Create Push Notifications Using Google Cloud Messaging PHP and MySQL in Android

Introduction

Google Cloud Messaging for Android (GCM): Helps the developer send data from servers and send data to our application. In other words when we send the request to the server then server returns a response to your application whenever new data is available instead of making a request to the server in a timely fashion.

Introduction to Google cloud messaging PHP and MySQL

This tutorial uses PHP as the server-side programming language and MySQL as the server-side database. The flow is provided by Android Google cloud Messaging.

Step 1

First an Android device sends its device id (sender id) to the GCM server for registration.

Step 2

When the registration is successfull the GCM Server returns a registration id to the Android device.

Step 3

After successfully receiving the registration id the device will send the registration id to our server.

Step 4

Store the registration id into the database.

Registering with Google Cloud Messaging.

Creating MySQL Database

1. Open the phpmyadmin panel by going to http://localhost/phpmyadmin and create a database called GCM.
   
   
2. Creating the database, select the database and execute the following query in the SQL tab to create the gcm_pushnotification_users table.
   

   CREATE TABLE IF NOT EXISTS `gcm_pushnotification_users ` (
   `id` int(11) NOT NULL AUTO_INCREMENT,
   `gcm_regid` text,
   `name` varchar(50) NOT NULL,
   `email` varchar(255) NOT NULL,
   `created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
   PRIMARY KEY (`id`)
   ) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;

Creating the PHP Project

Click on the xammp icon in the system tray then select PHP -> PHP Extensions -> Enable php_curl.

1. Go to your xammp folder and inside the htdocs folder create a folder called gcm_server_php.
   
   
2. Create a field called database_config.php. This field holds the database configuration and Google API key.
   
   database_config.php
   

   <?php
      /**
      * Database config variables
      */
      define("DB_HOST", "localhost");
      define("DB_USER", "root");
      define("DB_PASSWORD", "");
      define("DB_DATABASE", "pushnotification");
      /*
      * Google API Key
      */
      define("GOOGLE_API_KEY", "BIzajiCRLa4LjkiuytloQBcRCYcIVYA45048i9i8zfClqc"); // Place your Google API Key
   ?>

3. Create another file called database_connect.php. This file handles database connections and mainly opens and closes the connection.
   
   b_connect.php
   

   <?php
      class Database_Connect.{
      // Connecting to database
      public function connect() {
      require_once database_config.php ';
      // connecting to mysql
      $con = mysql_connect(DB_HOST, DB_USER, DB_PASSWORD);
      // selecting database
      mysql_select_db(DB_DATABASE);
      // return database handler
      return $con;
      }
         // Closing database connection
        public function close() {
         mysql_close();
      }
   }
   ?>

4. Create functions.php. This file contains the function to do database CRUD operations.
   
   functions.php
   

   <?php
      class Functions {
         private $db;
         //put your code here
         // constructor
         function __construct() {
            include_once './database_connect.php';
            // connecting to database
            $this->db = new Database_Connect();
            $this->db->connect();
         }
         // destructor
         function __destruct() {
         }
         /**
         * Storing new user
         * returns user details
         */
         public function storeUser($name, $email, $gcm_regid) {
            // insert user into database
            $result = mysql_query("INSERT INTO gcm_pushnotification_users (name, email, gcm_regid, created_at) VALUES('$name', '$email', '$gcm_regid', NOW())");
            // check for successful store
            if ($result) {
               // get user details
               $id = mysql_insert_id(); // last inserted id
               $result = mysql_query("SELECT * FROM gcm_pushnotification_users WHERE id = $id") or die(mysql_error());
               // return user details
               if (mysql_num_rows($result) > 0) {
                  return mysql_fetch_array($result);
               } else {
                  return false;
               }
               } else {
                  return false;
               }
            }
            /**
            * Getting all users
            */
            public function getAllUsers() {
               $result = mysql_query("select * FROM gcm_pushnotification_users ");
               return $result;
            }
         }
   ?>

