Scalable applications: Make it Clean, make it Simple

I spent the last 7 years thinking of what should be the best Android architecture in terms of simplicity and maintenance, in terms of excellence in the Android programming context. I teach this vision during all those previous years, providing trainings, conferences, books, tutorials, articles, Github projects.
And this year I faced an awesome challenge in terms of architecture for an important project that will impact billions of users in the future. I had a team of 12 full time developers to make it. We spent a year on it. And we make it scalable in term of features, developers’ team and end users.
The project is now used to create the next generation of Android applications for connected car for the biggest car company. It has two faces; an application and a SDK.
This is the perfect time for a feed back, what worked, what didn’t, why you should avoid Rx and focus on testable architecture. Are there different architectures between a SDK and an application? What are the concerns when creating a SDK? If your application can not be a SDK, did you miss something?
Let’s say, we’ll have a discussion, a deep one, about Android architecture.

Transcript

1. @android2ee by(Mathias Seguy == Android2EE){ French Android Expert}
3. An Application ?
4. An Application ? Makeup View layer
5. An Application ? Makeup View layer
6. An Application ? Makeup View layer Muscles Model/Presenter layer
7. An Application ? Makeup View layer Muscles Model/Presenter layer
8. An Application ? Makeup View layer Muscles Model/Presenter layer Cortex Business Services layer
9. An Application ? Makeup View layer Muscles Model/Presenter layer Cortex Business Services layer
10. An Application ? Makeup View layer Muscles Model/Presenter layer Cortex Business Services layer Memory Local Storage layer
11. An Application ? Makeup View layer Muscles Model/Presenter layer Cortex Business Services layer Memory Local Storage layer
12. An Application ? Makeup View layer Muscles Model/Presenter layer Cortex Business Services layer Babylon Knowledge Communication layer Memory Local Storage layer
13. An Application ? Makeup View layer Muscles Model/Presenter layer Cortex Business Services layer Babylon Knowledge Communication layer Memory Local Storage layer
14. An Application ? Makeup View layer Muscles Model/Presenter layer Cortex Business Services layer Memory Local Storage layer Babylon Knowledge Communication layer Conscious memory DataStore layer
15. An Application ? Makeup View layer Muscles Model/Presenter layer Cortex Business Services layer Memory Local Storage layer Babylon Knowledge Communication layer Conscious memory DataStore layer
16. An Application ? Makeup View layer Muscles Model/Presenter layer Cortex Business Services layer Memory Local Storage layer Babylon Knowledge Communication layer Conscious memory DataStore layer Makeup
17. An Application ?
18. An Application ? Common knowledge Cross layer
19. An Application ?
20. An Application ?
21. An Application ? The Lord The Application Object
22. An Application ?
23. An Application ? Makeup View layer Muscles Model/Presenter layer Cortex Business Services layer Memory Local Storage layer Babylon Knowledge Communication layer Conscious memory DataStore layer Makeup View layer View layer is Responsible of • Displaying stuff • Following lifecycles • Grabing user’s actions
24. An Application ? Makeup View layer Muscles Model/Presenter layer Cortex Business Services layer Memory Local Storage layer Babylon Knowledge Communication layer Conscious memory DataStore layer Model/Presenter layer is Responsible of managing data displayed by the view: • Update data according to view’s calls • Update views according to data changes Muscles Model/Presenter layer
25. An Application ? Makeup View layer Muscles Model/Presenter layer Cortex Business Services layer Memory Local Storage layer Babylon Knowledge Communication layer Conscious memory DataStore layer Business Services layer is Responsible of implementing algorithms of your application. (All algorithms) Cortex Business Services layer
26. An Application ? Makeup View layer Muscles Model/Presenter layer Cortex Business Services layer Memory Local Storage layer Babylon Knowledge Communication layer Conscious memory DataStore layer DataStore layer is Responsible of implementing C.R.U.D. in your application in an abstract way. Conscious memory DataStore layer
27. An Application ? Makeup View layer Muscles Model/Presenter layer Cortex Business Services layer Memory Local Storage layer Babylon Knowledge Communication layer Conscious memory DataStore layer D.A.O. layer is Responsible of implementing C.R.U.D. in your application in the device. (Local storage) Memory Local Storage layer
28. An Application ? Makeup View layer Muscles Model/Presenter layer Cortex Business Services layer Memory Local Storage layer Babylon Knowledge Communication layer Conscious memory DataStore layer Communication layer is Responsible of communicating with the rest of the world … Well this means making CRUD with external system. Babylon Knowledge Communication layer
29. An Application ? Makeup View layer Muscles Model/Presenter layer Cortex Business Services layer Memory Local Storage layer Babylon Knowledge Communication layer Conscious memory DataStore layer Dependency (views depend on presenters,…)
30. An Application Makeup View layer Muscles Model/Presenter layer Cortex Business Services layer Memory Local Storage layer Babylon Knowledge Communication layer Conscious memory DataStore layer Is simple
31. A Jetpack Application Makeup View layer Muscles ViewModel Cortex Business Services layer Memory Local Storage layer Babylon Knowledge Communication layer Conscious memory DataStore layer Is simple LiveData Retrofit OkHttp/Okio/Moshi android.support.design android.support LiveData android.arch.lifecycle android.arch.persistence
