Alejandro Ardavín Alejandro Ardavín - 4 months ago 297
Android Question

How to get a String List from Firebase to fill a Spinner

my database is arranged like this:

enter image description here

I want to get all the values from areaName as a String List or any form of list and use it to populate a Spinner. The problem I am getting is that it only retrieves the last value (in this case "New York"). This is my actual code:

fDatabaseRoot.child("areas").addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot areaSnapshot: dataSnapshot.getChildren()) {
String areaName = areaSnapshot.child("areaName").getValue(String.class);

Spinner areaSpinner = (Spinner) findViewById(R.id.spinner);
final String[] areas = {areaName};
ArrayAdapter<String> areasAdapter = new ArrayAdapter<String>(UAdminActivity.this, android.R.layout.simple_spinner_item, areas);
areasAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
areaSpinner.setAdapter(areasAdapter);
}
}

@Override
public void onCancelled(DatabaseError databaseError) {

}
});

Answer

I don't test that code but, more or less, that is what you have to do:

fDatabaseRoot.child("areas").addValueEventListener(new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
        // Is better to use a List, because you don't know the size 
        // of the iterator returned by dataSnapshot.getChildren() to
        // initialize the array
        final List<String> areas = new ArrayList<String>();

        for (DataSnapshot areaSnapshot: dataSnapshot.getChildren()) {
            String areaName = areaSnapshot.child("areaName").getValue(String.class);
            areas.add(areaName);
        }

        Spinner areaSpinner = (Spinner) findViewById(R.id.spinner);
        ArrayAdapter<String> areasAdapter = new ArrayAdapter<String>(UAdminActivity.this, android.R.layout.simple_spinner_item, areas);
        areasAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        areaSpinner.setAdapter(areasAdapter);
    }

    @Override
    public void onCancelled(DatabaseError databaseError) {

    }
});

I hope it's helps!

Regards.

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