Push Notifications for Web Browsers

83

How do you increase the site’s traffic? E-commerce businesses’ main goal is to keep engage their existed subscribers and get the new visitors. There are many ways to grow site’s traffic and customer engagement – by sending email notifications, SMS alerts, through social media and do web push notifications. Today, we are going to see how push notifications work for web browsers. These are the notifications that are sent to the users through desktop and mobile browsers. These notifications are delivered on a user’s desktop or mobile browser — regardless of whether or not the user is on the website. These notifications allow users to get timely updates from sites they love and allow developers to effectively re-engage them with relevant content to increase site’s traffic. Let’s start how this works.

This project is required following items

Website
Frontend website you have to include manifest.json file in the index.html

manifest.json
Basic metadata information about your website extension, this will help you to communicate with browser actions.

service-worker.js
This is a script file that your browser runs in the background and perform sync operations.

notification.js
A JavaScript file to allow browser notification. This has all the actions to send user registration token information to the backend server.

RESTful or ServerSide URL

Subscribe
Create a simple service side insert operation to store the user registration token.

Unsubscribe
Same way create a delete operation to delete the user registration token from the database.

Get Notification
This URL should return a notification data in JSON data format.

CURL Push Notification Application
A Server-side CURL project to send notifications to the subscribed users list.

Database
You have to create a database for storing user registration ids/tokens.

CREATE TABLE GMC{
gid INT PRIMARY KEY AUTO_INCREMENT,
rid TEXT
}
This will contain a push notification data.

CREATE TABLE notifications{
nid INT PRIMARY KEY AUTO_INCREMENT,
title VARCHAR(200),
msg VARCHAR(200),
logo VARCHAR(300),
name VARCHAR(100),
url VARCHAR(300)
}
 

Getting started with Firebase

Step 1
Create a Firebase project for Google Cloud Messing.

Step 2
Login to Google Developer Console and go to your Dashboard

Step 3
Agree firebase terms.

Step 3
Select your API project.

Step 4
Click select and choose your existing Firebase project.

Step 5
Choose existing project

Step 6
Copy your project authentication key for sending Google Cloud Messaing

Step 7
Your project client id.

manifest.json
Meta data information file to communicate with browsers. Here include your project client id, check Step 7 screenshot.

{

   “name”: “Web Push Demo”,
   “short_name”: “push_demo”,
   “version”: “1.0.0”,
   “description”: “A simple site with push notification”,
   “author”: {
   “name”: “Srinivas Tamada”
},
   “gcm_sender_id”: “Your_Client_ID”,
   “gcm_user_visible_only”: true

}

service-worker.js
JavaScript file that your browser runs at the background and perform sync operations. This will always communicate with your project api to get latest notification information. Upload this file in your project index location.

var self = this;

var urlMain;
self.addEventListener(“push”, function(event) {
   event.waitUntil(
      fetch(“https://yourwebiste.com/api/getNotification”, {
      method: “get”
   })
  .then(function(response) {
     return response.json();
   })
  .then(function(result) {

   urlMain = result.data.url;
   const options = {
      body: result.data.msg,
      icon: result.data.logo,
      image: result.data.name,
      action: result.data.url
    };
   self.registration.showNotification(result.data.title, options);
   })
   );
});
self.addEventListener(“notificationclick”, function(event) {
   event.notification.close();
   const promiseChain = clients.openWindow(urlMain);
    event.waitUntil(promiseChain);

});

index.html
Include manifest.json and notification.js file. Here notification.js is a controller and this works with service-worker.js.

<!DOCTYPE html>

<html>
<head>
<title>Push Demo</title>
<link rel=”manifest” href=”manifest.json”>
</head>
<body>
<div id=”container”>
<div class=”desc”> </div>
<button class=”pushButton” disabled>
   Subscribe
</button>
</div>
<script src=”notification.js”></script>
</body>

</html>

notification.js
JavaScript file to control all the subscribers’ information. Bit large file split into different parts.

