Trying to run method in a layout file from my view model but, I keep getting error: cannot find symbol class ViewModels
from my layout file. The layout file is a fragment. I tried invalidating the cache and resyncing but, it did not help. Do i need to add anything to the fragment itself? I seen people use data binding to launch the fragment but, I've read its optional.
Update: Took out OnClick method to test and it is still throwing error. I guess the problem is with my deceleration but, idk why. When i am editing the layout the path shows up when I type the view model name in.
Update2: Tried setting type in variable equal to path of activity that launches fragment for testing and it built just fine. There must be a way to add an import that is not my activity.
Layout file
<?xml version="1.0" encoding="utf-8"?>
<layout>
<data>
<variable
name="viewTest"
type="rangers.socmanv2.ViewModels.BattleRhythmViewModel" />
</data>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/battleRhythmMenu"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".Fragments.BattleRhythmFrag">
<Button
android:id="@+id/newBattle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="76dp"
android:layout_marginLeft="76dp"
android:layout_marginTop="88dp"
android:text="New Battle Rhythm"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
/>
<Button
android:id="@+id/editBattle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="76dp"
android:layout_marginLeft="76dp"
android:layout_marginTop="50dp"
android:text="Edit Battle Rhythm"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/newBattle" />
<Button
android:id="@+id/deleteBattle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="76dp"
android:layout_marginLeft="76dp"
android:layout_marginTop="50dp"
android:text="Delete Battle Rhythm"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/editBattle" />
</android.support.constraint.ConstraintLayout>
</layout>
Fragment
public class BattleRhythmFrag extends Fragment {
private BattleRhythmViewModel mViewModel;
private View view;
private Button test;
public static BattleRhythmFrag newInstance() {
return new BattleRhythmFrag();
}
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container,
@Nullable Bundle savedInstanceState) {
view = inflater.inflate(R.layout.battle_rhythm_fragment, container, false);
mViewModel = new BattleRhythmViewModel();
return view;
}
@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
mViewModel = ViewModelProviders.of(this).get(BattleRhythmViewModel.class);
// TODO: Use the ViewModel
}
}
View model
public class BattleRhythmViewModel extends ViewModel {
public void launchNewFragment(FragmentManager fragM)
{
Log.d("viewmodel","hitting launchNewFrag");
HomeFrag test = new HomeFrag();
fragM.beginTransaction().replace(R.id.homeContent,test,"launched"+test);
}
public void test()
{Log.d("viewmodel","hitting test");
}
}
Your error is in viewModel
constructor.
you must add a default constructor beacuse you don't added any factory ViewModelProvider.Factory
but your BattleRhythmViewModel
dosen't have any default constructor.
ANSWER 1:
public class BattleRhythmViewModel extends ViewModel {
public void launchNewFragment(){
}
public void test()
{Log.d("viewmodel","hitting test");
}
}
}
ANSWER 2: better than answer 1 beacuse you don't need add default and can use your fragment in model
public class Factory implements ViewModelProvider.Factory {
private FragmentManager fragM;
public Factory(FragmentManager fragM) {
this.fragM= fragM;
}
@NonNull
@Override
public <T extends ViewModel> T create(@NonNull Class<T> modelClass) {
if (modelClass.isAssignableFrom(BattleRhythmViewModel.class)) {
return (T) new BattleRhythmViewModel(fragM);
}
throw new IllegalArgumentException("Unknown ViewModel class");
}
}
change your viewmodel creator line to
Factory factory = new Factory(this)
mViewModel = ViewModelProviders.of(this,factory).get(BattleRhythmViewModel.class);