droidconDE
     LOGIN
     SUBCOMPONENT
     

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126. @ActivityScope
     @Subcomponent(modules = arrayOf(LoginModule::class))
     interface LoginComponent {
     @Subcomponent.Builder
     interface Builder {
     @BindsInstance
     fun loginActivity(loginActivity: LoginActivity): Builder
     }
     }
     LoginComponent
     

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127. @ActivityScope
     @Subcomponent(modules = arrayOf(LoginModule::class))
     interface LoginComponent {
     @Subcomponent.Builder
     interface Builder {
     @BindsInstance
     fun loginActivity(loginActivity: LoginActivity): Builder
     }
     }
     LoginComponent
     

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128. @ActivityScope
     @Subcomponent(modules = arrayOf(LoginModule::class))
     interface LoginComponent {
     @Subcomponent.Builder
     interface Builder {
     @BindsInstance
     fun loginActivity(loginActivity: LoginActivity): Builder
     }
     }
     LoginComponent
     

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129. @ActivityScope
     @Subcomponent(modules = arrayOf(LoginModule::class))
     interface LoginComponent {
     @Subcomponent.Builder
     interface Builder {
     @BindsInstance
     fun loginActivity(loginActivity: LoginActivity): Builder
     }
     }
     LoginComponent
     

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130. @ActivityScope
     @Subcomponent(modules = arrayOf(LoginModule::class))
     interface LoginComponent {
     @Subcomponent.Builder
     interface Builder {
     @BindsInstance
     fun loginActivity(loginActivity: LoginActivity): Builder
     }
     }
     LoginComponent
     

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131. @ragdroid
     @droidconDE
     LOGIN
     ACTIVITY
     

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132. class LoginActivity {
     private lateinit var loginComponent: LoginComponent
     override fun initDagger(appComponent: AppComponent) {
     loginComponent = appComponent
     .loginBuilder()
     .loginActivity(this)
     .build()
     }
     …
     }
     LoginActivity
     

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133. class LoginActivity {
     private lateinit var loginComponent: LoginComponent
     override fun initDagger(appComponent: AppComponent) {
     loginComponent = appComponent
     .loginBuilder()
     .loginActivity(this)
     .build()
     }
     …
     }
     LoginActivity
     

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134. @ragdroid
     @droidconDE
     DAGGER
     APP COMPONENT
     (Generated)
     

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135. public final class DaggerAppComponent implements AppComponent {
     this.loginBuilderProvider =
     new Factory() {
     @Override
     public LoginComponent.Builder get() {
     return new LoginComponentBuilder();
     }
     };
     }
     private final class LoginComponentBuilder implements LoginComponent.Builder {
     …
     }
     private final class LoginComponentImpl implements LoginComponent {
     private LoginComponentImpl(LoginComponentBuilder builder) {
     assert builder != null;
     initialize(builder);
     }
     …
     }
     }
     DaggerAppComponent (Generated)
     

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136. public final class DaggerAppComponent implements AppComponent {
     this.loginBuilderProvider =
     new Factory() {
     @Override
     public LoginComponent.Builder get() {
     return new LoginComponentBuilder();
     }
     };
     }
     private final class LoginComponentBuilder implements LoginComponent.Builder {
     …
     }
     private final class LoginComponentImpl implements LoginComponent {
     private LoginComponentImpl(LoginComponentBuilder builder) {
     assert builder != null;
     initialize(builder);
     }
     …
     }
     }
     DaggerAppComponent (Generated)
     

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137. public final class DaggerAppComponent implements AppComponent {
     this.loginBuilderProvider =
     new Factory() {
     @Override
     public LoginComponent.Builder get() {
     return new LoginComponentBuilder();
     }
     };
     }
     private final class LoginComponentBuilder implements LoginComponent.Builder {
     …
     }
     private final class LoginComponentImpl implements LoginComponent {
     private LoginComponentImpl(LoginComponentBuilder builder) {
     assert builder != null;
     initialize(builder);
     }
     …
     }
     }
     DaggerAppComponent (Generated)
     

