[Blog post] ລອງຫຼິ້ນ Firebase Realtime Database ກັບ Android

[app] build.gradle

dependencies {
    // version ອາດມີການປ່ຽນແປງໃນອະນາຄົດ
    compile 'com.google.firebase:firebase-core:9.4.0'
    compile 'com.google.firebase:firebase-database:9.4.0'
}
// ເພີ່ມໃສ່ລຸ່ມສຸດຂອງໄຟລ໌
apply 'com.google.gms:google-services'

[project] build.gradle

buildscript {
    dependencies {
        classpath 'com.google.gms:google-services:3.0.0'
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.khatthaphone.firebasedatabase.MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/condition"
        android:text="ສະພາບອາກາດ" />
</RelativeLayout>

Database Rules.json

{
  "rules": {
    ".read": true,
    ".write": "auth != null"
  }
}

MainActivity.java

// your package name here / ໃສ່ຊື່ package ຂອງເຈົ້າເອງ

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
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 {
    TextView textView;

    DatabaseReference mDatabaseRef = FirebaseDatabase.getInstance().getReference();
    DatabaseReference mConditionRef = mDatabaseRef.child("condition");

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

        textView = (TextView) findViewById(R.id.condition);

    }

    @Override
    protected void onStart() {
        super.onStart();

        mConditionRef.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                String text = dataSnapshot.getValue(String.class);
                textView.setText(text);
            }

            @Override
            public void onCancelled(DatabaseError databaseError) {

            }
        });
    }
}