Develop Reference

How to read data from RecyclerView and make comparison?

Hi I want to read the display data from RecyclerView and make comparison.
This my layout for the activity:
What I want to do is to read all data from RecyclerView and compare with Daily Calorie Suggestion.
After reading all data, I need to make comparisons on how many times the user have taken above, less or sufficient total calories as shown in the "Analysis of Total Calories Consumed of Last 7 Days"
The code:
#Override
protected void onStart() {
Query query = ref.orderByChild("timeStamp").limitToLast(7).endAt(Date);
super.onStart();
if (query != null) {
query .addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
if (dataSnapshot.exists()) {
userHighlights = new ArrayList<>();
for (DataSnapshot ds : dataSnapshot.getChildren()) {
userHighlights.add(ds.getValue(HighightsModel.class));
requiredCalorieRef = FirebaseDatabase.getInstance().getReference("Users").child(FirebaseAuth.getInstance().getCurrentUser().getUid());
requiredCalorieRef.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
String userCalorieSuggestion = String.valueOf((dataSnapshot.child("daily calorie").getValue()));
int daily_calorie = Integer.parseInt(userCalorieSuggestion);
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
}
});
}
HighlightsAdapter highlightsAdapter = new HighlightsAdapter(userHighlights);
highlightsRV.setAdapter(highlightsAdapter);
}
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
Toast.makeText(UserNewHighlights.this, databaseError.getMessage(),
Toast.LENGTH_SHORT).show();
}
});
}
}
This is my firebase:
Do I have to write a new code to solve this problem or else? Any help will be much appreciated. Thanks

As #MasoudDarzi mentioned, it's not related to the RecyclerView.
You can try something like this:
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
if (dataSnapshot.exists()) {
userHighlights = new ArrayList<>();
for (DataSnapshot ds : dataSnapshot.getChildren()) {
userHighlights.add(ds.getValue(HighightsModel.class));
requiredCalorieRef = FirebaseDatabase.getInstance().getReference("Users").child(FirebaseAuth.getInstance().getCurrentUser().getUid());
requiredCalorieRef.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
String userCalorieSuggestion = String.valueOf((dataSnapshot.child("daily calorie").getValue()));
int daily_calorie = Integer.parseInt(userCalorieSuggestion);
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
}
});
}
HighlightsAdapter highlightsAdapter = new HighlightsAdapter(userHighlights);
highlightsRV.setAdapter(highlightsAdapter);
// do calculation here with userHighlights
int countExceeded = 0, countBelow = 0, countSufficient = 0;
for (HighightsModel h : userHighlights) {
if (h.totalCalorie > daily_calorie) {
countExceeded++;
} else if (h.totalCalorie < daily_calorie) {
countBelow++;
} else {
countSufficient++;
}
}
// update your TextView with the count numbers
// todo
}
}

so The brute force solution is to have a for in your data after getting the 7 days average.
for (your 7 days data){
// check if your data is lower or higher than the average
// and store number of higher or lower
}
looking for a better solution?

I have solved my problem by adding another child at History node. Whereby, previously I have only these for History :
but I add new child which is called STATUS, the status is updated from previous activity as seen the pic below:
so what I did for the code is :
private void upDateAnalysisAbove() {
DatabaseReference ref = FirebaseDatabase.getInstance().getReference("History");
DatabaseReference mRef = ref.child(FirebaseAuth.getInstance().getCurrentUser().getUid());
Query mQuery = mRef.orderByChild("status").equalTo("ABOVE").limitToLast(7);
mQuery.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
String value = String.valueOf(dataSnapshot.getChildrenCount());
int values = Integer.parseInt(value);
txt_above_output.setText(values + " times(s)");
upDateAnalysisLess(values);
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
//LESS
private void upDateAnalysisLess(int values) {
DatabaseReference ref = FirebaseDatabase.getInstance().getReference("History");
DatabaseReference mRef = ref.child(FirebaseAuth.getInstance().getCurrentUser().getUid());
Query mQuery = mRef.orderByChild("status").equalTo("LESS").limitToFirst(7);
mQuery.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
String valueLess = String.valueOf(dataSnapshot.getChildrenCount());
int values_Less = Integer.parseInt(valueLess);
if (values_Less == 0){
txt_less_output.setText(values_Less + " times(s)");
}
if (values > values_Less){
int finalCount = values - values_Less ;
txt_less_output.setText(finalCount + " times(s)");
}
if (values <values_Less){
int finalCount = values_Less - values ;
txt_less_output.setText(finalCount + " times(s)");
}
updateSuff();
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
//SUFFICIENT
private void updateSuff() {
DatabaseReference ref = FirebaseDatabase.getInstance().getReference("History");
DatabaseReference mRef = ref.child(FirebaseAuth.getInstance().getCurrentUser().getUid());
Query mQuery = mRef.orderByChild("status").equalTo("SUFFICIENT").limitToFirst(7);
mQuery.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
String value = String.valueOf(dataSnapshot.getChildrenCount());
int suffValue = Integer.parseInt(value);
if (suffValue == 0) {
txt_sufficient_output.setText(suffValue + " times(s)");
}
if (suffValue != 0){
txt_sufficient_output.setText(suffValue + " times(s)");
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
Here is the output:
credit to this post that helped me a lot, and thanks for those who tried to help me.