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138. public final class DaggerAppComponent implements AppComponent {
     this.loginBuilderProvider =
     new Factory() {
     @Override
     public LoginComponent.Builder get() {
     return new LoginComponentBuilder();
     }
     };
     }
     private final class LoginComponentBuilder implements LoginComponent.Builder {
     …
     }
     private final class LoginComponentImpl implements LoginComponent {
     private LoginComponentImpl(LoginComponentBuilder builder) {
     assert builder != null;
     initialize(builder);
     }
     …
     }
     }
     DaggerAppComponent (Generated)
     

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139. public final class DaggerAppComponent implements AppComponent {
     this.loginBuilderProvider =
     new Factory() {
     @Override
     public LoginComponent.Builder get() {
     return new LoginComponentBuilder();
     }
     };
     }
     private final class LoginComponentBuilder implements LoginComponent.Builder {
     …
     }
     private final class LoginComponentImpl implements LoginComponent {
     private LoginComponentImpl(LoginComponentBuilder builder) {
     assert builder != null;
     initialize(builder);
     }
     …
     }
     }
     DaggerAppComponent (Generated)
     

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140. public final class DaggerAppComponent implements AppComponent {
     this.loginBuilderProvider =
     new Factory() {
     @Override
     public LoginComponent.Builder get() {
     return new LoginComponentBuilder();
     }
     };
     }
     private final class LoginComponentBuilder implements LoginComponent.Builder {
     …
     }
     private final class LoginComponentImpl implements LoginComponent {
     private LoginComponentImpl(LoginComponentBuilder builder) {
     assert builder != null;
     initialize(builder);
     }
     …
     }
     }
     DaggerAppComponent (Generated)
     

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141. public final class DaggerAppComponent implements AppComponent {
     this.loginBuilderProvider =
     new Factory() {
     @Override
     public LoginComponent.Builder get() {
     return new LoginComponentBuilder();
     }
     };
     }
     private final class LoginComponentBuilder implements LoginComponent.Builder {
     …
     }
     private final class LoginComponentImpl implements LoginComponent {
     private LoginComponentImpl(LoginComponentBuilder builder) {
     assert builder != null;
     initialize(builder);
     }
     …
     }
     }
     DaggerAppComponent (Generated)
     

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142. @ragdroid
     @droidconDE
     SUB COMPONENT
     VS
     DEPENDENT COMPONENT
     

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143. <>
     AppComponent
     fun schedulerProvider()
     @Singleton
     

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144. DaggerAppComponent
     • schedulerProvider() : @Singleton
     • userManager : @Singleton
     LoginComponentImpl
     <>
     AppComponent
     fun schedulerProvider()
     @Singleton
     @ActivityScope
     

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145. DaggerAppComponent
     • schedulerProvider() : @Singleton
     • userManager : @Singleton
     LoginComponentImpl
     <>
     AppComponent
     fun schedulerProvider()
     Sub Component
     LoginComponent accesses any dependencies
     of DaggerAppComponent directly as
     inner class can access outer class members.
     @Singleton
     @ActivityScope
     

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146. DaggerUserComponent
     • schedulerProvider
     • pokemon
     DaggerAppComponent
     • schedulerProvider() : @Singleton
     • userManager : @Singleton
     LoginComponentImpl
     <>
     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.
     

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147. DaggerUserComponent
     • schedulerProvider
     • pokemon
     DaggerAppComponent
     • schedulerProvider() : @Singleton
     • userManager : @Singleton
     LoginComponentImpl
     <>
     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.
     

