View must have a tag

Question

I have an abstract BaseActivity in my library module:

 @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //Normal method to inflate the layout
        mBinding = DataBindingUtil.setContentView(this, R.layout.base_view_stub_layout);
        AppCompatDelegate.setCompatVectorFromResourcesEnabled(true);
        if (mBinding != null && mBinding.viewStub != null && mBinding.viewStub.getViewStub() != null) {
            mBinding.viewStub.getViewStub().setLayoutResource(getLayoutId());
        }

        if (!hasStubInflated) {
            View inflatedView = mBinding.viewStub.getViewStub().inflate();
            //Abstract method
            onViewStubInflated(inflatedView, savedInstanceState);
            //Normal method to hide progress bar
            onViewStubInflated();
        }
        initControllers();
        handleViews();
        setListeners();
        restoreValues(savedInstanceState);
    }

The MainActivity from AppModule extends the BaseActivity of library module and hence, getting an abstract method to override:

MainActivity extends BaseActivity

private ActivityMainBinding mBinding;

@Override
    public int getLayoutId() {
        return R.layout.activity_main;
    }

@Override
    public void onViewStubInflated(View inflatedView, Bundle savedInstanceState) {
        if (mBinding == null || mBinding.getRoot() != inflatedView) {
            mBinding = ActivityMainBinding.bind(inflatedView);
        }
    }

When I run the app, I am getting:

 Caused by: java.lang.RuntimeException: view must have a tag
        at com.example.android.emailapp.DataBinderMapperImpl.getDataBinder(DataBinderMapperImpl.java:67)
        at androidx.databinding.MergedDataBinderMapper.getDataBinder(MergedDataBinderMapper.java:74)
        at androidx.databinding.DataBindingUtil.bind(DataBindingUtil.java:199)
        at androidx.databinding.ViewDataBinding.bind(ViewDataBinding.java:693)
        at com.example.android.emailapp.databinding.ActivityMainBinding.bind(ActivityMainBinding.java:99)
        at com.example.android.emailapp.databinding.ActivityMainBinding.bind(ActivityMainBinding.java:87)
        at com.example.android.emailapp.login.MainActivity.onViewStubInflated(MainActivity.java:86)
        at com.library.android.common.ui.baseui.BaseActivity.onCreate(BaseActivity.java:52)

Note that I have layout tag in both xml of BaseActivity and MainActivity.

I have tried this with no success.

Is mBinding.viewStub.getViewStub().setLayoutResource(getLayoutId()) an issue in BaseActivity as it will try to get the layout from AppModule? if it is that, how can I solve it?

If you know the answer, please try to explain why this is happening along with the solution...

Already tried

View must have a tag error

What does it mean by view must have a tag error

How to use databinding for viewstub

Answer 1

If you are using the custom class as the root view of your_layout.xml then you must override all constructors of view

your class

class MyCustomView : FrameLayout {
    constructor(context: Context) : super(context){
        ...
    }

    constructor(context: Context, attrs: AttributeSet?) : super(context, attrs){
        ...
    }
    constructor(context: Context, attrs: AttributeSet?, defStyleAttr: Int) : super(context, attrs, defStyleAttr){
        ...
    }
}

your layout

<layout xmlns:android="http://schemas.android.com/apk/res/android">
    <data>
        <variable name="viewModel" type="......" />
    </data>

    <MyCustomView
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    </MyCustomView>

</layout>

Answer 2

You must wrap your viewStub's layouts with <layout></layout> as well, which is what they are expecting : Either using DataBinding everywhere, or simply nowhere.

---

If you don't want DataBinding on the viewStub, then extra work needs to be done.

For example if itemData is the DataBindingImpl object for my listview, and I am to inflate some sort of more options overlay-ViewStub, then I need to store the inflated view myself, and avoid accessing the `mRoot field of the DataBinding's ViewStubProxy

ViewGroup inflated = (ViewGroup) itemData.someView.getTag();
if(inflated==null) {
    ViewStub stub = itemData.viewStubProxy.getViewStub();
    if(stub!=null) {
        stub.setOnInflateListener(null);
        inflated = (ViewGroup) stub.inflate();
        // what I need is simply to set onClickListener on all of it's children. (one for-loop inside)
        Utils.setOnClickListenersOneDepth(inflated, onClickListener, 3, null);
        itemData.someView.setTag(inflated);
    }
}
if(inflated!=null) {
    // what I need then is to animate the overlay. 
    View mRoot = inflated;
    int width = itemData.getRoot().getWidth();
    mRoot.setAlpha(0);
    mRoot.setTranslationX(width/3);
    mRoot.animate().alpha(1);
    mRoot.animate().translationX(0);
}

Never invoke itemData.viewStubProxy.getViewStub().getRoot()、.isInflated() or so because we are now storing the inflated outside of the DataBindingImpl object.