Introdução ao Dagger 2

Uma introdução abordada com códigos de exemplo para demonstrar a necessidade e como utilizar da forma mais simples possível o framework de injeção de dependência "Dagger".

Transcript

1. Introdução ao Dagger 2 Marcello Galhardo
2. @marcellogalhardo @marcellogalhardo @MarcelloGalhard marcello.galhardo@gmail.com /marcellogalhardo Android Dev BR slack.androiddevbr.org
3. Você conhece... ...inversão de controle?
4. Você conhece... ...inversão de controle? ...Dagger?
5. Por que usar Injeção de Dependência?
6. Reusar componentes
7. Segurança ao refatorar
8. Facilidade nos testes
9. Activity
10. Presenter Activity
11. Presenter Repository Activity
12. Presenter Repository Activity Api
13. Presenter Repository Activity Cache Api
14. public class Activity extends AppCompatActivity { private Presenter presenter; @Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); presenter = new Presenter(); } } public class Presenter { private Repository repository; public Presenter() { repository = new Repository(); } } Activity.java / Presenter.java
15. public class Activity extends AppCompatActivity { private Presenter presenter; @Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); presenter = new Presenter(); } } public class Presenter { private Repository repository; public Presenter() { repository = new Repository(); } } Activity.java / Presenter.java
16. public class Activity extends AppCompatActivity { private Presenter presenter; @Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); Api api = new Api(); Cache cache = new Cache(); Repository repository = new Repository(api, cache); presenter = new Presenter(repository); } } Activity.java
17. public class Activity extends AppCompatActivity { private Presenter presenter; @Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); Api api = new Api(); Cache cache = new Cache(); Repository repository = new Repository(api, cache); presenter = new Presenter(repository); } } Activity.java
18. • Muito código boilerplate; Problemas!
19. • Muito código boilerplate; • Dificuldade em manter a árvore de dependências. Problemas!
20. Vamos falar de Dagger
21. Dagger 2 • Não usa Reflection, código gerado em buildtime;
22. Dagger 2 • Não usa Reflection, código gerado em buildtime; • Fácil de depurar;
23. Dagger 2 • Não usa Reflection, código gerado em buildtime; • Fácil de depurar; • Facilidade de manter árvores de dependência.
24. app/build.gradle dependencies { annotationProcessor "com.google.dagger:dagger-compiler:2.8" compile "com.google.dagger:dagger:2.8" provided "org.glassfish:javax.annotation:2.8" }
25. @Singleton @Component(modules = { MainModule.class, ...}) public interface MainComponent { void inject(Activity activity); } MainComponent.java
26. @Singleton @Component(modules = { MainModule.class, ...}) public interface MainComponent { void inject(Activity activity); } MainComponent.java
27. @Singleton @Component(modules = { MainModule.class, ...}) public interface MainComponent { void inject(Activity activity); } MainComponent.java
28. @Singleton @Component(modules = { MainModule.class, ...}) public interface MainComponent { void inject(Activity activity); } MainComponent.java
29. @Singleton @Component(modules = { MainModule.class, ...}) public interface MainComponent { void inject(Activity activity); } MainComponent.java
30. @Singleton @Component(modules = { MainModule.class, ...}) public interface MainComponent { void inject(Activity activity); } MainComponent.java
31. MainModule.java @Module public class MainModule { private static final int CACHE_SIZE_10_MB = 10 * 1024 * 1024; private static final int TIMEOUT = 20; @Provides public Presenter providesPresenter(Repository repository) { return new Presenter(repository); } @Provides @Reusable public Repository repository(Cache cache, Api api) { return new Repository(cache, api); } @Provides @Singleton public Cache providesCache() { return new Cache(CACHE_SIZE_10_MB); } @Provides @Reusable public Api providesApi() { return new Api(TIMEOUT); } }
32. MainModule.java @Module public class MainModule { private static final int CACHE_SIZE_10_MB = 10 * 1024 * 1024; private static final int TIMEOUT = 20; @Provides public Presenter providesPresenter(Repository repository) { return new Presenter(repository); } @Provides @Reusable public Repository repository(Cache cache, Api api) { return new Repository(cache, api); } @Provides @Singleton public Cache providesCache() { return new Cache(CACHE_SIZE_10_MB); } @Provides @Reusable public Api providesApi() { return new Api(TIMEOUT); } }
33. MainModule.java @Module public class MainModule { private static final int CACHE_SIZE_10_MB = 10 * 1024 * 1024; private static final int TIMEOUT = 20; @Provides public Presenter providesPresenter(Repository repository) { return new Presenter(repository); } @Provides @Reusable public Repository repository(Cache cache, Api api) { return new Repository(cache, api); } @Provides @Singleton public Cache providesCache() { return new Cache(CACHE_SIZE_10_MB); } @Provides @Reusable public Api providesApi() { return new Api(TIMEOUT); } }
34. MainModule.java @Module public class MainModule { private static final int CACHE_SIZE_10_MB = 10 * 1024 * 1024; private static final int TIMEOUT = 20; @Provides public Presenter providesPresenter(Repository repository) { return new Presenter(repository); } @Provides @Reusable public Repository repository(Cache cache, Api api) { return new Repository(cache, api); } @Provides @Singleton public Cache providesCache() { return new Cache(CACHE_SIZE_10_MB); } @Provides @Reusable public Api providesApi() { return new Api(TIMEOUT); } }