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148. @ragdroid
     @droidconDE
     Custom Scope Advantages
     • Dependency Lifecycle Management
     • Modularized code
     

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149. @ragdroid
     @droidconDE
     Some Limitations
     • Repetitive Injection code
     • Class knows about it’s Injector
     

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150. @ragdroid
     @droidconDE
     Some Limitations
     Dagger 2 Android
     

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151. INTERMEDIATE CONCEPTS
     “DEFEAT THE DAHAKA”
     

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152. @ragdroid
     @droidconDE
     @BINDS
     

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153. @Module
     public class AppModule {
     @Provides
     BaseSchedulerProvider providerSchedulerProvider(SchedulerProvider provider) {
     return provider;
     }
     }
     @Binds
     

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154. @Module
     public class AppModule {
     @Provides
     BaseSchedulerProvider providerSchedulerProvider(SchedulerProvider provider) {
     return provider;
     }
     }
     @Binds
     @Module
     public abstract class AppModule {
     @Binds
     abstract BaseSchedulerProvider
     providerSchedulerProvider(SchedulerProvider provider);
     }
     

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155. @ragdroid
     @droidconDE
     MULTIBINDING
     

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156. MultiBinding @IntoSet
     @Provides String - “Hello”
     @Provides String - “Hi”
     @Provides String - “How are you?”
     

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157. @Provides String - “Hello”
     @Provides String - “Hi”
     @Provides String - “How are you?”
     @IntoSet
     @IntoSet
     @IntoSet
     MultiBinding @IntoSet
     

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158. @Provides Set
     {“Hello”, “Hi”, “How are you?”}
     MultiBinding @IntoSet
     

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159. MultiBinding @IntoMap
     <>
     Contract.Presenter
     MapPresenter JustPresenter TakePresenter
     

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160. MultiBinding @IntoMap
     @Provides MapPresenter mapPresenter
     @Provides JustPresenter justPresenter
     @Provides TakePresenter takePresenter
     

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161. MultiBinding @IntoMap
     @Provides MapPresenter mapPresenter
     @Provides JustPresenter justPresenter
     @Provides TakePresenter takePresenter
     @IntoMap
     @IntoMap
     @IntoMap
     

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162. MultiBinding @IntoMap
     @Provides MapPresenter mapPresenter
     @Provides JustPresenter justPresenter
     @Provides TakePresenter takePresenter
     @IntoMap
     @IntoMap
     @IntoMap
     @ClassKey(MapPresenter.java)
     @ClassKey(JustPresenter.java)
     @ClassKey(TakePresenter.java)
     

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163. MultiBinding @IntoMap
     @Provides
     Map
     {
     mapPresenter,
     justPresenter,
     takePresenter
     }
     

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164. DAGGER 2
     ANDROID
     “BEFRIEND THE BEAST”
     

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165. @ragdroid
     @droidconDE
     DAHAKA
     APPLICATION
     

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166. class DahakaApplication : Application(), HasActivityInjector {
     @Inject internal lateinit var
     activityInjector: DispatchingAndroidInjector
     …
     override fun activityInjector(): AndroidInjector {
     return activityInjector
     }
     …
     }
     DahakaApplication
     

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167. class DahakaApplication : Application(), HasActivityInjector {
     @Inject internal lateinit var
     activityInjector: DispatchingAndroidInjector
     …
     override fun activityInjector(): AndroidInjector {
     return activityInjector
     }
     …
     }
     DahakaApplication
     

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168. class DahakaApplication : Application(), HasActivityInjector {
     @Inject internal lateinit var
     activityInjector: DispatchingAndroidInjector
     …
     override fun activityInjector(): AndroidInjector {
     return activityInjector
     }
     …
     }
     DahakaApplication
     

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169. class DahakaApplication : Application(), HasActivityInjector {
     @Inject internal lateinit var
     activityInjector: DispatchingAndroidInjector
     …
     override fun activityInjector(): AndroidInjector {
     return activityInjector
     }
     …
     }
     DahakaApplication
     

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170. public interface HasActivityInjector {
     AndroidInjector activityInjector();
     }
     HasActivityInjector
     

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171. HasActivityInjector
     • A simple interface.
     • Implementing class “Has” ActivityInjector.
     • ActivityInjector = AndroidInjector.
     public interface HasActivityInjector {
     AndroidInjector activityInjector();
     }
     