33. Scalable ? Nonsense, There is only one user at a time Scalable Android application ?
34. Scalable ? The game is servers side. Users scalability ?
35. Scalable ? How to be able to add thousands of features ? Android side Features scalability ?
36. Scalable ? How to be able to grow from 3 to 20 developers and more ? Android side. Scalable team?
37. Scalable means And scalable team organization. Features scalability
38. Scalable ? UseCase Make strong fundations for your usecase
39. Scalable ? View layer Models layer Services layer Data layer fundation Use case 1 Use case 2 Use case 3 Use case 4 Use case 5 View layer Models layer Services layer Data layer
40. Scalable ? Concretly Implement it with flavors or module dependencies 1feature 1feature 1feature 1feature 1feature 1feature 1feature 1feature 1feature 1feature 1feature 1feature 1feature 1feature 1feature 1feature
41. More resources Mathias Seguy(Medium) Flavors, BuildTypes and Variants
43. Background Threads , Main Thread Async Makeup View layer Muscles Model/Presenter layer Cortex Business Services layer Memory Local Storage layer Babylon Knowledge Communication layer Conscious memory DataStore layer
44. Background Threads , Main Thread Async Makeup View layer Muscles Model/Presenter layer Cortex Business Services layer Memory Local Storage layer Babylon Knowledge Communication layer Conscious memory DataStore layer Use AsyncTask every where ?
45. Background Threads , Main Thread Async Makeup View layer Muscles Model/Presenter layer Cortex Business Services layer Memory Local Storage layer Babylon Knowledge Communication layer Conscious memory DataStore layer Use AsyncTask every where ?
46. Background Threads Main Thread Async Makeup View layer Muscles Model/Presenter layer Cortex Business Services layer Memory Local Storage layer Babylon Knowledge Communication layer Conscious memory DataStore layer Be clear
47. Background Threads Main Thread Async Muscles Model/Presenter layer Cortex Business Services layer Be clear
48. Background Threads Cortex Main Thread Async Muscles Model/Presenter layer Business Services layer Use events to return result Each method is available as synch and asynch Thread management is centralized Call methods Return result using events
49. Background Threads Main Thread Async Muscles Model/Presenter layer Cortex Business Services layer Be clear Call methods Create a Runnable Do the job Take a Thread from the pool Return result using events
50. Background Threads Main Thread Async Muscles Model/Presenter layer Cortex Business Services layer Be clear Create a Runnable Do the job Take a Thread from the pool Return result using events /** Should be called from the View */ @Override public void doAStuffAsync(Object object) { getExecutorServiceManager().execute(CANCELLABLE,new DoAStuffRunnable(object)); } Call methods
51. Background Threads Main Thread Async Muscles Model/Presenter layer Cortex Business Services layer Call methods Do the job Take a Thread from the pool Return result using events private class DoAStuffRunnable implements Runnable { private object object; private DoAStuffRunnable(object object) { this.object = object; } @Override public void run() {doAStuff(object);} } Runnable, PoolExecutor, EventBus Create a Runnable
52. Background Threads Main Thread Async Muscles Model/Presenter layer Cortex Business Services layer Call asynchronous methods Create a Runnable Take a Thread from the pool Return result using events @Override public GetDataEvent<Stuff> doAStuff(Object object) { GetDataEvent<Stuff> event=null; try { //make the job and create the event event = new GetDataEvent<Stuff>(BaseEvent.STATUS_SUCCESS, null, stuff, EventType.STUFF); } catch (Exception e) { event = new GetDataEvent<Stuff>(BaseEvent.STATUS_ERROR, Error.fromException(e), null, EventType.STUFF); } finally { eventBus.post(event); } return event; } Runnable, PoolExecutor, EventBus Do the job
53. Background Threads Main Thread Async Muscles Model/Presenter layer Cortex Business Services layer Call methods Create a Runnable Take a Thread from the pool @Subscribe public void onEventStuff(GetDataEvent<Stuff> event) { //Update your data and the view } Runnable, PoolExecutor, EventBus Do the job Return result using events
