I'm totally new to node.js and I want to implement push notification system on a MySql database. I have a notification table in my database. In this table I have store recipient_id that specify the recipient of the notification. Now I want when a new notification with recipient_id is equal to current logged in user's id notify that user. Something like Stackoverflow If you are in the for example java tagged questions, every time a new question with java tag create, a notification appear on top of the page : 1 question with new activity.
Sorry for my poor English. Please help me to implement this system, because I'm new to it.
I'm totally new to node.js and I want to implement push notification system on a MySql database. I have a notification table in my database. In this table I have store recipient_id that specify the recipient of the notification. Now I want when a new notification with recipient_id is equal to current logged in user's id notify that user. Something like Stackoverflow If you are in the for example java tagged questions, every time a new question with java tag create, a notification appear on top of the page : 1 question with new activity.
Sorry for my poor English. Please help me to implement this system, because I'm new to it.
- Did you implement it? – rns Commented May 19, 2016 at 9:39
2 Answers
Reset to default 9I have made a simple app like your requirement.
You can get help from following lines of code.You need to understand the basics of code. after that you will easily achieve your target. most of things from your requirement covered in this demo app.
Its not a exact but you will meet your target through this.
In this example a status post by any user will emit to all other users also at same time. we can manipulate it to achieve "1 new status".
make a table in database where your entries to be saved
CREATE TABLE status
(
`status_id` INT NOT NULL AUTO_INCREMENT,
`s_text` TEXT,
`t_status` TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
PRIMARY KEY ( `status_id` )
);
//server.js
var app = require("express")();
var mysql = require("mysql");
var http = require('http').Server(app);
var io = require("socket.io")(http);
/* Creating POOL MySQL connection.*/
var pool = mysql.createPool({
connectionLimit: 100,
host: 'localhost',
user: 'root',
password: '',
database: 'fbstatus',
debug: false
});
app.get("/", function(req, res) {
res.sendFile(__dirname + '/index.html');
});
io.on('connection', function(socket) {
console.log("A user is connected");
socket.on('status added', function(status) {
add_status(status, function(res) {
if (res) {
io.emit('new status', status);
} else {
io.emit('error');
}
});
});
});
var add_status = function(status, callback) {
pool.getConnection(function(err, connection) {
if (err) {
connection.release();
callback(false);
return;
}
connection.query("INSERT INTO `status` (`s_text`) VALUES ('" + status + "')", function(err, rows) {
connection.release();
if (!err) {
callback(true);
}
});
connection.on('error', function(err) {
callback(false);
return;
});
});
}
http.listen(3000, function() {
console.log("Listening on 3000");
});
//index.html
<html>
<head>
<title>Socket.io</title>
<script src="/socket.io/socket.io.js"></script>
<script src="https://ajax.googleapis./ajax/libs/jquery/2.1.3/jquery.min.js"></script>
<link rel="stylesheet" href="//maxcdn.bootstrapcdn./bootstrap/3.3.2/css/bootstrap.min.css">
<script src = "http://maxcdn.bootstrapcdn./bootstrap/3.3.2/js/bootstrap.min.js"></script>
<script>
$(document).ready(function(){
var socket = io();
$("#add_status").click(function(){
socket.emit('status added',$("#ment").val());
});
socket.on('new status',function(msg){
var count = $('#count_status').text();
var valCount = parseInt(count);
if(valCount>=1) {
valCount = valCount+1;
} else {
valCount = 1;
}
var showMsg = '<div id="count_status"> '+valCount+' </div> new status';
$("#show_ments").html(showMsg);
});
});
</script>
</head>
<body>
<div id="ment_box" style = "padding:5%;">
<textarea id="ment" rows="5" cols="70"></textarea><br /><br />
<input type="button" id="add_status" value="Add">
</div>
<div id= "show_ments" class = "jumbotron"></div>
</body>
</html>
Run the app with following mand node Server.js
Now run http://localhost:3000/ in browser and to see the result open a new window in which you post a status and see your new status notification in both the window.
Thanks
Edited: This a great startup tutorial. a few thing needs modification.
- connection.release() code ends up unreadable and not working. you should ets or remove it.
2.The actual output in my case:
You can do it 2 ways:
- Query the server every n seconds for any new messages. Pass a timestamp of the last time you checked as a parameter and if any notification since the last check, return as json and display them in the client. This is called a pull strategy.
- Or you can use
websocketswhich maintains a permanent connection between your client and server, and then you can send notifications to the client from your server code in real-time. Seesocket.iotutorials. This is called a push strategy.