Android-Read Data From Firebase Real Time Database and Displaying on RecyclerView

Question

I have successfully been able to save data in RTD of Firebase using databaseIngredients.child(StringId).setValue(ingredients); Where the "ingredients" is a String taken from EditText and StringId is a unique ID by the "push" method. I have referred to many tutorials but I am not able to read it, I want to update my RecyclerView every time my database is updated with new data. I just want to display all data in my Database using recyclerView. The ValueEventListener method is not understood by me. Please be patient as I understand the reply, new to Firebase.

**[This](https://stackoverflow.com/questions/49383687/how-can-i-retrieve-data-from-firebase-to-my-adapter/49384849)** is a recommended way in which you can retrieve data from a Firebase Realtime database and display it in a `RecyclerView` using `FirebaseRecyclerAdapter`. — Alex Mamo, Jun 06 '18 at 08:08

score 0 · Accepted Answer · edited Jun 05 '18 at 18:14

Reading data is very simple, all you need to do is set a listener that listens for change in value in the database reference you provided.

There are two listeners for that purpose,

One Time Listener(addListenerForSingleValueEvent), which only reads data once you make request. For this,

DatabaseReference reference = database.getReference("Database").child(StringId).setValue(ingredients);

reference.addListenerForSingleValueEvent(new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
        if(dataSnapShot.exists()){
            //update recyclerview or do anything with your data
        }
    }

    @Override
    public void onCancelled(DatabaseError databaseError) {
        Toast.makeText(getApplicationContext(), databaseError.getMessage(), Toast.LENGTH_SHORT).show();
    }
});

Continuous Data Listener(addValueEventListener), which is used to get data every time it changes in server

DatabaseReference reference = database.getReference("Database").child(StringId).setValue(ingredients);

    reference.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            if(dataSnapShot.exists()){
                //update recyclerview or do anything with your data
            }
        }

        @Override
        public void onCancelled(DatabaseError databaseError) {
            Toast.makeText(getApplicationContext(), databaseError.getMessage(), Toast.LENGTH_SHORT).show();
        }
    });

Thanks for the detailed help, but how will I display my data In the RecyclerView? — , Jun 05 '18 at 17:28
That is very simple too. There are many ways you can do it. This simple example will help you. :) https://www.android-examples.com/show-firebase-database-data-into-recyclerview/ — SafalFrom2050, Jun 12 '18 at 10:26

score 0 · Answer 2 · answered Jun 05 '18 at 19:53

0

You can use FirebaseRecyclerAdapter . You'll need a model class and a ViewHolder class. If you're using new version of firebase-ui then you have to use FirebaseRecyclerOptions along with FirebaseRecyclerAdapter

Here's the official documentation

answered Jun 05 '18 at 19:53

parag pawar

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Android-Read Data From Firebase Real Time Database and Displaying on RecyclerView

2 Answers2