54. Background Threads Cortex Main Thread Async Muscles Model/Presenter layer No more Thread switch elsewhere Clean, centralized, simple, systematic Call asynchronous methods Return result using events Business Services layer
55. Background Threads , Main Thread Async Makeup View layer Muscles Model/Presenter layer Cortex Business Services layer Memory Local Storage layer Babylon Knowledge Communication layer Conscious memory DataStore layer Call Return result using events
56. More resources Chet Haase (Medium) Developing for Android Colt McAnlis (DevBytes Perfmatters) Android Performance Patterns Season 5 Mathias Seguy DroidConUk 2016 Threatment Architecture Thread Mathias Seguy DevoxxFr 2016 Architecture Android et bonnes pratiques
58. Testing Start by having a strategy
59. How to test that ? Makeup View layer Muscles Model/Presenter layer Cortex Business Services layer Memory Local Storage layer Babylon Knowledge Communication layer Conscious memory DataStore layer
60. Testing Start by having a strategy Unit Tests Instrumented Tests Mock Production Don’t make meaningless tests You have 4 different contexts
61. Testing First context UnitTest + Mock Unit Tests Business Services Test the service and the DataStore D.A.O DataStore Communication Mock Tests
62. Testing Second context UnitTest + Prod Unit Tests Prod Communication layer Test the communication and the D.A.O. layer (integration tests) Local Storage layer Tests Tests use
63. Testing Third context: Instrumented test + Mock Instrumented Tests Mock Model/Presenter Test the View layer Business Services Tests View
64. Testing Fourth context: Instrumented tests + Production Instrumented Tests Prod Test your scenario (acceptance tests) Tests
65. Testing Tests Tests Tests use use Tests use use
66. Testing But wait, how do we change Production by Mock ?
68. Dependencies Injection So Dagger ! https://github.com/google/dagger Based on Module Provide I.O.C. Efficient Complexity drives to bugs I.O.C is a bad Android pattern A nuclear bomb to kill a fly
69. Dependencies Injection Keep simplicity https://github.com/google/dagger Avoid systematic I.O.C. on Android
70. Dependencies Injection Back to the goal D.A.O Communication Business Services ServerManagerMock DaoManagerMock ServiceManagerMoc k Business Services D.A.O. Communication ServerManager DaoManager ServiceManager Prod Mock
71. Dependencies Injection Back to the goal D.A.O Communication Business Services ServerManagerMock DaoManagerMock ServiceManagerMoc k Business Services D.A.O. Communication ServerManager DaoManager ServiceManager Prod Mock
72. Dependencies Injection Use flavors D.A.O Communication Business Services ServerManagerMock DaoManagerMock ServiceManagerMoc k Business Services D.A.O. Communication ServerManager DaoManager ServiceManager Prod Mock public class ServiceInjector { public static IServiceManager getServiceManager(){ if(BaseApplication.getInstance().isServiceManagerExists()){ return BaseApplication.getInstance().getServiceManager(); }else{ return new ServiceManagerMocked(); } } } public class ServiceInjector { public static IServiceManager getServiceManager(){ if(BaseApplication.getInstance().isServiceManagerExists()){ return BaseApplication.getInstance().getServiceManager(); }else{ return new ServiceManager(); } } }
73. Dependencies Injection Use flavors D.A.O Communication Business Services ServerManagerMock DaoManagerMock ServiceManagerMoc k Business Services D.A.O. Communication ServerManager DaoManager ServiceManager Prod Mock
74. Dependencies Injection Be scared of generic and systematic I.O.C. Have a fine grained control on which classes can be injected Make it yourself once Use flavors Using flavors has a side effect: you can build all the flavors Thank Chiuki: http://chiuki.github.io/
76. ManagedException isManaged UserId Error message Technical data Functional data Others stuff Manage exceptions Add information Exception
77. SomeWhere in your code galaxy Manage exceptions Centralize the management Exception Manager ExceptionManager. manage(...) Team FeedBack User FeedBack
78. Manage exceptions The road is long M.V.Architecture
