How to Implement Search for a Registered User Functionality in Social Media Android App?

This is the Part 9 of “Build a Social Media App on Android Studio” tutorial, and we are going to cover the following functionalities in this article:

• We are going to Search For a user on the Users Page.
• If there are few people registered in our app then it is easy to search for a person.
• But what happens when we have 1000 users registered in our app then searching for a particular user became a very complicated and time taking task.
• That’s why we are implementing this feature to search for a user using the name or email provided.

Step By Step Implementation

Step 1: Working with the main_menu.xml file

Add the Search icon in the main_menu.xml file.

XML

<item
  android:id="@+id/search"
  android:icon="@drawable/ic_search"
  android:title="Search"
  app:actionViewClass="android.widget.SearchView"
  app:showAsAction="always">
</item>

Step 2: Working with the UsersFragment.java file

Add the searchusers() in this file.

Java

private void searchusers(final String s) {
        final FirebaseUser firebaseUser = FirebaseAuth.getInstance().getCurrentUser();
        DatabaseReference reference = FirebaseDatabase.getInstance().getReference("Users");
        reference.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                usersList.clear();
                for (DataSnapshot dataSnapshot1 : dataSnapshot.getChildren()) {
                    ModelUsers modelUsers = dataSnapshot1.getValue(ModelUsers.class);
                    if (!modelUsers.getUid().equals(firebaseUser.getUid())) {
                        if (modelUsers.getName().toLowerCase().contains(s.toLowerCase()) ||
                                modelUsers.getEmail().toLowerCase().contains(s.toLowerCase())) {
                            usersList.add(modelUsers);
                        }
                    }
                    adapterUsers = new AdapterUsers(getActivity(), usersList);
                    adapterUsers.notifyDataSetChanged();
                    recyclerView.setAdapter(adapterUsers);
                }

            }

            @Override
            public void onCancelled(@NonNull DatabaseError databaseError) {

            }
    });
}

Below is the updated code for the UsersFragment.java file.

Java

package com.example.socialmediaapp;

import android.os.Bundle;
import android.text.TextUtils;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.SearchView;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.core.view.MenuItemCompat;
import androidx.fragment.app.Fragment;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;

import java.util.ArrayList;
import java.util.List;

/**
 * A simple {@link Fragment} subclass.
 */
public class UsersFragment extends Fragment {

    RecyclerView recyclerView;
    AdapterUsers adapterUsers;
    List<ModelUsers> usersList;
    FirebaseAuth firebaseAuth;

    public UsersFragment() {
        // Required empty public constructor
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View view = inflater.inflate(R.layout.fragment_users, container, false);
        recyclerView = view.findViewById(R.id.recyclep);
        recyclerView.setHasFixedSize(true);
        recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
        usersList = new ArrayList<>();
        firebaseAuth = FirebaseAuth.getInstance();
        getAllUsers();
        return view;
    }

    private void getAllUsers() {
        final FirebaseUser firebaseUser = FirebaseAuth.getInstance().getCurrentUser();
        DatabaseReference reference = FirebaseDatabase.getInstance().getReference("Users");
        reference.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                usersList.clear();
                for (DataSnapshot dataSnapshot1 : dataSnapshot.getChildren()) {
                    ModelUsers modelUsers = dataSnapshot1.getValue(ModelUsers.class);
                    if (modelUsers.getUid() != null && !modelUsers.getUid().equals(firebaseUser.getUid())) {
                        usersList.add(modelUsers);
                    }
                    adapterUsers = new AdapterUsers(getActivity(), usersList);
                    recyclerView.setAdapter(adapterUsers);
                }

            }

            @Override
            public void onCancelled(@NonNull DatabaseError databaseError) {

            }
        });
    }

    private void searchusers(final String s) {
        final FirebaseUser firebaseUser = FirebaseAuth.getInstance().getCurrentUser();
        DatabaseReference reference = FirebaseDatabase.getInstance().getReference("Users");
        reference.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                usersList.clear();
                for (DataSnapshot dataSnapshot1 : dataSnapshot.getChildren()) {
                    ModelUsers modelUsers = dataSnapshot1.getValue(ModelUsers.class);
                    if (modelUsers.getUid() != null && !modelUsers.getUid().equals(firebaseUser.getUid())) {
                        if (modelUsers.getName().toLowerCase().contains(s.toLowerCase()) ||
                                modelUsers.getEmail().toLowerCase().contains(s.toLowerCase())) {
                            usersList.add(modelUsers);
                        }
                    }
                    adapterUsers = new AdapterUsers(getActivity(), usersList);
                    adapterUsers.notifyDataSetChanged();
                    recyclerView.setAdapter(adapterUsers);
                }

            }

            @Override
            public void onCancelled(@NonNull DatabaseError databaseError) {

            }
        });
    }

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        setHasOptionsMenu(true);
        super.onCreate(savedInstanceState);
    }

    @Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
        inflater.inflate(R.menu.main_menu, menu);
        menu.findItem(R.id.logout).setVisible(false);
        MenuItem item = menu.findItem(R.id.search);
        SearchView searchView = (SearchView) MenuItemCompat.getActionView(item);
        searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextSubmit(String query) {
                if (!TextUtils.isEmpty(query.trim())) {
                    searchusers(query);
                } else {
                    getAllUsers();
                }
                return false;
            }

            @Override
            public boolean onQueryTextChange(String newText) {
                if (!TextUtils.isEmpty(newText.trim())) {
                    searchusers(newText);
                } else {
                    getAllUsers();
                }
                return false;
            }
        });

        super.onCreateOptionsMenu(menu, inflater);
    }

}

Output:

For all the drawable file used in this article please refer to this link: https://drive.google.com/drive/folders/1M_knOH_ugCuwSP5nkYzeD4dRp-Honzbe?usp=sharing

Below is the file structure after performing these operations: