FirebaseReclycerView не отображается

Question

У меня есть FirebaseReclycerView, который не отображается на экране. У меня есть следующий возврат в журнале:

E/RecyclerView: адаптер не прилагается; пропуская макет

Вот коды деятельности:

public class HistoricActivity extends CommonActivity{ 
private static final String TAG = HistoricActivity.class.getSimpleName(); 
private String id, reference; 
private boolean typeUser; 
private TextView tvNoHistoric; 
private ImageView ivHistoric; 
private RecyclerView rvHistoric; 
private HistoricAdapter adapter; 
private CardView cardView; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_historic); 
    Intent it = getIntent(); 
    params = it.getExtras(); 
    if (params != null) { 
     id = params.getString("id"); 
     typeUser = params.getBoolean("type"); 
    } 
    initViews(); 
} 

@Override 
protected void onResume() { 
    super.onResume(); 
    loadHistoric(); 
} 

private void loadHistoric() { 
    openProgressBar(); 
    if (typeUser){ 
     reference = "bakeries"; 
    } else { 
     reference = "users"; 
    } 
    mDatabaseReference.child(reference).child(id).addListenerForSingleValueEvent(new ValueEventListener() { 
     @Override 
     public void onDataChange(DataSnapshot dataSnapshot) { 
      if (dataSnapshot.hasChild("historic")) { 
       closeProgressBar(); 
       if (tvNoHistoric.getVisibility() == View.VISIBLE) { 
        tvNoHistoric.setVisibility(View.GONE); 
       } 
       if (ivHistoric.getVisibility() == View.VISIBLE) { 
        ivHistoric.setVisibility(View.GONE); 
       } 
       cardView.setVisibility(View.VISIBLE); 
       adapter = new HistoricAdapter(mDatabaseReference.child(reference).child(id).child("historic").getRef(), 
         HistoricActivity.this 
       ) {}; 
       rvHistoric.setHasFixedSize(true); 
       rvHistoric.setItemAnimator(new DefaultItemAnimator()); 
       rvHistoric.setLayoutManager(new LinearLayoutManager(HistoricActivity.this)); 
       rvHistoric.addItemDecoration(new DividerItemDecoration(HistoricActivity.this)); 
       rvHistoric.setAdapter(adapter); 
      } else { 
       closeProgressBar(); 
       tvNoHistoric.setVisibility(View.VISIBLE); 
       ivHistoric.setVisibility(View.VISIBLE); 
       cardView.setVisibility(View.INVISIBLE); 
      } 
     } 

     @Override 
     public void onCancelled(DatabaseError databaseError) { 
      Log.w(TAG, "getUser:onCancelled", databaseError.toException()); 
     } 
    }); 
} 

@Override 
protected void initViews() { 
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar_historic); 
    setSupportActionBar(toolbar); 
    setTitle("Histórico"); 
    getSupportActionBar().setDisplayHomeAsUpEnabled(true); 
    getSupportActionBar().setDisplayShowHomeEnabled(true); 
    tvNoHistoric = (TextView) findViewById(R.id.tv_no_historic); 
    progressBar = (ProgressBar) findViewById(R.id.simpleProgressBar); 
    ivHistoric = (ImageView) findViewById(R.id.ic_historic); 
    rvHistoric = (RecyclerView) findViewById(R.id.rv_historic); 
    cardView = (CardView) findViewById(R.id.card_historic); 
} 

@Override 
public boolean onOptionsItemSelected(MenuItem item) { 
    switch (item.getItemId()) { 
     case android.R.id.home: 
      onBackPressed(); 
      return true; 
    } 
    return super.onOptionsItemSelected(item); 
} 
} 

адаптер:

public class HistoricAdapter extends FirebaseRecyclerAdapter<Historic, HistoricViewHolder> { 
private static final String TAG = HistoricAdapter.class.getSimpleName(); 
private Context mContext; 

public HistoricAdapter(Query ref, Context context) { 
    super(Historic.class, R.layout.item_historic, HistoricViewHolder.class, ref); 
    this.mContext = context; 
} 

@Override 
protected void populateViewHolder(final HistoricViewHolder viewHolder, final Historic model, final int position) { 
    viewHolder.tvData.setText(model.getDate()); 
    viewHolder.tvMsg.setText(model.getMsg()); 
} 
} 

ViewHolder:

public class HistoricViewHolder extends RecyclerView.ViewHolder{ 

public TextView tvData, tvMsg; 

public HistoricViewHolder(View v){ 
    super(v); 
    tvData = (TextView) itemView.findViewById(R.id.tv_data); 
    tvMsg = (TextView) itemView.findViewById(R.id.tv_msg); 
} 
} 

XML:

<LinearLayout 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:layout_width="match_parent" 
android:layout_height="match_parent" 
android:background="#CFCFCF" 
android:orientation="vertical" 
tools:context=".activity.HistoricActivity"> 

<android.support.design.widget.AppBarLayout 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:theme="@style/AppTheme.AppBarOverlay"> 

    <android.support.v7.widget.Toolbar 
     android:id="@+id/toolbar_historic" 
     android:layout_width="match_parent" 
     android:layout_height="?attr/actionBarSize" 
     android:background="?attr/colorPrimary" 
     app:popupTheme="@style/AppTheme.PopupOverlay" /> 

</android.support.design.widget.AppBarLayout> 

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

    <RelativeLayout 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content"> 

     <ProgressBar 
      android:id="@+id/simpleProgressBar" 
      android:layout_width="60sp" 
      android:layout_height="60sp" 
      android:layout_centerHorizontal="true" 
      android:layout_centerVertical="true" 
      android:visibility="invisible" /> 

     <ImageView 
      android:id="@+id/ic_historic" 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_alignParentTop="true" 
      android:layout_centerInParent="true" 
      android:layout_marginTop="40dp" 
      android:src="@drawable/ic_history_black_36dp" 
      android:visibility="invisible" /> 

     <com.devspark.robototextview.widget.RobotoTextView 
      android:id="@+id/tv_no_historic" 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_alignParentTop="true" 
      android:layout_centerInParent="true" 
      android:layout_marginTop="100dp" 
      android:text="@string/no_historic" 
      android:textColor="@color/black_50_opacity" 
      android:textSize="15sp" 
      android:visibility="invisible" 
      app:typeface="roboto_light_italic" /> 

     <android.support.v7.widget.CardView 
      android:id="@+id/card_historic" 
      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:layout_width="match_parent" 
      android:layout_height="wrap_content" 
      android:layout_marginLeft="8dp" 
      android:layout_marginRight="8dp" 
      android:layout_marginTop="8dp" 
      android:elevation="4dp" 
      android:visibility="invisible" 
      app:cardCornerRadius="2dp"> 

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

     </android.support.v7.widget.CardView> 

    </RelativeLayout> 
</RelativeLayout> 

Answer 1

Вы должны инициализировать и установить пустой адаптер в вашем методе OnCreate(). Все это должно быть в ваших initViews() метод:

adapter = new HistoricAdapter(mDatabaseReference.child(reference).child(id).child("historic").getRef(), 
        HistoricActivity.this 
      ) {}; 
      rvHistoric.setHasFixedSize(true); 
      rvHistoric.setItemAnimator(new DefaultItemAnimator()); 
      rvHistoric.setLayoutManager(new LinearLayoutManager(HistoricActivity.this)); 
      rvHistoric.addItemDecoration(new DividerItemDecoration(HistoricActivity.this)); 
      rvHistoric.setAdapter(adapter); 

Ваш initViews() запускаемых перед тем loadHistoric(), так что есть небольшой момент, когда нет переходника прилагается.