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172. HasActivityInjector
     <>
     HasActivityInjector
     fun activityInjector() :
     AndroidInjector
     

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173. HasActivityInjector
     <>
     HasActivityInjector
     fun activityInjector() :
     AndroidInjector
     DahakaApplication
     • activityInjector :
     DispatchingAndroidInjector
     

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174. HasActivityInjector
     <>
     HasActivityInjector
     fun activityInjector() :
     AndroidInjector
     DahakaApplication
     • activityInjector :
     DispatchingAndroidInjector
     <>
     AndroidInjector
     fun inject(Activity instance)
     

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175. HasActivityInjector
     <>
     HasActivityInjector
     fun activityInjector() :
     AndroidInjector
     DahakaApplication
     • activityInjector :
     DispatchingAndroidInjector
     DispatchingAndroidInjector
     • inject(Activity activity)
     • injectorFactories : Map
     <>
     AndroidInjector
     fun inject(Activity instance)
     

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176. DispatchingAndroidInjector
     • Injects members for Android types : Activity, Fragment, etc
     • Has a Map> injectorFactories.
     

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177. DispatchingAndroidInjector
     Provider
     LoginActivity.class
     Class Provider>
     DispatchingAndroidInject
     • gets the Subcomponent.Builder from Map.
     • creates an instance using Builder.
     • calls component.inject(instance) to perform injections.
     • Injects members for Android types : Activity, Fragment, etc
     • Has a Map> injectorFactories.
     

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178. Provider
     HomeActivity.class
     ItemsActivity.class Provider
     Provider
     ProfileFragment.class
     MovesFragment.class Provider
     Class Provider>
     Provider
     StatsFragment.class
     DispatchingAndroidInjector
     Provider
     LoginActivity.class
     Class Provider>
     DispatchingAndroidInject
     DispatchingAndroidInject
     

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179. @ragdroid
     @droidconDE
     APP COMPONENT
     

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180. @Singleton
     @Component(modules = arrayOf(AppModule::class, ApiModule::class,
     AppBindingModule::class, AndroidSupportInjectionModule::class))
     interface AppComponent : AndroidInjector {
     …
     }
     AppComponent
     

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181. AppBindingModule
     @Singleton
     @Component(modules = arrayOf(AppModule::class, ApiModule::class,
     AppBindingModule::class, AndroidSupportInjectionModule::class))
     interface AppComponent : AndroidInjector {
     …
     }
     AppComponent
     

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182. @Module
     abstract class AppBindingModule {
     @ContributesAndroidInjector(modules = arrayOf(LoginModule::class))
     @ActivityScope
     internal abstract fun loginActivity(): LoginActivity
     }
     AppBindingModule
     

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183. @ContributesAndroidInjector
     @Module
     abstract class AppBindingModule {
     @ContributesAndroidInjector(modules = arrayOf(LoginModule::class))
     @ActivityScope
     internal abstract fun loginActivity(): LoginActivity
     }
     AppBindingModule
     

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184. @Module
     abstract class AppBindingModule {
     @ContributesAndroidInjector(modules = arrayOf(LoginModule::class))
     @ActivityScope
     internal abstract fun loginActivity(): LoginActivity
     }
     AppBindingModule
     • If your Module is stateless.
     • If your Subcomponent.Builder is simple and doesn’t need to bind anything extra.
     • @ContributesAndroidInjector will generate the SubComponent for you.
     • No need to create LoginActivitySubcomponent class in the above case.
     @ContributesAndroidInjector
     AppBindingModule
     

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185. @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
     

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186. @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 {
     @Subcomponent.Builder
     abstract class Builder extends AndroidInjector.Builder {}
     }
     }
     LoginBindingModule(Generated)
     

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187. @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 {
     @Subcomponent.Builder
     abstract class Builder extends AndroidInjector.Builder {}
     }
     }
     LoginBindingModule(Generated)
     

