jQuery ajax call set timeout

Question

 $.ajax({
    url: "data.php"
}).done(function(data) { 
    //code
});

how to wrap this in jQuery timeout function for example send an ajax request every 2 sec.?

there is no jQuery timeout... you have javascript `setTimeout` like `setInterval(function(){...}, 2000)` — Arun P Johny, Sep 30 '13 at 13:10
Use `setInterval()` - although I'd question why you need to do this every 2 seconds? If you need that level of concurrency use websockets. — Rory McCrossan, Sep 30 '13 at 13:10
Look http://stackoverflow.com/questions/5687600/jquery-call-ajax-every-10-seconds — vborutenko, Sep 30 '13 at 13:11
You probably need to include some check to see if the previous call has completed before making a new one. — Johan, Sep 30 '13 at 13:12
Save the ajax call in a variable and look if `.readyState < 4`. If it's true, it hasn't been completed. — Johan, Sep 30 '13 at 13:16

score 4 · Accepted Answer · answered Sep 30 '13 at 13:11

4

If you wrap this in a setInterval, you run the risk of sending your server a ton of requests with the potential of not getting them all back in order. Put a timeout inside the callback:

function runAjax() {
    $.ajax({
        url: "data.php"
    }).done(function(data) { 
        //code
        setTimeout(runAjax, 2000); //Run it again in 2 sec
    });
}

runAjax(); //I suppose we should start the AJAX :D

answered Sep 30 '13 at 13:11

tymeJV

103,943
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maybe add runAjax() beneath to actually call the function once to get it starting :) – Alex Sep 30 '13 at 13:12
@Alex -- Probably a good idea :) – tymeJV Sep 30 '13 at 13:12
i want to refresh a particualr div when there is new content how can i do it – M1X Sep 30 '13 at 13:13
@rexhin -- Load the content into the new div in the `.done` – tymeJV Sep 30 '13 at 13:13
yes i know but how to refresh it when there is new content in data.php – M1X Sep 30 '13 at 13:14
@rexhin -- You have to replace the HTML of the targeted div with the response from `data.php` – tymeJV Sep 30 '13 at 13:15
You should use long polling instead: http://techoctave.com/c7/posts/60-simple-long-polling-example-with-javascript-and-jquery – Scalpweb Sep 30 '13 at 13:17

score 1 · Answer 2 · answered Sep 30 '13 at 13:12

1

I would do something like this:

var ajax = null;
function callAjax()
{
  if(ajax != null)
     ajax.abort();
  ajax = $.ajax({
    url: "data.php"
  }).done(function(data) { 
    //code
  });
  setTimeout(callAjax, 1000); // Every 1 second
}
callAjax();

This code will execute the Ajax call once every 1 second. If another request is running, it will kill it before running another one.

A better way would be to use long polling: http://techoctave.com/c7/posts/60-simple-long-polling-example-with-javascript-and-jquery

answered Sep 30 '13 at 13:12

Scalpweb

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14

id rather but the timeout call in the done callback – Alex Sep 30 '13 at 13:13
Depends on what you want to do. If you want to ensure the requests are sent every second or if you want to launch it again one second after it succeeds. It's actually much different. – Scalpweb Sep 30 '13 at 13:14
Why not `if(ajax && ajax.readyState < 4)` – Johan Sep 30 '13 at 13:17

score 0 · Answer 3 · answered Sep 30 '13 at 13:12

0

you can use setInterval.

var xhr;
setInterval(
   function runAjax() {
        if(xhr) {
            xhr.abort();
        }
        xhr = $.ajax({
            url: "data.php"
        }).done(function(data) { 

        });
    }, 2000
)

try like this.

answered Sep 30 '13 at 13:12

Anil kumar

4,107
1
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This is actually pretty bad: if the server starts to be slow, many requests will get queued. – Scalpweb Sep 30 '13 at 13:13
we can cancel the requests those are queued by using abort method of xhr. – Anil kumar Sep 30 '13 at 13:16
Yes, but it was not in the first version of your script, was it ? – Scalpweb Sep 30 '13 at 13:17

jQuery ajax call set timeout

3 Answers3