DocumentContent Loader initilise the service worker and this will verify the user subscription. This Code will launch the Allow and Block popup.

var isPushEnabled = false;

var pushButton = document.querySelector(“.pushButton”);
var desc = document.querySelector(“.desc”);
var disableText = “Unsubscribe”;
var enableText = “Subscribe”;
var disableDesc = “Thank you message”;
var enableDesc = “Click <span class=’high’>Allow</span> button top left.”;
document.addEventListener(“DOMContentLoaded”, function() {
    if (isPushEnabled) {
      unsubscribe();
    } else {
      subscribe();
    }
    serviceWorkerCall();

});

serviceWorkerCall function will register the server-worker.js with initilise function for future actions.

function serviceWorkerCall() {

   if (“serviceWorker” in navigator) {
       navigator.serviceWorker.register(“/service-worker.js”)
       .then(initialiseState);
   } else {
        console.warn(“Service workers aren’t supported in this browser.”);
    }
}

function initialiseState() {
   if (!(“showNotification” in ServiceWorkerRegistration.prototype)) {
      console.log(“Notifications aren’t supported.”);
      return;
    }

    if (Notification.permission === “denied”) {
     console.log(“The user has blocked notifications.”);
     return;
    }

    if (!(“PushManager” in window)) {
     console.log(“Push messaging isn’t supported.”);
     return;
    }

    navigator.serviceWorker.ready.then(function(serviceWorkerRegistration) {
       serviceWorkerRegistration.pushManager
       .getSubscription()
       .then(function(subscription) {
           pushButton.disabled = false;
           if (!subscription) {
             return;
        }
        if (subscription) {
          sendSubscriptionToServer(subscription);
        }

     pushButton.textContent = disableText;
       desc.textContent = disableDesc;
       isPushEnabled = true;
      })
.catch(function(e) {
   console.log(“Error during getSubscription()”, e);
});
});

}

subscribe and unsubscribe function to change the message and button status.

function subscribe() {

   pushButton.disabled = true;
   navigator.serviceWorker.ready.then(function(serviceWorkerRegistration) {
   serviceWorkerRegistration.pushManager
   .subscribe({ userVisibleOnly: true })
   .then(function(subscription) {
      isPushEnabled = true;
      pushButton.textContent = disableText;
      desc.textContent = disableDesc;
      pushButton.disabled = false;
  if (subscription) {
     sendSubscriptionToServer(subscription);
  }
 })
.catch(function(e) {
  if (Notification.permission === “denied”) {
    console.warn(“Permission for Notification is denied”);
    pushButton.disabled = true;
  } else {
   console.error(“Unable to subscribe to push”, e);
   pushButton.disabled = true;
   pushButton.textContent = “Enable Push Messages”;
 }
 });
});
}
function unsubscribe() {
   pushButton.disabled = true;
   navigator.serviceWorker.ready.then(function(serviceWorkerRegistration) {
   serviceWorkerRegistration.pushManager
   .getSubscription()
   .then(function(pushSubscription) {
   if (!pushSubscription) {
     isPushEnabled = false;
     pushButton.disabled = false;
     pushButton.textContent = enableText;
     desc.textContent = enableDesc;
     return;
   }
   var temp = pushSubscription.endpoint.split(“/”);
   var registration_id = temp[temp.length – 1];
   deleteSubscriptionToServer(registration_id);
   pushSubscription.unsubscribe().then(function(successful) {
     pushButton.disabled = false;
     pushButton.textContent = enableText;
     desc.textContent = enableDesc;
     isPushEnabled = false;
  })
  .catch(function(e) {
    console.error(“Error thrown while unsbscribing from push messaging.”);
  });
 });
});

}

About functions are calling these following functions. Ajax calls to store and delete the user’s registation ids.