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188. @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 {
     @Subcomponent.Builder
     abstract class Builder extends AndroidInjector.Builder {}
     }
     }
     LoginBindingModule(Generated)
     

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189. @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 {
     @Subcomponent.Builder
     abstract class Builder extends AndroidInjector.Builder {}
     }
     }
     LoginBindingModule(Generated)
     

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190. @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 {
     @Subcomponent.Builder
     abstract class Builder extends AndroidInjector.Builder {}
     }
     }
     LoginBindingModule(Generated)
     

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191. AndroidSupportInjectionModule
     AppBindingModule
     @Singleton
     @Component(modules = arrayOf(AppModule::class, ApiModule::class,
     AppBindingModule::class, AndroidSupportInjectionModule::class))
     interface AppComponent : AndroidInjector {
     …
     }
     AppComponent
     

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192. @Beta
     @Module(includes = AndroidInjectionModule.class)
     public abstract class AndroidSupportInjectionModule {
     @Multibinds
     abstract Map, AndroidInjector.Factory extends Fragment>>
     supportFragmentInjectorFactories();
     private AndroidSupportInjectionModule() {}
     }
     @Beta
     @Module
     public abstract class AndroidInjectionModule {
     @Multibinds
     abstract Map, AndroidInjector.Factory extends Activity>>
     activityInjectorFactories();
     @Multibinds
     abstract Map, AndroidInjector.Factory extends Fragment>>
     fragmentInjectorFactories();
     …
     }
     AndroidSupportInjectionModule (dagger.android)
     

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193. @Beta
     @Module(includes = AndroidInjectionModule.class)
     public abstract class AndroidSupportInjectionModule {
     @Multibinds
     abstract Map, AndroidInjector.Factory extends Fragment>>
     supportFragmentInjectorFactories();
     private AndroidSupportInjectionModule() {}
     }
     @Beta
     @Module
     public abstract class AndroidInjectionModule {
     @Multibinds
     abstract Map, AndroidInjector.Factory extends Activity>>
     activityInjectorFactories();
     @Multibinds
     abstract Map, AndroidInjector.Factory extends Fragment>>
     fragmentInjectorFactories();
     …
     }
     AndroidSupportInjectionModule (dagger.android)
     

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194. @Beta
     @Module(includes = AndroidInjectionModule.class)
     public abstract class AndroidSupportInjectionModule {
     @Multibinds
     abstract Map, AndroidInjector.Factory extends Fragment>>
     supportFragmentInjectorFactories();
     private AndroidSupportInjectionModule() {}
     }
     @Beta
     @Module
     public abstract class AndroidInjectionModule {
     @Multibinds
     abstract Map, AndroidInjector.Factory extends Activity>>
     activityInjectorFactories();
     @Multibinds
     abstract Map, AndroidInjector.Factory extends Fragment>>
     fragmentInjectorFactories();
     …
     }
     AndroidSupportInjectionModule (dagger.android)
     

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195. @Beta
     @Module(includes = AndroidInjectionModule.class)
     public abstract class AndroidSupportInjectionModule {
     @Multibinds
     abstract Map, AndroidInjector.Factory extends Fragment>>
     supportFragmentInjectorFactories();
     private AndroidSupportInjectionModule() {}
     }
     @Beta
     @Module
     public abstract class AndroidInjectionModule {
     @Multibinds
     abstract Map, AndroidInjector.Factory extends Activity>>
     activityInjectorFactories();
     @Multibinds
     abstract Map, AndroidInjector.Factory extends Fragment>>
     fragmentInjectorFactories();
     …
     }
     AndroidSupportInjectionModule (dagger.android)
     

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196. @Beta
     @Module(includes = AndroidInjectionModule.class)
     public abstract class AndroidSupportInjectionModule {
     @Multibinds
     abstract Map, AndroidInjector.Factory extends Fragment>>
     supportFragmentInjectorFactories();
     private AndroidSupportInjectionModule() {}
     }
     @Beta
     @Module
     public abstract class AndroidInjectionModule {
     @Multibinds
     abstract Map, AndroidInjector.Factory extends Activity>>
     activityInjectorFactories();
     @Multibinds
     abstract Map, AndroidInjector.Factory extends Fragment>>
     fragmentInjectorFactories();
     …
     }
     AndroidSupportInjectionModule (dagger.android)
     

