Real-time Notifications with javascript [closed]

Question

Real-time Notifications with javascript [closed]

Navigation

#1 by (2 votes)

1

I'm building a Java application that should show on-screen notifications in real time.

A teacher requests a reservation;

Reservation data is stored in a json object (or in a request table);

At the same time, a notification is displayed on the operator's screen;

The operator can approve the reservation, which would give a INSERT in the bank with the reservation data.

I figured the json form would be easier, so it would not involve Java or SQL in the process. But my question: is it how to do it exactly? I do not know much about JavaScript yet, but I imagine it would be necessary to use ajax, correct? Could you help me with this?

javascript jquery json node.js

asked by anonymous 09.02.2017 / 18:59

1 answer

Adding C # DataTable columns with Linq Windows form integration with html page

score 2 · Answer 1

You have two options mostly.

One is to call polling via ajax, that is, in the operator's client a request is sent every x time interval to check if there is a new reservation. This is a simple way to verify the information but many unnecessary server requests are sent. Here's an example that makes a call every 5 seconds:

(function poll() {
setTimeout(function() {
    $.ajax({
        url: "/server/api/function",
        type: "GET",
        success: function(data) {
            console.log("polling");
        },
        dataType: "json",
        complete: poll,
        timeout: 2000
    })
}, 5000);

}) ();

The other solution is to use websockets through the Socket.io API to maintain an open connection between the client and the server without having to make useless queries . This is an old article but you can help Connecting to Socket.io

Even if you do not know a lot about javascript it is worth exploring the second option that is more current and advanced.