Android architecture component

Android architecture component - LifeCycleEvent , LiveData and ViewModel session Presented at Simform Solution

Transcript

1. Why we been here to discuss ? Aren't we making a great code ?
2. • Handling lifecycle event • Crashes due to stopped activities • Memory leak • Handling configuration changes • boilerplate code Common problems
3. Solution ? Architecture Components
4. • LifecycleOwner • LifecycleObserver • ProcessLifecycle • Livedata • ViewModel • Saving state • Room Components
5. Let’s dive in Boom…!!
6. Lifecycle Events
7. LiveData<T> • observable data holder
 (LiveData is an observable data holder class.) • lifecycle-aware observable
 (Unlike a regular observable, LiveData is lifecycle-aware, meaning it respects the lifecycle of other app components, such as activities, fragments, or services) • Manage Subscription itself
 (LiveData only notifies to active observer only if it’s activity state in STARTED or RESUMED)
8. LiveData Methods • onActive()
 The onActive() method is called when the LiveData object has an active observer. This means you need to start observing the CRYPTO PRICE updates from this method. • onInactive()
 The onInactive() method is called when the LiveData object doesn't have any active observers. Since no observers are listening, there is no reason to stay connected to the CRYPTO MANAGER service. • setValue(T)
 The setValue(T) method updates the value of the LiveData instance and notifies any active observers about the change. • postValue(T)
 The postValue(T) method works similarly as setValue(T) but this method useful while in worker/ background thread.
9. Working With LiveData
10. Current API Call
11. What is issue with this ? • Manually handling lifecycle event • memory leak • Unnecessary use of data pack
12. Let’s implement LiveData
13. Let’s implement LiveData
14. Let’s implement LiveData
15. Let’s implement LiveData
16. LifeCycle Monitor Activity Created OnCreate API Call OnStart OnResume Activity Recreated OnCreate API Call OnStart OnResume Rotate Device OnPause OnStop OnDestroy
17. LifeCycle Monitor Activity Created OnCreate API Call OnStart OnResume Activity Recreated OnCreate API Call OnStart OnResume Rotate Device OnPause OnStop OnDestroy
18. Is this good solution ?
19. Yes Is this good solution ?
20. Yes Is this good solution ? Will there be memory leak ?
21. Yes Is this good solution ? Will there be memory leak ? No
22. Yes Is this good solution ? Will there be memory leak ? No Can we make better ?
23. Yes Is this good solution ? Will there be memory leak ? No Can we make better ? Yes
24. But what is the problem ?
25. Problem Activity Created OnCreate API Call OnStart OnResume Activity Recreated OnCreate API Call OnStart OnResume Rotate Device OnPause OnStop OnDestroy 2 API CALL
26. Solution Activity Created OnCreate API Call OnStart OnResume Activity Recreated OnCreate API Call OnStart OnResume Rotate Device OnPause OnStop OnDestroy
27. ViewModel • Viewmodel class is designed to store and manage UI-related data in a lifecycle conscious way. • Viewmodel can save large data as compare to onSavedInstance(). • it can survive configuration changes. • clear automatically when activity destroyed • don’t reference your view inside view model • Now it can be GOAL KEEPER to call an APIs.
28. LifeCycle of Viewmodel
29. Implementation of Viewmodel
30. Implementation of Viewmodel
31. Implementation of Viewmodel
32. Implementation of Viewmodel
33. Thank You Hope you enjoy the show