// send subscription id to server

function sendSubscriptionToServer(subscription) {
   var temp = subscription.endpoint.split(“/”);
   var registration_id = temp[temp.length – 1];
   fetch(
    “http://yourwebsite.com/api/insertGCM/” + registration_id,
    {
      method: “get”
     }
    ).then(function(response) {
     return response.json();
    });
}
function deleteSubscriptionToServer(rid) {
   fetch(“https://yourwebsite.com/api/deleteGCM/” + rid, {
    method: “get”
   }).then(function(response) {
   return response.json();
 });

}

InsertGCM
PHP code to insert registartion id in GCM table. Alwasy check HTTP_ORIGIN to avoid wrong inputs.

function insertGCM($rid) {

$check = false;
if($_SERVER[‘HTTP_ORIGIN’] && $_SERVER[‘HTTP_ORIGIN’] == “http://yourwesbite.com”){
$check = true;
}

if($check){
   $db = getDB();
   $sql1 = “SELECT * FROM GMC WHERE rid=:rid”;
   $stmt1 = $db->prepare($sql1);
   $stmt1->bindParam(“rid”, $rid,PDO::PARAM_STR);
   $stmt1->execute();
   $mainCount=$stmt1->rowCount();
   if($mainCount < 1){
      $sql = “INSERT INTO GMC(rid) VALUES (:rid)”;
      $stmt = $db->prepare($sql);
      $stmt->bindParam(“rid”, $rid,PDO::PARAM_STR);
      $stmt->execute();
      echo ‘{“success”:{“text”:”done”}}’;
   }
else{
  echo ‘{“success”:{“text”:”already users”}}’;
}
}
else{
   echo ‘{“error”:{“text”:”No access”}}’;
}

}

Delete
Delete GCM table data based on the registration id.

function deleteGCM($rid) {

$check = false;
if($_SERVER[‘HTTP_ORIGIN’] && $_SERVER[‘HTTP_ORIGIN’] ==”https://push.9lessons.info”){
  $check = true;
}

if($check){
   $db = getDB();
   $sql = “DELETE FROM GMC WHERE rid=:rid”;
   $stmt = $db->prepare($sql);
   $stmt->bindParam(“rid”, $rid,PDO::PARAM_STR);
   $stmt->execute();
   echo ‘{“success”:{“text”:”done”}}’;
}
else{
   echo ‘{“error”:{“text”:”No access”}}’;
}

}

GetNotification
Get latest notifiaction for service-worker.js

function getNotification(){

   $db = getDB();

   $sql1 = “SELECT title, msg, logo, url, name FROM notifications ORDER BYnid DESC LIMIT 1”;
   $stmt1 = $db->prepare($sql1);
   $stmt1->execute();
   $notification = $stmt1->fetch(PDO::FETCH_OBJ);
   $notification->action = $notification->url;
   $notification->click_action = $notification->url;
   if($notification){
     $notification = json_encode($notification);
     echo ‘{“data”: ‘ .$notification . ‘}’;
   }

}

Administrator for Sending Push Notifications

SendGCM.php
PHP Curl to communcate with Google Firebase APIs. Modify Your_Authorization_API and check Step 6.

<?php

function sendGCM($fields) {
  $url = ‘https://fcm.googleapis.com/fcm/send’;
  $fields = json_encode ($fields);
  $headers = array (
    ‘Authorization: key=’ . “Your_Authorization_Key”,
   ‘Content-Type: application/json’
  );
  $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_IPRESOLVE, CURL_IPRESOLVE_V4 );
  curl_setopt ( $ch, CURLOPT_POSTFIELDS, $fields );
  $result = curl_exec ( $ch );
  echo $result;
  curl_close ( $ch );
}

?>

Push Notification Form
Simple HTML form with title, message, logo and url inputs. Make sure give some authentication/login to protect this page.

