Data did n't load in firebase app properly

Question

I created an app using firebase on android studio.There is a searchview will appear after authentication with mobile otp. When user search on search view it will filter the resu

Answer 1

All code you have written in onCreateView should be written in onViewCreated.

It's better to do any assignment of subviews to fields in onViewCreated. This is because the framework does an automatic null check for you to ensure that your Fragment's view hierarchy has been created and inflated.

public class FragmentHome extends Fragment {
    private SearchView search;
    View v;
    DatabaseReference dataRef;
    private  FirebaseListAdapter<String> firebaseListAdapter;
    ListView mListView;
    private TextView text;
    ArrayList<String> city=new ArrayList<String>();
    private int i=0;
    private String data,val,var;
    ArrayAdapter<String> adapter;
    ProgressBar progressBar;

    @Nullable
    @Override

    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable final Bundle savedInstanceState) {
        v = inflater.inflate(R.layout.activity_fragment_home,container,false);
        if (container!=null){
            container.removeAllViews();
        }
        return v;
    }

    @Override
    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);

    progressBar= (ProgressBar) v.findViewById(R.id.search_pro);
    search= (SearchView) v.findViewById(R.id.search);
    search.onActionViewExpanded();
    search.setIconified(false);
    search.setInputType(InputType.TYPE_NULL);
    search.setQueryHint("Search Docter By City Or Department");
    mListView= (ListView) v.findViewById(R.id.mList);
    mListView.setVisibility(View.INVISIBLE);

dataRef=FirebaseDatabase.getInstance().getReference().child("Docters");
adapter=new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1, city);
mListView.setAdapter(adapter);
adapter.notifyDataSetChanged();
dataRef.addChildEventListener(new ChildEventListener() {
    @Override
    public void onChildAdded(DataSnapshot dataSnapshot, String s) {
        data=dataSnapshot.child("city").getValue(String.class);
        val=dataSnapshot.child("department").getValue(String.class);
        if (!city.contains(data)){
            city.add(data);
        }
        if (!city.contains(val)){
            city.add(val);
        }
        search.setInputType(InputType.TYPE_CLASS_TEXT);
        progressBar.setVisibility(View.GONE);
        adapter.notifyDataSetChanged();

    }
    @Override
    public void onChildChanged(DataSnapshot dataSnapshot, String s) {
        data=dataSnapshot.child("city").getValue(String.class);
        val=dataSnapshot.child("department").getValue(String.class);
        city.add(data);
        city.add(val);
        city.add(var);
        adapter.notifyDataSetChanged();
    }

    @Override
    public void onChildRemoved(DataSnapshot dataSnapshot) {

    }

    @Override
    public void onChildMoved(DataSnapshot dataSnapshot, String s) {
    }

    @Override
    public void onCancelled(DatabaseError databaseError) {
    }
});
search.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
    @Override
    public boolean onQueryTextSubmit(String text) {

        return false;
    }

    @Override
    public boolean onQueryTextChange(String text) {
        if (!text.isEmpty()){
            adapter.notifyDataSetChanged();
        mListView.setVisibility(View.VISIBLE);
           adapter.getFilter().filter(text);
        }else{
            mListView.setVisibility(View.INVISIBLE);
        }
        return false;
    }

});

mListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        String itemRef = (String) adapter.getItem(position);
        search.setVisibility(View.INVISIBLE);
        mListView.setVisibility(View.INVISIBLE);
        FragmentTransaction ft=getChildFragmentManager().beginTransaction();
        DocterList fragment=new DocterList();
        Bundle item=new Bundle();
        item.putString("item",itemRef);
        fragment.setArguments(item);
        ft.replace(R.id.activity_fragment_home,fragment);
        ft.addToBackStack(null);
        ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
        ft.commit();
    }
});
    }

progressBar= (ProgressBar) v.findViewById(R.id.search_pro); ==> the view will only come into existence in onViewCreated