Android App Architecture - MCE2016

Transcript

1. Effective Android Architecture
2. Hello! I am Richa Software Engineer at Coursera
4. ▪Challenges ▪Finding the right architecture fit ▪Validation ▪Demo and Samples ▪Cons ▪Key Takeaways Structure of the talk
5. A can transform their life by accessing the world’s best learning experience. “
6. Available on Google Play Store Place your screenshot here Android App 1,825+ COURSES 18M+ LEARNERS 141+ PARTNERS
7. Single learning platform, multiple delivery mediums
8. 109% increase in mobile usage since last year 24 % use mobile only 40 % use mobile and desktop
9. Over 500k (and growing) new learners join Coursera every month
10. Cross team Tightly aligned, loosely coupled Faster MVPs Learn fast, fail fast Network Speeds Edge, 2G, Spotty
11. Who all has ever used MVC?
12. MVC
13. MVP ? MVC ? MVVM ?
14. MODEL VIEW CONTROLLER Manage application data Render model Handle view events Interact with model Invoke next UI Table of Responsibilities
15. Mobile Web Desktop
17. MODEL VIEW CONTROLLER Manage data from network Render model Handle view events Manage data from local storage Manage view state Interact with model Manage model consistency Navigation Interact with system components Interact with system events Update view on model changes or system events
18. Model public class CourseModel { Course getFromDatabase() { // fetch from db, or local cache } Course getFromNetwork() { // fetch from apis, cache when possible } }
19. View public class ExpandableCourseListActivity { void onSaveInstanceState(Bundle b) { // save all expanded states } }
20. Controller void onClick() {} void onModelUpdated() {} void onNewNotification() {} void onLocationUpdated(Location loc) {} void takePhoto(Activity context) {} void launchView(Activity context ) {}
22. MVC ??
23. MODEL VIEW CONTROLLER Manage data from local storage Render model Handle view events Manage data from network Manage view state Interact with model Manage model consistency Navigation Interact with system components Interact with system events Update view on model changes or system events
24. Interactor?
26. MODEL VIEW CONTROLLER INTERACTOR Manage data from local storage Render view data Handle view events Interact with external entities Manage data from network Manage view data/ updates Navigation Manage model consistency Forward view data updates to view
27. View Model ?
29. MODEL VIEW CONTROLLER INTERACTOR VIEW MODEL Manage data from local storage Render view model Handle view events Interact with external entities Manage view data Manage data from network Navigation Manage model consistency Manage view model
30. Presenter ?
31. MODEL VIEW PRESENTER INTERACTOR VIEW MODEL Manage data from local storage Render view model Handle view events Interact with external entities Manage view data Manage data from network Navigation Manage model consistency Manage view model
32. Data Source
33. ENTITIES VIEW PRESENTER INTERACTOR VIEW MODEL Represent model objects Render view model Handle view events Interact with external entities Manage view data Navigation Manage view model
34. FlowController ?
36. ENTITIES VIEW PRESENTER INTERACTOR VIEW MODEL FLOW CONTROLLER Represent model objects Render view model Manage view events and view model Interact with external entities Manage view data Navigation
38. Apply Dependency Inversion
42. Espresso + Mocking JUnit + Mocking Android/ JUnit + Mocking Android/ JUnit + Mocks
44. Code Demo - Sample app
45. Source Code https://github.com/richk/ CourseraDemoApp
46. Classes • MainActivity • FlowController • CatalogActivity • CatalogPresenter • CatalogViewModel • CatalogInteractor
47. MainActivity void onCreate() { FlowController.getInstance() .launchCatalogActivity(this); }
48. FlowController void launchCatalogActivity(Context c) { Intent intent = …; c.startActivity(intent) }
49. CatalogActivity CatalogPresenter presenter; void onCreate() { presenter = new CatalogPresenter(this); }
50. CatalogActivity void onResume() { Action1<Catalog> action = ; presenter.subscribeToUpdates(action) }
51. CatalogActivity void onPause() { presenter.unsubscribeToUpdates(); }
52. CatalogPresenter CatalogInteractor interactor; CatalogPresenter(Context c) { viewModel = new CatalogViewModel(); interactor = new CatalogInteractor(c); loadCatalog(); }
53. CatalogPresenter void loadCatalog() { interactor.loadCourses().observeOn(AndroidSchedulers.mainThread()) .subscribe(new Action1<>() { @Override public void call(List<Course> courses) { // update the view model } }); }
54. CatalogViewModel // Parcelable public final Catalog catalog = new Catalog();
55. CatalogInteractor Context mContext; public CatalogInteractor(Context context) { mContext = context; } public Observable loadCatalog() { return catalogDataSource.loadCatalog(mContext.getApplication( )); }
57. The Cons
58. Dealing with context Presenter(Context context) Interactor(Context context) NetworkClient(Context context) PersistenceClient(Context context) context.getSystemService(“SERVICE”) context.startActivity(intent) context.startActivityForResult(intent)
59. Tedium ~ 4 classes per feature/module
60. Adopting as a team Educating new hires
61. Key Takeaways
62. Ship the latest ideas
63. Refactor or Not?
64. Validate
65. Iterate, Iterate, Iterate
67. We Are Hiring! Apply
68. @richa123 rkhandelwal@coursera.org richk in/richak Thank You
69. Questions ?