Solved

Does ajax call keeps an open connection to the server

Posted on 2016-09-21
2
86 Views
Last Modified: 2016-09-27
Hi,
I came across the following code on this site :
https://gist.github.com/jhbsk/4353139
// Long Polling (Recommened Technique - Creates An Open Connection To Server ∴ Fast)
(function poll(){
    $.ajax({ url: "server", success: function(data){
        //Update your dashboard gauge
        salesGauge.setValue(data.value);
    }, dataType: "json", complete: poll, timeout: 30000 });
})();

Open in new window


Although i dont see in documentation of ajax call that this will keep an open connection to the server.
And in one of the places where i did see this type of code being used the following was the content in network tab in chrome :
Screen-Shot-2016-09-21-at-5.50.42-PM.pngWhich means that indeed there is no time spent on Initial connection setup, SSL etc.
Please suggest what you think of this approach.

Thanks
0
Comment
Question by:Rohit Bajaj
2 Comments
 
LVL 9

Assisted Solution

by:Shahid Thaika
Shahid Thaika earned 150 total points
ID: 41808672
Normally AJAX does not keep a connection open. The code is a jQuery way of making an AJAX call. Once the call is made to the server and a response is received, then the code in the Success parameter is executed. If there is a failure, then the function in the Error parameter is executed, but that is not mentioned here.

Once both of those are done, the code / function against Complete is executed. The Complete parameter above is calling the Poll function, which in turn will make the AJAX call, and this will keep triggering the AJAX call to the server infinitely.

In terms of suggestions, personally I'd write a function for Complete which will call the Poll function using a timer (setTimeOut), so that you make fewer calls to the server. You also need an additional lines of code in Success to see if you are running the code ifor too long.
0
 
LVL 55

Accepted Solution

by:
Julian Hansen earned 350 total points
ID: 41808716
That is basically calling itself - on complete it calls poll and repeats.

This is a quick and dirty way of doing this. A better solution (one used by solutions like Firebase) - is to use web sockets and have changes pushed to the client by the server.
These articles may be of interest if you want to know more about web sockets
https://developer.mozilla.org/en-US/docs/Web/API/WebSockets_API/Writing_WebSocket_client_applications
https://developer.mozilla.org/en/docs/Web/API/WebSocket
https://developer.mozilla.org/en-US/docs/Web/API/WebSockets_API
1

Featured Post

Announcing the Most Valuable Experts of 2016

MVEs are more concerned with the satisfaction of those they help than with the considerable points they can earn. They are the types of people you feel privileged to call colleagues. Join us in honoring this amazing group of Experts.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
removing a class in javascript 4 50
Javascript 2 26
JQuery Search Filter 2 33
Mozilla Favorites 10 22
I found this questions asking how to do this in many different forums, so I will describe here how to implement a solution using PHP and AJAX. The logical flow for the problem should be: Write an event handler for the first drop down box to get …
International Data Corporation (IDC) prognosticates that before the current the year gets over disbursing on IT framework products to be sent in cloud environs will be $37.1B.
Google currently has a new report that is in beta and coming soon to Webmaster Tool accounts. This Micro Tutorial will highlight new features for Google Webmaster Tools.
This Micro Tutorial will demonstrate how nuggets on the Web are formatted by using Chrome Developer Tools. These tools would not only view the site's CSS but it can also modify it and save the CSS to use on your own site.

832 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question