5. Create GCM.php. This file sends push notification requests to the GCM server.
   
   GCM.php
   

   <?php
      class GCM {
         /**
         * Sending Push Notification
         */
         public function send_notification($registatoin_ids, $message) {
            // include config
            include_once './database_connect.php';
            $url = 'https://android.googleapis.com/gcm/send';
            $fields = array(
            'registration_ids' => $registatoin_ids,
            'data' => $message,
            );
            $headers = array(
            'Authorization: key=' . GOOGLE_API_KEY,
            'Content-Type: application/json'
            );
            // Open connection
            $ch = curl_init();
            curl_setopt($ch, CURLOPT_URL, $url);
            curl_setopt($ch, CURLOPT_POST, true);
            curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
            curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
            curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($fields));
            $result = curl_exec($ch);
            if ($result === FALSE) {
            die('Curl failed: ' . curl_error($ch));
         }
         // Close connection
         curl_close($ch);
         echo $result;
         }
      }
   ?>

6. Create a register_user.php file. This file is used to receive requests from the Android device and stores the user in the database.
   
   register_user.php
   

   <?php
      $json = array();
      /**
      * Registering a user device
      * Store reg id in users table
      */
      if (isset($_POST["name"]) && isset($_POST["email"]) && isset($_POST["regId"])) {
         $name = $_POST["name"];
         $email = $_POST["email"];
         $gcm_regid = $_POST["regId"]; // GCM Registration ID
         // Store user details in db
         include_once './functions.php';
         include_once './GCM.php';
         $db = new Functions();
         $gcm = new GCM();
         $res = $db->storeUser($name, $email, $gcm_regid);
         $registatoin_ids = array($gcm_regid);
         $message = array("product" => "shirt");
         $result = $gcm->send_notification($registatoin_ids, $message);
         echo $result;
         } else {
            echo " user details missing";
      }
   ?>

7. Create a send_pushnotification_message.php file. This file is used to send push notification to an Android device to send a request to the GCM server.
   
   send_pushnotification_message.php
   

   <?php
      if (isset($_GET["regId"]) && isset($_GET["message"])) {
         $regId = $_GET["regId"];
         $message = $_GET["message"];
         include_once './GCM.php';
         $gcm = new GCM();
         $registatoin_ids = array($regId);
         $message = array("price" => $message);
         $result = $gcm->send_notification($registatoin_ids, $message);
         echo $result;
      }
   ?>

8. Last and finally create a file called index.php and paste the following code into it. The following code will create a simple admin panel to list all the user devices and provides a panel to send push notification to individual devices.
   
   index.php
   

   <!DOCTYPE html>
   <html>
      <head>
         <title></title>
         <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
         <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js"></script>
         <script type="text/javascript">
            $(document).ready(function(){
            });
            function sendPushNotification(id){
            var data = $('form#'+id).serialize();
            $('form#'+id).unbind('submit');
            $.ajax({
               url: "send_pushnotification_message.php",
               type: 'POST',
               data: data,
               success: function(data, textStatus, xhr) {
                  $('.txt_message').val("");
               },
               error: function(xhr, textStatus, errorThrown) {
               }
            });
            return false;
         }
         </script>
      </head>
   <body>
   <?php
      include_once 'functions.php';
       $db = new Functions();
      $users = $db->getAllUsers();
      if ($users != false)
      $no_of_users = mysql_num_rows($users);
      else
         $no_of_users = 0;
      ?>
      <div class="container">
         <h1>No of Devices Registered: <?php echo $no_of_users; ?></h1>
         <hr/>
        <ul class="devices">
         <?php
            if ($no_of_users > 0) {
         ?>
         <?php
            while ($row = mysql_fetch_array($users)) {
         ?>
         <li>
         <form id="<?php echo $row["id"] ?>" name="" method="post" onsubmit="return sendPushNotification('<?php echo $row["id"] ?>')">
         <label>Name: </label> <span><?php echo $row["name"] ?></span>
         <div class="clear"></div>
         <label>Email:</label> <span><?php echo $row["email"] ?></span>
         <div class="clear"></div>
         <div class="send_container">
            <textarea rows="3" name="message" cols="25" class="txt_message" placeholder="Type message here"></textarea>
            <input type="hidden" name="regId" value="<?php echo $row["gcm_regid"] ?>"/>
            <input type="submit" class="send_btn" value="Send" onclick=""/>
         </div>
      </form>
      </li>
   <?php }
   } else { ?>
      <li>
         No Users Registered Yet!
      </li>
      <?php } ?>
      </ul>
      </div>
   </body>
   </html>