Winning with Android Architecture

Transcript

1. Nosakhare Belvi, Intelia @kingsmentor Uyo Winning With Android Architecture
2. What is the Hardest Part of Android Development ? Managing LifeCycle
3. Dealing with Android LifeCycle
4. Android Architecture Component Why : What: • Best practices and guidelines for building Android Apps • Solves the build problem of lifecycle • Independent Set of Components • Very powerful when used all together • Recommended way/pattern of building Android apps
5. Main Android Architecture Component #DevFest2018
6. Dealing with Android LifeCycle Now. Eas Sim c
7. // in your project level build,gradle allProjects{ repositories{ jcenter() google() } } // In your app level build.gradle // For LifeCycles , ViewModels, LiveData compile “android.arch.lifecycle:runtime:1.1.1” compile “android.arch.lifecycle:extensions.1.1” // Others can also go here Add Architecture Component to your app
8. Model View ViewModel (MVVM) Approach ViewModel Repository Network DataBase View Model Room
9. #DevFest2018 LifeData<T> An observable data holder that is Lifecycle aware and does automatic management of Subscriptions
10. // Without LifeData @Query (“SELECT * FROM” + TABLE ) List<Movie> fetchData(); // With LifeData @Query (“SELECT * FROM” + TABLE ) LiveData<List<Movie>> fetchData(); Wrap response object into a LiveData Yo h e c t i w ve wa t c re t n e //observe on the UI repository.fetchData().observe(this, new Observer<List<Item>>(){ @Override public void onChange(@Nullable List<Item> item){ // stream of changes } });
11. What if... • Configuration change • User Behaviour • Add anything that bothers you about lifecycle here
12. #DevFest2018 ViewModel • Data Survives configuration changes • No leaks (no reference to activities,fragment or views) • Store and manage UI related data
13. ViewModel Scope
14. Worthy of Notes: #DevFest2018 • VMs can be shared between UI Components • VMs are not persisted if the application is killed by the OS • Use Sparingly - Don’t o l a t mu d
15. Create a ViewModel public class ItemViewModel extends ViewModel{ private LiveData<List<Item>> items; public ItemViewModel(){ // Do not work on the main thread items = ItemRepository.getInstance().loadAll(); } } public LiveData<List<Event>> getItems() { return items};
16. Get the ViewModel public void Oncreate(Bundle savedInstanceState){ super.Oncreate(sacedInstanceState); // Get the VM. // this ties this View model to the lifeCycler. It refers to the lifeCycle Owner // in this case, an Activity. viewModel = ViewModelProdiders.of(this).get(ItemViewModel.class); }
17. LifeCycle & LifeCycle Aware Components • Interfaces that let you build aware component • Automatically adjust behavior according to the current lifecycle • Helps avoid memory leaks and complex activity/fragment code
18. Handling LifeCycle public class ItemActivity extends AppCompactActivity { public void OnStart(){ videoPlayer.start(); // initialise other items } public void OnStart(){ videoPlayer.start(); // clear up resources } } public class ItemComponent implements LifeCycleObserver { @OnLifeCycleEvent(Lifecycle.Event.On_START) public void OnStart(){ // do something } // OR DO THIS public void enable(){ if (lifecycle.getState().isAtLeast(STARTED)){ // do something } } } The y The O Way
19. Add observe to a LifecycleOwner public class ItemActivity extends LifecycleActivity { @Override public void OnCreate(@Nullable Bundle savedInstanceState){ super.onCreate(savedInstanceState); getLifeCycle().addObserver(new ItemComponent()); } }
20. #DevFest2018 LifeCycleOwner Interface with method to define that a component has a Lifecycle
21. Example of a Lifecycle Owner public class ItemActivity extends LifecycleActivity { @Override public void OnCreate(@Nullable Bundle savedInstanceState){ super.onCreate(savedInstanceState); getLifeCycle().addObserver(new ItemComponent()); } }
22. • Architecture Component are a welcome addition to Android • Helps solve complex problem especially with handling lifecycles management • Helps mitigate memory leaks and exceptions due to being in the incorrect state • Simple, readable and maintainable code.
23. Other Architecture Component #DevFest2018
24. #DevFest2018 Quick Reminder They can work individually and they mix well together. Use these arsenals to build better apps.
25. Best Coding Practices #DevFest2018 • Avoid work when possible ◦ Use recommended libraries (also contribute) • Profile your code • Use Support Libraries Features • Minimize memory consumption Al a s R be • Dev ar o r -co t ed • Bat y e s ti • Ban d s ec u • Use p i c a t
26. Catching up with Android Trends #DevFest2018 • Follow the right people on twitter (especially experts like Jake Wharton, Romain Guy, Ian Lake, Chris Bane) • Android developer blog • Android developer site • Android Weekly • Watch talks from Google.io (If you weren’t invited or can’t afford to go) • Follow Android Developer Channel on Youtube • Android dev summit (livestream or watch videos after summit) • Popular Github repo or projects from rockstar devs on Android. • Blogs of Android dev Experts e.g ProAndroidDev, castle.io
27. Helpful Resources #DevFest2018 • https://www.youtube.com/watch?v=IrMw7MEgADk • https://www.youtube.com/watch?v=iDH84_OMPmw • https://www.youtube.com/watch?v=7p22cSzniBM • https://proandroiddev.com/mvvm-architecture-viewmodel-and-livedata-part-1-604f50cda1 • https://developer.android.com/studio/profile/android-profiler?gclid=CjwKCAiAiarfBRASEiwAw1tYv-z3dH8CMm C7c0AErrP_CgXoATVDI8HC8rtmwmsiXYfwlt29gwMLsBoC6nMQAvD_BwE • https://developer.android.com/jetpack/ • https://developer.android.com/topic/libraries/architecture/ • https://www.youtube.com/watch?v=7ll-rkLCtyk • https://github.com/uber/okbuck
28. Nosakhare Belvi, Intelia @kingsmentor Uyo Thank you!