Cleanup RTDB Paging demo for consistency

app/src/main/AndroidManifest.xml

@@ -59,7 +59,7 @@
         <!-- Realtime database paging demo -->
         <activity
             android:name=".database.realtime.FirebaseDbPagingActivity"
-            android:label="@string/title_paging_database_activity" />
+            android:label="@string/title_realtime_database_paging_activity" />
 
         <activity
             android:name=".database.realtime.RealtimeDbChatIndexActivity"

app/src/main/java/com/firebase/uidemo/ChooserActivity.java

@@ -82,7 +82,7 @@ private static class ActivityChooserAdapter
                 R.string.title_firestore_activity,
                 R.string.title_firestore_paging_activity,
                 R.string.title_realtime_database_activity,
-                R.string.title_paging_database_activity,
+                R.string.title_realtime_database_paging_activity,
                 R.string.title_storage_activity
         };
 
@@ -92,7 +92,7 @@ private static class ActivityChooserAdapter
                 R.string.desc_firestore,
                 R.string.desc_firestore_paging,
                 R.string.desc_realtime_database,
-                R.string.desc_paging_database,
+                R.string.desc_realtime_database_paging,
                 R.string.desc_storage
         };
 

app/src/main/java/com/firebase/uidemo/database/firestore/FirestorePagingActivity.java

@@ -118,7 +118,7 @@ protected void onLoadingStateChanged(@NonNull LoadingState state) {
 
     @Override
     public boolean onCreateOptionsMenu(@NonNull Menu menu) {
-        getMenuInflater().inflate(R.menu.menu_firestore_paging, menu);
+        getMenuInflater().inflate(R.menu.menu_paging, menu);
         return true;
     }
 

app/src/main/java/com/firebase/uidemo/database/realtime/FirebaseDbPagingActivity.java

@@ -10,6 +10,8 @@
 import android.support.v7.widget.RecyclerView;
 import android.util.Log;
 import android.view.LayoutInflater;
+import android.view.Menu;
+import android.view.MenuItem;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.TextView;
@@ -23,6 +25,8 @@
 import com.google.firebase.database.FirebaseDatabase;
 import com.google.firebase.database.Query;
 
+import java.util.Locale;
+
 import butterknife.BindView;
 import butterknife.ButterKnife;
 
@@ -36,6 +40,7 @@ public class FirebaseDbPagingActivity extends AppCompatActivity {
     @BindView(R.id.swipe_refresh_layout)
     SwipeRefreshLayout mSwipeRefreshLayout;
 
+    private FirebaseDatabase mDatabase;
     private Query mQuery;
 
     @Override
@@ -44,7 +49,8 @@ protected void onCreate(@Nullable Bundle savedInstanceState) {
         setContentView(R.layout.activity_database_paging);
         ButterKnife.bind(this);
 
-        mQuery = FirebaseDatabase.getInstance().getReference().child("posts");
+        mDatabase = FirebaseDatabase.getInstance();
+        mQuery = mDatabase.getReference().child("items");
 
         setUpAdapter();
     }
@@ -59,27 +65,27 @@ private void setUpAdapter() {
                 .build();
 
         //Initialize Firebase Paging Options
-        DatabasePagingOptions<Post> options = new DatabasePagingOptions.Builder<Post>()
+        DatabasePagingOptions<Item> options = new DatabasePagingOptions.Builder<Item>()
                 .setLifecycleOwner(this)
-                .setQuery(mQuery, config, Post.class)
+                .setQuery(mQuery, config, Item.class)
                 .build();
 
         //Initializing Adapter
-        final FirebaseRecyclerPagingAdapter<Post, PostViewHolder> mAdapter =
-                new FirebaseRecyclerPagingAdapter<Post, PostViewHolder>(options) {
+        final FirebaseRecyclerPagingAdapter<Item, ItemViewHolder> mAdapter =
+                new FirebaseRecyclerPagingAdapter<Item, ItemViewHolder>(options) {
                     @NonNull
                     @Override
-                    public PostViewHolder onCreateViewHolder(@NonNull ViewGroup parent,
+                    public ItemViewHolder onCreateViewHolder(@NonNull ViewGroup parent,
                                                              int viewType) {
                         View view = LayoutInflater.from(parent.getContext())
-                                .inflate(R.layout.item_post, parent, false);
-                        return new PostViewHolder(view);
+                                .inflate(R.layout.item_item, parent, false);
+                        return new ItemViewHolder(view);
                     }
 
