Clean Android Architecture

Diving into problems with MVC and refactoring it into Clean Architecture - VIPER + MVVM, and talking about pros and cons of this architecture.

Transcript

1. CLEAN ARCHITECTURE
2. Richa Khandelwal rkhandelwal@coursera.org @richa123
8. Who all has ever used MVC?
11. MODEL VIEW CONTROLLER Interact with DB Render Model Handle view events Update model Invoke next UI
12. Mobile Web Desktop Mobile is diffrent, don’t generalize based on this
14. MODEL VIEW CONTROLLER Interact with DB Render Model Handle view events Interact with API/cloud code Manage view state Update model Invoke another view Interact with system components Handle system events Update view based on system events
15. Model public class CourseModel { public Course getFromDatabase() { …. } public void getFromNetwork() { …. } }
16. View public class ExpandableCourseListActivity { public void onPause() { // save all expanded states } public void onResume() { // restore all expanded states } }
17. Controller public void onClick() {} public void onModelUpdated() {} public void onNewNotification() {} public void onLocationUpdated(Location location) {} public void takePhoto(Activity activityContext) {} public void launchProfilePage(Activity activityContext ) {}
22. MODEL VIEW CONTROLLER Interact with DB Render Model Handle view events Interact with API/cloud code Manage view state Update model Invoke another view Interact with system components Handle system events Update view based on system events
23. Interactor?
24. JUnit + Mocking
25. MODEL VIEW CONTROLLER INTERACTOR Retrieve data from Network Render Model Handle view events Interact with external entities Retrieve data from API/cloud code Manage view state Invoke another view Forward system events to view Forward model updates to view
26. View Model ?
27. JUnit + Mocking Android + Mocking Espresso + Mocking
28. MODEL VIEW CONTROLLER INTERACTOR VIEW MODEL Retrieve data from Network Render View Model Handle view events Interact with external entities Encapsulate view state and behavior Retrieve data from API/ cloud code Invoke another view Update view state
29. Presenter ?
30. MODEL VIEW PRESENTER INTERACTOR VIEW MODEL Retrieve data from Network Render View Model Handle view events Interact with external entities Encapsulate view state and behavior Retrieve data from API/ cloud code Invoke another view Update view state
31. Espresso + Mocking JUnit + Mocking JUnit + Mocking Android + Mocking
32. ENTITIES VIEW PRESENTER INTERACTOR VIEW MODEL Retrieve data from Data Sources Render View Model Handle view events Interact with external entities Encapsulate view state and behavior Invoke another view Update view state
33. Router ?
34. Android + Mocks
35. ENTITIES VIEW PRESENTER INTERACTOR VIEW MODEL ROUTER Retrieve data from Data Sources Render View Model Handle view events Interact with external entities Encapsulate view state and behavior Invoke another view Update view state
37. Apply Dependency Inversion
41. Clean Android Architecture Architecture is about Intents not Frameworks - Uncle Bob
43. App to list courses on coursera using Catalog API Github Link -
44. Classes • MainActivity • CatalogRouter • CatalogActivity • CatalogPresenter • CatalogViewModel • CatalogInteractor
45. MainActivity public void onCreate() { CatalogRouter.getInstance().launchCatalogActivity(); }
46. CatalogRouter public void launchCatalogActivity(Context context) { Intent intent = …; context.startActivity(intent) }
47. CatalogActivity CatalogPresenter presenter; Action1<Throwable> onError = new Action1<Throwable>() { public void call(Throwable throwable) { // handle error } });
48. CatalogActivity public void onCreate() { presenter = new CatalogPresenter(this); presenter.loadCatalog(onError); }
49. CatalogActivity public void onResume() { Action1<Catalog> catalogUpdateAction = ; presenter.subscribeToCatalogUpdates(catalogUpdat eAction) }
50. CatalogActivity public void onPause() { presenter.unsubscribeToCatalogUpdates(); }
51. CatalogPresenter CatalogInteractor interactor; public CatalogPresenter(Context context) { viewModel = new CatalogViewModel(); interactor = new CatalogInteractor(context) }
52. CatalogPresenter public void loadCatalog() { interactor.loadInteractor() .subscribe(new Action1<List<Course>>() { @Override public void call(List<Course> courses) { getData().mCourseList.onNext(courses); } }); }
53. CatalogPresenter public void subscribeToCatalogUpdates(Action1 action) { viewModel.subscribeToUpdates(action); } public void unsubscribeToCatalogUpdates() { viewModel.subscribeToUpdates(); }
54. CatalogViewModel public final BehaviorSubject<Catalog> catalog = BehaviorSubject.create(); public void subscribeToCatalog(Action1 action) { catalog.subscribe(action); } public void unsubscribeToCatalog() { catalog.unsubscribe(action); }
55. CatalogInteractor Context mContext; public CatalogInteractor(Context context) { mContext = context; } public Observable loadCatalog() { return catalogDataSource.loadCatalog(); }
60. Dealing with Context
61. After thoughts
62. Build features in new architecture rather than refactor Validate Iterate - learn and apply Don’t refactor all the time
64. Coursera is hiring!
65. Questions ? Thank You!