80. Libraries Makeup View layer Muscles Model/Presenter layer Cortex Business Services layer Memory Local Storage layer Babylon Knowledge Communication layer Conscious memory DataStore layer Henson And Dart Retrofit OkHttp/Okio/Moshi android.support.design android.support EventBus android.arch.lifecycle android.arch.persistence And that’s all: Less you have better are you chance of success
81. Libraries Makeup View layer Muscles Model/Presenter layer Cortex Business Services layer Memory Local Storage layer Babylon Knowledge Communication layer Conscious memory DataStore layer Henson And Dart Retrofit OkHttp/Okio/Moshi android.support.design android.support EventBus android.arch.lifecycle android.arch.persistence And that’s all: Less you have better are you chance of sucess You Shall Not Pass
82. Libraries And that’s all: Less you have better are you chance of sucess Good luck with your devs…
83. Libraries And that’s all: Less you have better are you chance of sucess Good luck with your devs… …but stay paranoïac with libs and read this : I’m harvesting credit card numbers and passwords from your site. Here’s how. https://hackernoon.com/im-harvesting-credit-card-numbers-and-passwords-from-your-site-here-s-how-9a8cb347c5b5
85. Where is the SDK ? View layer Models layer Services layer Data layer fundation Use case 1 Use case 2 Use case 3 Use case 4 Use case 5 View layer Models layer Services layer Data layer
86. This is your SDK View layer Models layer Services layer Data layer fundation Use case 1 Use case 2 Use case 3 Use case 4 Use case 5 View layer Models layer Services layer Data layer
87. This is your SDK View layer Models layer Services layer Data layer fundation Exception Management Dependency injection OAuth Request interceptor and RetrofitBuilder PoolExecutors Management 1 second pattern Base View/Activity/ViewModel Base Business services Base events Custom toast/dialog/views Base Application Object Style It contains all your architecture pattern
89. Use Gradle extensively
90. Use Gradle extensively
91. Use Gradle extensively
92. Use Gradle extensively You need tools to analyse your code No Tests, No Reporting Tools, No big vision reports ?
93. Use Gradle extensively You need tools to analyse your code No Tests, No Reporting Tools, No big vision reports ? You are dead
95. Makeup View layer Muscles Model/Presenter layer Cortex Business Services layer Memory Local Storage layer Babylon Knowledge Communication layer Conscious memory DataStore layer Keep it simple
96. Keep it simple Make it scalable fundation Use case 1 Use case 2 Use case 3 Use case 4 Use case 5 View layer Models layer Services layer Data layer View layer Models layer Services layer Data layer
97. Keep it simple Make it scalable Manage Asynchronicity Background Threads Main Thread Muscles Model/Presenter layer Cortex Business Services layer Call Return result using events
98. Keep it simple Make it scalable Manage Asynchronicity Test it Unit Tests Instrumented Tests Mock Production
99. Keep it simple Make it scalable Manage Asynchronicity Test it Manage issues Exception Manager Team FeedBack User FeedBack
100. Keep it simple Make it scalable Manage Asynchronicity Test it Manage issues Have strong fundations fundation View layer Models layer Services layer Data layer
101. Keep it simple Make it scalable Manage Asynchronicity Test it Manage issues Have strong fundations Fears lib
102. Keep it simple Make it scalable Manage Asynchronicity Test it Manage issues Have strong fundations Fears lib Use reporting tools
103. They did it And it works pretty well Sangeetha Santosh Utkarsh Shiva Caroline
104. It takes energy to create excellence. It takes time, It needs convictions. If it was easy, We would all have several Phd.
105. Android by passion Passionate by passing on the knowledge Expert by technical love #android2ee mathias.seguy@android2ee.com www.android2ee.com
106. Thank you! Mathias Seguy @android2ee Slides: http://fr.slideshare.net/Android2EE Code: https://github.com/MathiasSeguy-Android2EE Android2EE http://android2ee.com
107. Thank you! Mathias Seguy Android2EE @android2ee Slides: http://fr.slideshare.net/Android2EE Code: https://github.com/MathiasSeguy-Android2EE Android2EE http://android2ee.com