                     @Override
-                    protected void onBindViewHolder(@NonNull PostViewHolder holder,
+                    protected void onBindViewHolder(@NonNull ItemViewHolder holder,
                                                     int position,
-                                                    @NonNull Post model) {
+                                                    @NonNull Item model) {
                         holder.bind(model);
                     }
 
@@ -90,26 +96,23 @@ protected void onLoadingStateChanged(@NonNull LoadingState state) {
                             case LOADING_MORE:
                                 mSwipeRefreshLayout.setRefreshing(true);
                                 break;
-
                             case LOADED:
                                 mSwipeRefreshLayout.setRefreshing(false);
                                 break;
-
                             case FINISHED:
                                 mSwipeRefreshLayout.setRefreshing(false);
-                                Toast.makeText(getApplicationContext(), getString(R.string.paging_finished_message), Toast.LENGTH_SHORT).show();
+                                showToast(getString(R.string.paging_finished_message));
                                 break;
-
                             case ERROR:
-                                retry();
+                                showToast(getString(R.string.unknown_error));
                                 break;
                         }
                     }
 
                     @Override
                     protected void onError(DatabaseError databaseError) {
                         mSwipeRefreshLayout.setRefreshing(false);
-                        Log.e(TAG, databaseError.getMessage());
+                        Log.e(TAG, databaseError.getDetails(), databaseError.toException());
                     }
                 };
 
@@ -126,35 +129,71 @@ public void onRefresh() {
         });
     }
 
-    public static class Post {
 
-        @Nullable public String title;
-        @Nullable public String body;
+    @Override
+    public boolean onCreateOptionsMenu(@NonNull Menu menu) {
+        getMenuInflater().inflate(R.menu.menu_paging, menu);
+        return true;
+    }
+
+    @Override
+    public boolean onOptionsItemSelected(@NonNull MenuItem item) {
+        if (item.getItemId() == R.id.item_add_data) {
+            showToast("Adding data...");
+            createItems();
+            return true;
+        }
+        return super.onOptionsItemSelected(item);
+    }
+
+    @NonNull
+    private void createItems() {
+        for (int i = 0; i < 250; i++) {
+            String title = "Item " + i;
 
-        public Post(){}
+            String id = String.format(Locale.getDefault(), "item_%03d", i);
+            Item item = new Item(title, i);
 
-        public Post(@Nullable String title, @Nullable String body) {
-            this.title = title;
-            this.body = body;
+            mDatabase.getReference("items").child(id).setValue(item);
         }
     }
 
-    public static class PostViewHolder extends RecyclerView.ViewHolder {
+    private void showToast(@NonNull String message) {
+        Toast.makeText(this, message, Toast.LENGTH_SHORT).show();
+    }
+
+
+    public static class Item {
+
+        @Nullable
+        public String text;
+        public int value;
+
+        public Item(){}
+
+        public Item(@Nullable String text, int value) {
+            this.text = text;
+            this.value = value;
+        }
+    }
+
+    public static class ItemViewHolder extends RecyclerView.ViewHolder {
+
 
-        @BindView(R.id.textViewTitle)
-        TextView mTitleView;
+        @BindView(R.id.item_text)
+        TextView mTextView;
 
-        @BindView(R.id.textViewBody)
-        TextView mBodyView;
+        @BindView(R.id.item_value)
+        TextView mValueView;
 
-        PostViewHolder(@NonNull View itemView) {
+        ItemViewHolder(@NonNull View itemView) {
             super(itemView);
             ButterKnife.bind(this, itemView);
         }
 
-        void bind(@NonNull Post post) {
-            mTitleView.setText(post.title);
-            mBodyView.setText(post.body);
+        void bind(@NonNull Item item) {
+            mTextView.setText(item.text);
+            mValueView.setText(String.valueOf(item.value));
         }
     }
 

app/src/main/res/layout/activity_database_paging.xml

@@ -16,6 +16,6 @@
         android:paddingLeft="16dp"
         android:paddingTop="8dp"
         android:paddingRight="16dp"
-        tools:listitem="@layout/item_post" />
+        tools:listitem="@layout/item_item" />
 
