Menggunakan Database Firebase 2 -Android

Gambar 1. Logo Firebase

Halaman ini merupakan lanjutan dari halaman

https://komputasistat.blogspot.co.id/2017/03/menggunakan-database-firebase-1-android.html

Pada halaman sebelumnya sudah share mengenai register aplikasi ke firebase, saat ini saya akan share source code aplikasi.

MainActivity.java:

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.text.TextUtils;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

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;

public class MainActivity extends AppCompatActivity {

    private static final String TAG = MainActivity.class.getSimpleName();
    private TextView txtDetails;
    private EditText inputName, inputEmail;
    private Button btnSave;
    private DatabaseReference mFirebaseDatabase;
    private FirebaseDatabase mFirebaseInstance;

    private String userId;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Displaying toolbar icon
        getSupportActionBar().setDisplayShowHomeEnabled(true);
        getSupportActionBar().setIcon(R.mipmap.ic_launcher);

        txtDetails = (TextView) findViewById(R.id.txt_user);
        inputName = (EditText) findViewById(R.id.name);
        inputEmail = (EditText) findViewById(R.id.email);
        btnSave = (Button) findViewById(R.id.btn_save);

        mFirebaseInstance = FirebaseDatabase.getInstance();

        // get reference to 'users' node
        mFirebaseDatabase = mFirebaseInstance.getReference("users");

        // store app title to 'app_title' node
        mFirebaseInstance.getReference("app_title").setValue("Realtime Database");

        // app_title change listener
        mFirebaseInstance.getReference("app_title").addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                Log.e(TAG, "App title updated");

                String appTitle = dataSnapshot.getValue(String.class);

                // update toolbar title
                getSupportActionBar().setTitle(appTitle);
            }

            @Override
            public void onCancelled(DatabaseError error) {
                // Failed to read value
                Log.e(TAG, "Failed to read app title value.", error.toException());
            }
        });

        // Save / update the user
        btnSave.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String name = inputName.getText().toString();
                String email = inputEmail.getText().toString();

                // Check for already existed userId
                if (TextUtils.isEmpty(userId)) {
                    createUser(name, email);
                } else {
                    updateUser(name, email);
                }
            }
        });

        toggleButton();
    }

    // Changing button text
    private void toggleButton() {
        if (TextUtils.isEmpty(userId)) {
            btnSave.setText("Save");
        } else {
            btnSave.setText("Update");
        }
    }

    /**
     * Creating new user node under 'users'
     */
    private void createUser(String name, String email) {
        // TODO
        // In real apps this userId should be fetched
        // by implementing firebase auth
        if (TextUtils.isEmpty(userId)) {
            userId = mFirebaseDatabase.push().getKey();
        }

        User user = new User(name, email);

        mFirebaseDatabase.child(userId).setValue(user);

        addUserChangeListener();
    }

    /**
     * User data change listener
     */
    private void addUserChangeListener() {
        // User data change listener
        mFirebaseDatabase.child(userId).addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                User user = dataSnapshot.getValue(User.class);

                // Check for null
                if (user == null) {
                    Log.e(TAG, "User data is null!");
                    return;
                }

                Log.e(TAG, "User data is changed!" + user.name + ", " + user.email);

                // Display newly updated name and email
                txtDetails.setText(user.name + ", " + user.email);

                // clear edit text
                inputEmail.setText("");
                inputName.setText("");

                toggleButton();
            }

            @Override
            public void onCancelled(DatabaseError error) {
                // Failed to read value
                Log.e(TAG, "Failed to read user", error.toException());
            }
        });
    }

    private void updateUser(String name, String email) {
        // updating the user via child nodes
        if (!TextUtils.isEmpty(name))
            mFirebaseDatabase.child(userId).child("name").setValue(name);

        if (!TextUtils.isEmpty(email))
            mFirebaseDatabase.child(userId).child("email").setValue(email);
    }
}

User.java:

package com.example.windows.insertdatabase;

/**
 * Created by Windows on 29/03/2017.
 */
import com.google.firebase.database.IgnoreExtraProperties;

@IgnoreExtraProperties
public class User {

    public String name;
    public String email;

    // Default constructor required for calls to
    // DataSnapshot.getValue(User.class)
    public User() {
    }

    public User(String name, String email) {
        this.name = name;
        this.email = email;
    }
}

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
 >

    <TextView
        android:id="@+id/txt_user"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"

        android:textSize="20dp" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">



            <EditText
                android:id="@+id/name"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:inputType="textCapWords"
                android:maxLines="1" />



            <EditText
                android:id="@+id/email"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:inputType="textEmailAddress"
                android:maxLines="1" />


        <Button
            android:id="@+id/btn_save"
            style="?android:textAppearanceSmall"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="16dp"
            android:background="@color/colorPrimary"

            android:textColor="@android:color/white"
            android:textStyle="bold" />

    </LinearLayout>

</LinearLayout>

jangan lupa pada firebase console  atur rule:

Gambar 2. Atur rule akses database

akhir aplikasi :

Gambar 3. Akhir aplikasi

Sekian dan Terima kasih

Silahkan request tutorial lainya

Artikel Terkait Android ,Firebase