Firebase User Chat Rating - Android

First of all, I'm a real beginner in Android and want to learn.
I want to rate a user who responded to my initiated message using firebase. So only once can the user who initiated the conversation
rate the other user, but only after the response ( first response, no matter what response, even if it is just "hi")
He can receive any amount of ratings (positive or negative) but from different users), in my case, I add/subtract 10 for every vote.
My Firebase DB structure looks like this:
Layout:
I have tried this way, but haven't succeeded:
if (FirebaseAuth.getInstance().getCurrentUser() != null) {
messageRef = mRootRef.child("messages")
.child(mCurrentUserId)
.child(mChatUser);
chatRef = mRootRef.child("chat")
.child(mCurrentUserId)
.child(mChatUser);
final Query convQuery = chatRef;
convQuery.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
Conv conversation = dataSnapshot.getValue(Conv.class);
convVoted = conversation.isVoted();
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
Query messageCheckQuery = messageRef.orderByKey();
messageCheckQuery.addChildEventListener(new ChildEventListener() {
#Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
Messages message = dataSnapshot.getValue(Messages.class);
final String messageKey = dataSnapshot.getKey();
String messageTo = message.getTo();
voteBoolean = message.isVoted();
if (!messageTo.equals(mCurrentUserId)) {
ratingLayout.setVisibility(View.GONE);
} else {
if (!convVoted) {
ratingLayout.setVisibility(View.VISIBLE);
Query query = mRootRef.child("user_account_settings")
.orderByKey()
.equalTo(mChatUser);
query.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
DataSnapshot singleSnapshot = dataSnapshot.getChildren().iterator().next();
UserInfo userInfo = singleSnapshot.getValue(UserInfo.class);
voteNumberStr = userInfo.getMessage_rating();
Log.d("RATING", " Voted : " + convVoted + " | Rating Number : " + voteNumberStr);
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
mVoteUpBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
voteNumber = Integer.parseInt(voteNumberStr);
voteNumber = voteNumber + 10;
voteNumberStr = String.valueOf(voteNumber);
convVoted = true;
//voteBoolean = true;
mRootRef.child("messages")
.child(mCurrentUserId)
.child(mChatUser)
.child(messageKey)
.child("voted").setValue(true);
mRootRef.child("chat")
.child(mCurrentUserId)
.child(mChatUser)
.child("voted").setValue(true);
mRootRef.child("user_account_settings")
.child(mChatUser)
.child("message_rating").setValue(voteNumberStr);
Log.d("RATING", " clicked : " + convVoted + " | Rating Number : " + voteNumberStr);
ratingLayout.setVisibility(View.GONE);
}
});
mVoteDownBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
voteNumber = voteNumber - 10;
voteNumberStr = String.valueOf(voteNumber);
//voteBoolean = true;
convVoted = true;
mRootRef.child("messages")
.child(mCurrentUserId)
.child(mChatUser)
.child(messageKey)
.child("voted").setValue(true);
mRootRef.child("chat")
.child(mCurrentUserId)
.child(mChatUser)
.child("voted").setValue(true);
mRootRef.child("user_account_settings")
.child(mChatUser)
.child("message_rating").setValue(voteNumberStr);
Log.d("RATING", " clicked : " + convVoted + " | Rating Number : " + voteNumberStr);
ratingLayout.setVisibility(View.GONE);
}
});
} else
{
ratingLayout.setVisibility(View.GONE);
}
}
}
#Override
public void onChildChanged(DataSnapshot dataSnapshot, String s) {
}
#Override
public void onChildRemoved(DataSnapshot dataSnapshot) {
}
#Override
public void onChildMoved(DataSnapshot dataSnapshot, String s) {
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
ANY HELP WOULD BE MUCH APPRECIATED.

if i understood your problem i do this way, i perform the rating only on message click, i think is the best way.
remove the bottom rate.
eg

How can I compare this 2 value then show to FirebaseRecyclerAdapter?

I want to connect the user id with the same key in Users, then show the key to FirebaseRecyclerAdapter. I get the key in Friend child already but don't know how to match this to Users.
And my code:
mFriendList = FirebaseDatabase.getInstance().getReference().child("Friends").child(current_id);
mFriendDatabase = FirebaseDatabase.getInstance().getReference().child("Users");
mFriendList.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot snapshot : dataSnapshot.getChildren()) {
String sd = snapshot.getKey(); //key from Friends
final FirebaseRecyclerAdapter<Users_Friends, UsersFriendViewHolder> firebaseRecyclerAdapter =
new FirebaseRecyclerAdapter<Users_Friends, UsersFriendViewHolder>(
Users_Friends.class,
R.layout.users_single_friend_layout,
UsersFriendViewHolder.class,
filter
) {
#Override
protected void populateViewHolder(UsersFriendViewHolder viewHolder, Users_Friends users, int position) {
viewHolder.setDisplayName(users.getName());
viewHolder.setStatusUsers(users.getStatus());
viewHolder.setUserImage(users.getImage(), getContext().getApplicationContext());
final String user_id = getRef(position).getKey();
viewHolder.mView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent profileIntent = new Intent(getActivity(), ProfileActivity.class);
profileIntent.putExtra("user_id", user_id);
startActivity(profileIntent);
}
});
}
};
mReqList.setAdapter(firebaseRecyclerAdapter);
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});

You only need to use exists() method directly on the dataSnapshot object like this:
ValueEventListener eventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
if(dataSnapshot.child(current_id).exists()) {
Log.d("TAG", "User exists");
} else {
Log.d("TAG", "User does not exist");
}
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
mFriendDatabase.addListenerForSingleValueEvent(eventListener);

How to show an error message when email val is not available in firebase database

My Firebase Database is look like as bellow:
I want to show an error message when email val is not available in firebase database.
And my code is
mRef.orderByChild("email").equalTo(val).addChildEventListener(new ChildEventListener() {
#Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
User user = dataSnapshot.getValue(User.class);
textView.setText("Welcome " + user.name );
System.out.println(user.name + "\n" + user.email + "\n" + user.tell);
}
#Override
public void onChildChanged(DataSnapshot dataSnapshot, String s) {
User user = dataSnapshot.getValue(User.class);
textView.setText("Welcome " + user.name );
System.out.println(user.name + "\n" + user.email + "\n" + user.tell);
}
#Override
public void onChildRemoved(DataSnapshot dataSnapshot) {
}
#Override
public void onChildMoved(DataSnapshot dataSnapshot, String s) {
}
#Override
public void onCancelled(FirebaseError firebaseError) {
}
});

A ChildEventListener can only detect the presence of a certain child node or when a child node is changed/removed. It cannot detect the absence of a child. To detect that there is no value, you need a ValueEventListener:
mRef.orderByChild("email").equalTo(val).addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
if (dataSnapshot.getChildrenCount() == 0) {
System.out.println("No user with email "+val);
}
}
#Override
public void onCancelled(FirebaseError firebaseError) {
throw firebaseError.toException(); // don't ignore onCancelled!
}
});

mQuery = databaseReference.limitToLast(1).orderByChild("email").equalTo(category);
mQuery.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
Log.i(TAG, "onDataChange: "+dataSnapshot.toString());
GenericTypeIndicator<Map<String,UserModel>> t=new GenericTypeIndicator<Map<String,UserModel>>(){};
try{
Map<String,UserModel> userList=dataSnapshot.getValue(t);
}catch(Exception exception){
//Error UserInfo not present in firebase
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
//Error wile accessing database
}
});

Android RecycleView does not show data in list

this.books = new ArrayList<>();
mFirebaseDatabaseReference.child(SellBooksPost).addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange( DataSnapshot AdataSnapshot) {
for (final DataSnapshot AmessageSnapshot : AdataSnapshot.getChildren()) {
bFirebaseDatabaseReference.child(mUserId).addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot BdataSnapshot) {
for (DataSnapshot BmessageSnapshot : BdataSnapshot.getChildren()) {
if (BmessageSnapshot.child("book").getValue().toString().equals(AmessageSnapshot.child("SellBooksPostId").getValue().toString())){
Log.d("INFO", "SELL BOOK book " + BmessageSnapshot.child("book").getValue());
Log.d("INFO", "SELL BOOK DETAIL " + AmessageSnapshot.child("SellBooksPostId").getValue());
books.add(new Book(
AmessageSnapshot.child("SellBooksPostId").getValue().toString(),
AmessageSnapshot.child("bookTitle").getValue().toString()
));
}
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
saleBookPostAdapter = new SaleBookPostAdapter(getApplicationContext(), books);
mRoomRecyclerView.setHasFixedSize(true);
mRoomRecyclerView.setAdapter(saleBookPostAdapter);

It's hard to say if this is a problem, but I do not see a call to RecyclerView.Adapter#notifyDataSetChanged() method after updating the data. So try call
salesBookAdapter.notifyDataSetChanged()
after
books.add(new Book(
AmessageSnapshot.child("SellBooksPostId").getValue().toString(),
AmessageSnapshot.child("bookTitle").getValue().toString()
));