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197. @ragdroid
     @droidconDE
     LOGIN ACTIVITY
     

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198. public class LoginActivity {
     @Inject
     LoginContract.Presenter presenter;
     @Override
     protected void onCreate(Bundle savedInstanceState) {
     AndroidInjection.inject(this);
     }
     }
     LoginActivity
     

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199. AndroidInjection.inject(LoginActivity)
     LoginActivity
     public class LoginActivity {
     @Inject
     LoginContract.Presenter presenter;
     @Override
     protected void onCreate(Bundle savedInstanceState) {
     AndroidInjection.inject(this);
     }
     }
     

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200. AndroidInjection.inject(LoginActivity)
     AndroidInjection.inje
     

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201. AndroidInjection.inject(LoginActivity)
     AndroidInjection.inje
     AndroidInjection
     

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202. AndroidInjection.inject(LoginActivity)
     AndroidInjection.inje
     AndroidInjection DaggerAppComponent
     

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203. AndroidInjection.inject(LoginActivity)
     AndroidInjection.inje
     AndroidInjection DaggerAppComponent AppBindingModule_LoginActivity
     DispatchingAndroidInjector
     

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204. AndroidInjection.inject(LoginActivity)
     AndroidInjection.inje
     AndroidInjection DaggerAppComponent AppBindingModule_LoginActivity
     DispatchingAndroidInjector
     

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205. AndroidInjection.inject(LoginActivity)
     AndroidInjection.inje
     AndroidInjection DaggerAppComponent AppBindingModule_LoginActivity
     DispatchingAndroidInjector
     ApiModule_ProvideRetrofitFactory
     AppModule_ProviderSchedulerProviderFactory
     ApiModule_ProvidePokemonServiceFactory
     ApiModule_ProvideRetrofitFactory
     AppModule_ProviderSchedulerProviderFactory
     ApiModule_ProvidePokemonServiceFactory
     

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206. @ragdroid
     @droidconDE
     BEFRIEND THE BEAST
     “You can not change your fate,
     No droid can.”
     

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207. AndroidInjection.inject(LoginActivity)
     

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208. AndroidInjection.inject(LoginActivity)
     activity
     .getApplication()
     LoginActivity
     

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209. AndroidInjection.inject(LoginActivity)
     activity
     .getApplication()
     LoginActivity
     application
     .activityInjector()
     DahakaApplication : HasActivityInjector
     

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210. AndroidInjection.inject(LoginActivity)
     activity
     .getApplication()
     LoginActivity
     application
     .activityInjector()
     DahakaApplication : HasActivityInjector
     activityInjector
     .inject(activity)
     DispatchingAndroidInjector : AndroidInjector
     

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211. AndroidInjection.inject(LoginActivity)
     activity
     .getApplication()
     LoginActivity
     application
     .activityInjector()
     DahakaApplication : HasActivityInjector
     activityInjector
     .inject(activity)
     DispatchingAndroidInjector : AndroidInjector
     

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212. DispatchingAndroidInjector.inject(LoginActivity)
     injectorFactories
     .get(LoginActivity.class)
     DispatchingAndroidInjector : AndroidInjector
     

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213. DispatchingAndroidInjector : AndroidInjector
     Factory : LoginSubcomponent.Builder
     injectorFactories
     .get(LoginActivity.class)
     DispatchingAndroidInjector.inject(LoginActivity)
     builder
     .build()
     

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214. DispatchingAndroidInjector : AndroidInjector
     Factory : LoginSubcomponent.Builder
     component
     .inject(activity)
     LoginSubcomponent
     injectorFactories
     .get(LoginActivity.class)
     DispatchingAndroidInjector.inject(LoginActivity)
     builder
     .build()
     