 </android.support.v4.widget.SwipeRefreshLayout>

app/src/main/res/values/strings.xml

@@ -2,19 +2,19 @@
     <string name="app_name">Firebase UI</string>
 
     <!-- Chooser -->
-    <string name="title_auth_activity">Auth UI demo</string>
+    <string name="title_auth_activity">Auth UI Demo</string>
     <string name="title_firestore_activity">Cloud Firestore Demo</string>
     <string name="title_firestore_paging_activity">Cloud Firestore Paging Demo</string>
-    <string name="title_realtime_database_activity">Real-time database demo</string>
-    <string name="title_paging_database_activity">Paging database demo</string>
+    <string name="title_realtime_database_activity">Realtime Database Demo</string>
+    <string name="title_realtime_database_paging_activity">Realtime Database Paging Demo</string>
     <string name="title_storage_activity">Storage Image Demo</string>
 
     <string name="desc_auth">Demonstrates the Firebase Auth UI flow, with customization options.</string>
     <string name="desc_anonymous_upgrade">Demonstrates upgrading an anonymous account using FirebaseUI.</string>
     <string name="desc_firestore">Demonstrates using a FirestoreRecyclerAdapter to load data from Cloud Firestore into a RecyclerView for a basic chat app.</string>
     <string name="desc_firestore_paging">Demonstrates using a FirestorePagingAdapter to load/infinite scroll paged data from Cloud Firestore.</string>
     <string name="desc_realtime_database">Demonstrates using a FirebaseRecyclerAdapter to load data from Firebase Database into a RecyclerView for a basic chat app.</string>
-    <string name="desc_paging_database">Demonstrates using a FirebaseRecyclerPagingAdapter to load/infinite scroll paged data from Firebase Database.</string>
+    <string name="desc_realtime_database_paging">Demonstrates using a FirebaseRecyclerPagingAdapter to load/infinite scroll paged data from Firebase Realtime Database.</string>
     <string name="desc_storage">Demonstrates displaying an image from Cloud Storage using Glide.</string>
 
     <!-- Auth UI -->
@@ -120,8 +120,6 @@
     <string name="start_chatting">No messages. Start chatting at the bottom!</string>
     <string name="signing_in">Signing in…</string>
     <string name="signed_in">Signed In</string>
-    <string name="post_text_title">Title</string>
-    <string name="post_text_body">Body</string>
     <string name="anonymous_auth_failed_msg">
         Anonymous authentication failed, various components of the demo will not work.
         Make sure your device is online and that Anonymous Auth is configured in your Firebase project

database/src/main/java/com/firebase/ui/database/paging/FirebaseDataSource.java

@@ -34,9 +34,9 @@ public class FirebaseDataSource extends PageKeyedDataSource<String, DataSnapshot
     private final MutableLiveData<LoadingState> mLoadingState = new MutableLiveData<>();
     private final MutableLiveData<DatabaseError> mError = new MutableLiveData<>();
 
-    private static final String STATUS_DATABASE_NOT_FOUND = "DATABASE NOT FOUND";
-    private static final String MESSAGE_DATABASE_NOT_FOUND = "Database not found at given child path !";
-    private static final String DETAILS_DATABASE_NOT_FOUND = "Database Children Not Found in the specified child path. Please specify correct child path/reference";
+    private static final String STATUS_DATABASE_NOT_FOUND = "DATA_NOT_FOUND";
+    private static final String MESSAGE_DATABASE_NOT_FOUND = "Data not found at given child path!";
+    private static final String DETAILS_DATABASE_NOT_FOUND = "No data was returned for the given query: ";
 
     private Runnable mRetryRunnable;
 
@@ -214,10 +214,11 @@ private String getLastPageKey(@NonNull List<DataSnapshot> data) {
     }
 
     private void setDatabaseNotFoundError(){
+        String details = DETAILS_DATABASE_NOT_FOUND + mQuery.toString();
         mError.postValue(DatabaseError.fromStatus(
                 STATUS_DATABASE_NOT_FOUND,
-                DETAILS_DATABASE_NOT_FOUND,
-                MESSAGE_DATABASE_NOT_FOUND));
+                MESSAGE_DATABASE_NOT_FOUND,
+                details));
 
         mLoadingState.postValue(LoadingState.ERROR);
     }