<form autocomplete=”off” method=”post” action=””>

<div>
   <label>Title</label>
   <input type=”text” placeholder=”Title” name=”title”>
</div>
<div >
   <label>Message</label>
   <input type=”text” placeholder=”Message” name=”msg”>
</div>
<div >
   <label>Logo</label>
   <input type=”text” placeholder=”Logo” name=”logo” value=””>
</div>
<div >
   <label>Name</label>
   <input type=”text” placeholder=”Name” name=”name”>
</div>
<div >
   <label>URL</label>
   <input type=”text” placeholder=”URL” name=”url”>
</div>
<div >
   <input type=”submit” value=”Push Notification” name=”notificationSubmit”/>
</div>

</form>

home.php
This will insert form data and sending the push notications to registred users by calling $gcm->getIDs()

<?php

include(‘config.php’);
include(‘sendGMC.php’);
if(!empty($_POST[‘notificationSubmit’])){

   $title=$_POST[‘title’];
   $msg=$_POST[‘msg’];
   $logo=$_POST[‘logo’];
   $name=$_POST[‘name’];
   $url=$_POST[‘url’];
   if(strlen(trim($title))>1 && strlen(trim($msg))>1 &&strlen(trim($logo))>1 && strlen(trim($name))>1 && strlen(trim($url))>1 )
   {
     if($gcmClass->insertNotification($title, $msg, $logo, $name, $url)){
       $registrationId = $gcmClass->getIDs();
       $total_rids=[];
       foreach($registrationId as $r){
          array_push($total_rids, $r->rid);
       }

    $fields = array(‘registration_ids’  => $total_rids);
    sendGCM($fields);
    echo “Done”;
   }
  }
}
include(‘header.php’);

?>

gcmClass.php
PHP class for insert notification information and getting all the registration ids.

<?php

class gcmClass
{
   public function getIDs()
  {
   try{
     $db = getDB();
     $stmt = $db->prepare(“SELECT rid FROM GMC”);
     $stmt->execute();
     $data=$stmt->fetchALL(PDO::FETCH_OBJ);
     return $data;
   }
   catch(PDOException $e) {
   echo ‘{“error”:{“text”:’. $e->getMessage() .’}}’;
   }
 }
public function insertNotification($a, $b, $c, $d, $e)
{
  try{
   $db = getDB();
   $stmt = $db->prepare(“INSERT INTO notifications(title, msg, logo, name,url) VALUES(:title,:msg,:logo,:name,:url)”);
   $stmt->bindParam(“title”, $a,PDO::PARAM_STR) ;
   $stmt->bindParam(“msg”, $b,PDO::PARAM_STR) ;
   $stmt->bindParam(“logo”, $c,PDO::PARAM_STR) ;
   $stmt->bindParam(“name”, $d,PDO::PARAM_STR) ;
   $stmt->bindParam(“url”, $e,PDO::PARAM_STR) ;
   $stmt->execute();
   return true;
  }
  catch(PDOException $e) {
   echo ‘{“error”:{“text”:’. $e->getMessage() .’}}’;
   }

 }
}

?>

config.php
Database configuration file. You have to modify the database username and password.

<?php

/* DATABASE CONFIGURATION */
define(‘DB_SERVER’, ‘localhost’);
define(‘DB_USERNAME’, ‘username’);
define(‘DB_PASSWORD’, ‘password’);
define(‘DB_DATABASE’, ‘database’);
define(“BASE_URL”, “https://www.yourwebsite.com/”);
define(“SITE_KEY”, ‘yourSecretKeyyx’);

function getDB()
{
    $dbhost=DB_SERVER;
    $dbuser=DB_USERNAME;
    $dbpass=DB_PASSWORD;
    $dbname=DB_DATABASE;
    $dbConnection = new PDO(“mysql:host=$dbhost;dbname=$dbname”, $dbuser, $dbpass);
    $dbConnection->exec(“set names utf8”);
    $dbConnection->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    return $dbConnection;
}
    include(‘class/gcmClass.php’);
    $gcmClass = new gcmClass();
?>