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215. DispatchingAndroidInjector : AndroidInjector
     builder
     .build()
     Factory : LoginSubcomponent.Builder
     component
     .inject(activity)
     LoginSubcomponent
     DispatchingAndroidInjector.inject(LoginActivity)
     injectorFactories
     .get(LoginActivity.class)
     

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216. • DaggerApplication
     • DaggerActivity
     • DaggerBroadcastReceiver
     • DaggerContentProvider
     • DaggerFragment
     • DaggerIntentService
     • DaggerService
     Dagger Boilerplate classes
     

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217. @ragdroid
     @droidconDE
     TESTING
     WITH
     DAGGER 2 ANDROID
     

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218. public class LoginActivity {
     @Inject
     LoginContract.Presenter presenter;
     @Override
     protected void onCreate(Bundle savedInstanceState) {
     AndroidInjection.inject(this);
     }
     }
     LoginActivity
     

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219. public class LoginActivity {
     @Inject
     LoginContract.Presenter presenter;
     @Override
     protected void onCreate(Bundle savedInstanceState) {
     AndroidInjection.inject(this);
     }
     }
     LoginActivity
     

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220. @Module
     public class TestLoginModule {
     @Mock LoginPresenter loginPresenter;
     public TestLoginModule() {
     MockitoAnnotations.initMocks(this);
     }
     @Provides
     @ActivityScope
     public LoginContract.Presenter provideLoginPresenter() {
     return loginPresenter;
     }
     }
     TestLoginModule
     

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221. @Module
     public class TestLoginModule {
     @Mock LoginPresenter loginPresenter;
     public TestLoginModule() {
     MockitoAnnotations.initMocks(this);
     }
     @Provides
     @ActivityScope
     public LoginContract.Presenter provideLoginPresenter() {
     return loginPresenter;
     }
     }
     TestLoginModule
     

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222. @Module
     public class TestLoginModule {
     @Mock LoginPresenter loginPresenter;
     public TestLoginModule() {
     MockitoAnnotations.initMocks(this);
     }
     @Provides
     @ActivityScope
     public LoginContract.Presenter provideLoginPresenter() {
     return loginPresenter;
     }
     }
     TestLoginModule
     

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223. Demo Code
     • Dahaka Demo :
     https://github.com/ragdroid/Dahaka
     • Branches :
     • dagger-android : Pokemon app using dagger-android (With Tests, Fragments)
     • dagger-android-dependent-comp : dagger-android with Dependent Component
     • dagger-android-dependent-comp-kotlin : In Kotlin
     • subcomponent : UserComponent as subcomponent
     • dependent-component : UserComponent as dependent component
     • dependent-component-kotlin : In Kotlin
     

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224. @ragdroid
     @droidconDE
     Dagger 2 Android = Dahaka
     • D
     • A
     • H
     • A
     • K
     • A
     Dagger
     Android
     HasActivityInjector
     AndroidInjection
     Keys
     AndroidInjector
     

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225. @ragdroid
     @droidconDE
     Dagger 2 Android
     “You can not change your fate,
     No droid can”
     Let’s befriend the beast instead.
     

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226. 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)
     

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227. 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
     • Android Dialogs : Mike Nakhimovich
     https://www.youtube.com/watch?v=KwRXQ6nT7jQ
     • 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
     

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228. 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
     

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229. @ragdroid
     @droidconDE
     CUT
     SCENES
     

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230. Dagger 2 Android
     “Defeat the Dahaka"
     Garima Jain
     @ragdroid
     

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231. Dagger 2 Android
     “Defeat the Dahaka"
     Garima Jain
     @ragdroid
     

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232. FUELED
     http://fueled.com/garima
     garima@fueled.com
     VIELEN DANK
     THANK YOU
     

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233. FUELED
     http://fueled.com/garima
     garima@fueled.com
     Q & A
     DISCUSSION
     @ragdroid
     

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