35. MainModule.java @Module public class MainModule { private static final int CACHE_SIZE_10_MB = 10 * 1024 * 1024; private static final int TIMEOUT = 20; @Provides public Presenter providesPresenter(Repository repository) { return new Presenter(repository); } @Provides @Reusable public Repository repository(Cache cache, Api api) { return new Repository(cache, api); } @Provides @Singleton public Cache providesCache() { return new Cache(CACHE_SIZE_10_MB); } @Provides @Reusable public Api providesApi() { return new Api(TIMEOUT); } }
36. MainModule.java @Module public class MainModule { private static final int CACHE_SIZE_10_MB = 10 * 1024 * 1024; private static final int TIMEOUT = 20; @Provides public Presenter providesPresenter(Repository repository) { return new Presenter(repository); } @Provides @Reusable public Repository repository(Cache cache, Api api) { return new Repository(cache, api); } @Provides @Singleton public Cache providesCache() { return new Cache(CACHE_SIZE_10_MB); } @Provides @Reusable public Api providesApi() { return new Api(TIMEOUT); } }
37. MainModule.java @Module public class MainModule { private static final int CACHE_SIZE_10_MB = 10 * 1024 * 1024; private static final int TIMEOUT = 20; @Provides public Presenter providesPresenter(Repository repository) { return new Presenter(repository); } @Provides @Reusable public Repository repository(Cache cache, Api api) { return new Repository(cache, api); } @Provides @Singleton public Cache providesCache() { return new Cache(CACHE_SIZE_10_MB); } @Provides @Reusable public Api providesApi() { return new Api(TIMEOUT); } }
38. MainModule.java @Module public class MainModule { private static final int CACHE_SIZE_10_MB = 10 * 1024 * 1024; private static final int TIMEOUT = 20; @Provides public Presenter providesPresenter(Repository repository) { return new Presenter(repository); } @Provides @Reusable public Repository repository(Cache cache, Api api) { return new Repository(cache, api); } @Provides @Singleton public Cache providesCache() { return new Cache(CACHE_SIZE_10_MB); } @Provides @Reusable public Api providesApi() { return new Api(TIMEOUT); } }
39. MainModule.java @Module public class MainModule { private static final int CACHE_SIZE_10_MB = 10 * 1024 * 1024; private static final int TIMEOUT = 20; @Provides public Presenter providesPresenter(Repository repository) { return new Presenter(repository); } @Provides @Reusable public Repository repository(Cache cache, Api api) { return new Repository(cache, api); } @Provides @Singleton public Cache providesCache() { return new Cache(CACHE_SIZE_10_MB); } @Provides @Reusable public Api providesApi() { return new Api(TIMEOUT); } }
40. MainApplication.java public class MainApplication extends Application { private MainComponent component; @Override public void onCreate() { super.onCreate(); component = DaggerMainComponent.builder().build(); } public MainComponent getComponent() { return component; } }
41. MainApplication.java public class MainApplication extends Application { private MainComponent component; @Override public void onCreate() { super.onCreate(); component = DaggerMainComponent.builder().build(); } public MainComponent getComponent() { return component; } }
42. MainApplication.java public class MainApplication extends Application { private MainComponent component; @Override public void onCreate() { super.onCreate(); component = DaggerMainComponent.builder().build(); } public MainComponent getComponent() { return component; } }
43. MainApplication.java public class MainApplication extends Application { private MainComponent component; @Override public void onCreate() { super.onCreate(); component = DaggerMainComponent.builder().build(); } public MainComponent getComponent() { return component; } }
44. Activity
45. Application Activity
46. Application Component Activity
47. Application Component Activity MainModule
48. Application Component Activity Modules... MainModule
49. Activity.java public class Activity extends AppCompatActivity { @Inject Presenter presenter; @Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); MainApplication application = getMainApplication(); MainComponent component = application.getComponent(); component.inject(this); } }
50. Activity.java public class Activity extends AppCompatActivity { @Inject Presenter presenter; @Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); MainApplication application = getMainApplication(); MainComponent component = application.getComponent(); component.inject(this); } }
51. Activity.java public class Activity extends AppCompatActivity { @Inject Presenter presenter; @Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); MainApplication application = getMainApplication(); MainComponent component = application.getComponent(); component.inject(this); } }
52. Activity.java public class Activity extends AppCompatActivity { @Inject Presenter presenter; @Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); MainApplication application = getMainApplication(); MainComponent component = application.getComponent(); component.inject(this); } }
53. Repository Cache Api
54. Repository MockCache MockApi Api Cache
55. Exemplos
56. github.com/marcellogalhardo/events
57. github.com/marcellogalhardo/locations
58. www.concretesolutions.com.br Rio de Janeiro – Rua São José, 90 – cj. 2121 Centro – (21) 2240-2030 São Paulo - Av. Nações Unidas, 11.541 3º andar - Brooklin - (11) 4119-0449 Ajudamos empresas a criar produtos digitais de sucesso