Difficulties getting Realtime RecyclerView FirebaseUI android to show messages from database

Question

I have been experiencing difficulties getting my Android app's RecyclerView to populate the FirebaseUI adapter with data already in the Firebase database, although I can send data to it using:

public void onAdd(View v){
    //create Firebase Object
    t=(EditText) findViewById(R.id.display);
    String mitems=t.getText().toString();
    myRef.push().setValue(mitems.toString());
}

I used the following with the aim of receiving my sent data but it is not working:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    //Recycler
    recyclerView=(RecyclerView)findViewById(R.id.messageRecyclerView);
    recyclerView.setHasFixedSize(true);
    recyclerView.setLayoutManager(new LinearLayoutManager(this));

    //Adapter
    FirebaseRecyclerAdapter<String, MessageViewHolder> mFirebaseAdapter=
        new FirebaseRecyclerAdapter<String, MessageViewHolder>(
                String.class,
                android.R.layout.simple_list_item_1,
                MessageViewHolder.class,
                myRef.child("Message")
                ) {
                    @Override
                    protected void populateViewHolder(MessageViewHolder viewHolder, String model, int position) {
                        viewHolder.messageTextView.setText(model.toString());
                }
            };
    recyclerView.setAdapter(mFirebaseAdapter);
}

My ViewHolder is defined thus:

static class MessageViewHolder extends RecyclerView.ViewHolder {
    public TextView messageTextView;

    MessageViewHolder(View view) {
        super(view);
        messageTextView = (TextView)view.findViewById(android.R.id.text1);
    }
}

XML:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/messageRecyclerView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"

        />
    <EditText
        android:hint="Enter Text"
        android:id="@+id/display"
        android:textColor="@color/colorAccent"
        android:background="@color/colorPrimary"
        android:padding="10dp"
        android:layout_width="match_parent" android:layout_height="wrap_content"/>
    <Button android:layout_height="wrap_content"
        android:layout_width="match_parent"
        android:text="ADD ITEM"
        android:onClick="onAdd"
        />

</LinearLayout>

Here is The Error Message:

Exception java.lang.ClassCastException: android.support.v7.widget.AppCompatTextView cannot be cast to android.view.ViewGroup
com.firebase.ui.database.FirebaseRecyclerAdapter.onCreateViewHolder (FirebaseRecyclerAdapter.java:160)
android.support.v7.widget.RecyclerView$Adapter.createViewHolder (RecyclerView.java:6073)
android.support.v7.widget.RecyclerView$Recycler.getViewForPosition (RecyclerView.java:5243)
android.support.v7.widget.RecyclerView$Recycler.getViewForPosition (RecyclerView.java:5153)
android.support.v7.widget.LinearLayoutManager$LayoutState.next (LinearLayoutManager.java:2061)
android.support.v7.widget.LinearLayoutManager.layoutChunk (LinearLayoutManager.java:1445)
android.support.v7.widget.LinearLayoutManager.fill (LinearLayoutManager.java:1408)
android.support.v7.widget.LinearLayoutManager.onLayoutChildren (LinearLayoutManager.java:580)
android.support.v7.widget.RecyclerView.dispatchLayoutStep2 (RecyclerView.java:3374)
android.support.v7.widget.RecyclerView.dispatchLayout (RecyclerView.java:3183)
android.support.v7.widget.RecyclerView.consumePendingUpdateOperations (RecyclerView.java:1593)
android.support.v7.widget.RecyclerView$1.run (RecyclerView.java:323)
android.view.Choreographer$CallbackRecord.run (Choreographer.java:788)
android.view.Choreographer.doCallbacks (Choreographer.java:591)
android.view.Choreographer.doFrame (Choreographer.java:559)
android.view.Choreographer$FrameDisplayEventReceiver.run (Choreographer.java:774)
android.os.Handler.handleCallback (Handler.java:808)
android.os.Handler.dispatchMessage (Handler.java:103)
android.os.Looper.loop (Looper.java:193)
android.app.ActivityThread.main (ActivityThread.java:5299)
java.lang.reflect.Method.invokeNative (Method.java)
java.lang.reflect.Method.invoke (Method.java:515)
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run (ZygoteInit.java:829)
com.android.internal.os.ZygoteInit.main (ZygoteInit.java:645)
dalvik.system.NativeStart.main (NativeStart.java)

Answer 1

Replace

        //Adapter
    FirebaseRecyclerAdapter<String, MessageViewHolder> mFirebaseAdapter=
            new FirebaseRecyclerAdapter<String, MessageViewHolder>(
                    String.class,
                    android.R.layout.simple_list_item_1,
                    MessageViewHolder.class,
                    myRef.child("Message")
            )

with

    //Adapter
    FirebaseRecyclerAdapter<String, MessageViewHolder> mFirebaseAdapter=
            new FirebaseRecyclerAdapter<String, MessageViewHolder>(
                    String.class,
                    android.R.layout.simple_list_item_1,
                    MessageViewHolder.class,
                    myRef
            )

Replace myRef.child("Message") with myRef. Based on your onAdd method.

Answer 2

My First attempt at solving this problem was on concentrating on the chuck that i suspected didn't work.From the error message,

Exception 
java.lang.ClassCastException:android.support.v7.widget.AppCompatTextView 
cannot be cast to android.view.ViewGroup 

my best guess was the RecyclerView and its coressponding FirebaseRecyclerAdapter.I replaced it with a ListView and its corresponding FirebaseListAdapter thus:

ListView ml=(ListView) findViewById(R.id.listview);

     FirebaseListAdapter<String> adapter=new FirebaseListAdapter<String>(this,String.class,android.R.layout.simple_list_item_1,myRef.child("Message"))
     {
         @Override
         protected void populateView(View v, String model, int position) {
             TextView tv=(TextView) v.findViewById(android.R.id.text1) ;
             tv.setText(model);

         }
     };
     ml.setAdapter(adapter) ;

The ListView worked; thus confirming that the Firebase database was well formed.I proceeded to re-develop the app with RecyclerView and i realized the first problem (even after successfully cleaning the project) viz:android studio added a version of compile code to my build.graddle file viz: compile 'com.android.support:recyclerview-v7:25.0.0' which was different from my sdk version 24.2.1.Hence i applied the following correction viz:

compile 'com.android.support:recyclerview-v7:24.2.1'

By and large,this correction only stopped the app from crashing but did not solve the problem of displaying my list of data.The following link solved the main problem - casting.The link is a previous question on cast-error-with-firebaserecyclerviewadapter on this platform. So i followed it and it worked.