android-livedata

I created live data which emits a single event as in this example . My question is next: How to notify only last subscribed observer when the value in the LiveData changes? What comes to my mind is to store observers in the linked list in SingleLiveData class and then to call super.observe only if a passed observer is the same as the last element of the list. I'm not sure if this is the best approach. I want to use this mechanism to propagate FAB click events from activity to the fragments which are shown inside of the ViewPager. Fragments are dynamically added to view pager adapter, so let's

I try to test some methods on my Application but I get an error when calling mutablelivedata.postValue. Here is a snippet and the error message: @Test public void callStartScreenRepository(){ Observer<User> userObserver = mock(Observer.class); startScreenViewModel.returnUser().observeForever(userObserver); maennlich = new User(); maennlich.setVorname("Christian"); MutableLiveData<User> userTest = new MutableLiveData<>(); userTest.postValue(maennlich); when(startScreenRepository.userWebService("testUser")).thenReturn(userTest); verify(userObserver).onChanged(maennlich); } java.lang

How can I do databinding with livedata? activity_user_detail.xml: <data> <variable name="viewModel" type="com.test.viewmodel.UserViewModel" /> </data> <TextView android:id="@+id/tv_amount" android:layout_width="match_parent" android:text="@{viewModel.age}" .... UserViewModel.java: public class UserViewModel extends ViewModel { public LiveData<User> user; public void getUserById(UserDao userDao, String userId){ transaction = UserDao .load(userId); } } UserDao.java: @Query("SELECT * FROM `user` WHERE id = :userId") LiveData<User> load(String userId); UserDetailActivity.java: private

I'm working on a project in android for a udacity course I'm currently trying to implement a search function while adhering to android architecture components and using firestore and room I'm fairly new to all these concepts so please point out anything that seems wrong. So I made a database repository to keep my firestore and room databases in sync and to deliver the data. I'm then using viewmodel and the observer pattern (I think) so my observer gets the data and looks for changes gives it to my adapter ( refreshMyList(List) ) which populates a recyclerview like this : contactViewModel =

I found that the LiveData returned by Dao will call its observer whenever the row is updated in DB, even if the LiveData value is obviously not changed. Consider a situation like the following example : Example entity @Entity public class User { public long id; public String name; // example for other variables public Date lastActiveDateTime; } Example Dao @Dao public interface UserDao { // I am only interested in the user name @Query("SELECT name From User") LiveData<List<String>> getAllNamesOfUser(); @Update(onConflict = OnConflictStrategy.REPLACE) void updateUser(User user); } Somewhere in

How do I remove the observer after I receive the first result? Below are two code ways I've tried, but they both keep receiving updates even though I have removed the observer. Observer observer = new Observer<DownloadItem>() { @Override public void onChanged(@Nullable DownloadItem downloadItem) { if(downloadItem!= null) { DownloadManager.this.downloadManagerListener.onDownloadManagerFailed(null, "this item already exists"); return; } startDownload(); model.getDownloadByContentId(contentId).removeObservers((AppCompatActivity)context); } }; model.getDownloadByContentId(contentId).observeForever

What is the best practice for using the MediatorLiveData with multiple sources? I have a MediatorLiveData in the ViewModel, that is accessed from the view for the data, that should finally be presented. The MediatorLiveData depends on multiple other LiveDatas. Some of them come from the repository layer, some of them have to be processed in the ViewModel before they can be accessed from the MediatorLiveData and some of them come from the View. So my current implementation looks like the following schema: public MyViewModel extends ViewModel { LiveData<Foo> liveData1; LiveData<Bar> liveData2;