Android Architecture Componentsで犯しがちな間違い / Common mistakes when using Android Architecture Components

https://proandroiddev.com/5-common-mistakes-when-using-architecture-components-403e9899f4cb
https://note.mu/d_forest/n/n9c2dcf155f34

Transcript

1. Android Architecture Components $ Cooking Programmer
2. Cooking Programmer @d_forest Android Engineer Software Engineer https://prty.jp
3. Android Architecture Components
4. https://proandroiddev.com/5-common-mistakes-when-using-architecture-components-403e9899f4cb
6. https://note.mu/d_forest/n/n9c2dcf155f34
8. Fragment LiveData observer ViewModel Mutable LiveData View ViewModel
9. Fragment LiveData observer
10. class BooksFragment: Fragment() { private lateinit var viewModel: BooksViewModel override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? { return inflater.inflate(R.layout.fragment_books, container) } override fun onActivityCreated(savedInstanceState: Bundle?) { super.onActivityCreated(savedInstanceState) viewModel = ViewModelProviders.of(this).get(BooksViewModel::class.java) viewModel.liveData.observe(this, Observer { updateViews(it) }) } ... }
11. class BooksFragment: Fragment() { private lateinit var viewModel: BooksViewModel override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? { return inflater.inflate(R.layout.fragment_books, container) } override fun onActivityCreated(savedInstanceState: Bundle?) { super.onActivityCreated(savedInstanceState) viewModel = ViewModelProviders.of(this).get(BooksViewModel::class.java) viewModel.liveData.observe(this, Observer { updateViews(it) }) } ... }
12. viewModel.liveData.observe(this, Observer { updateViews(it) }) Activity Fragment e.g. detach onDestroy() Observer Fragment attach/detach Observer
13. viewModel.liveData.observe(viewLifecycleOwner, Observer {... public class Fragment { public LifecycleOwner getViewLifecycleOwner() }
14. class BooksFragment: Fragment() { private lateinit var viewModel: BooksViewModel override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? { return inflater.inflate(R.layout.fragment_books, container) } override fun onActivityCreated(savedInstanceState: Bundle?) { super.onActivityCreated(savedInstanceState) viewModel = ViewModelProviders.of(this).get(BooksViewModel::class.java) viewModel.liveData.observe(viewLifecycleOwner, Observer { updateViews(it) }) } ... }
15. Mutable LiveData View
16. class CatalogueViewModel : ViewModel() { val products = MutableLiveData<Products>() }
17. class CatalogueViewModel : ViewModel() { val products = MutableLiveData<Products>() }
18. val products = MutableLiveData<Products>() View LiveData
19. private val promotions = MutableLiveData<Promotions>() fun getPromotions(): LiveData<Promotions> = promotions private val _offers = MutableLiveData<Offers>() val offers: LiveData<Offers> = _offers OR
20. class CatalogueViewModel : ViewModel() { private val _offers = MutableLiveData<Offers>() val offers: LiveData<Offers> = _offers }
21. THANK YOU!