如何停止运行此setTimeout函数？

Question

I use the function below to check on the status of a JSON file. It runs every 8 seconds (using setTimeout) to check if the file has changed. Once the JSON's status becomes 'success' I no longer want to keep calling the function. Can someone please show me how to do this? I suspect it involves the use of clearTimeout, but I'm unsure how to implement this.

Cheers!

  $(function() {
    var checkBookStatus = function() {
       var job_id = "#{@job.job_id}";
       var msg = $('.msg');
       var msgBuilding = $('#msg-building');
       var msgQueuing = $('#msg-in-queue');
       var msgSuccessful = $('#msg-successful-build');
       var msgError = $('#msg-error'); 
       $.ajax({ 
         url: '/jobs/'+job_id+'/status.json',

           datatype: 'JSON',
           success:function(data){
             if (data.status == "failure")  {
               msg.hide();          
               msgError.show();
             }
             else if (data.status == "#{Job.queue}")  {
            msg.hide();          
            msgQueuing.show();
         }
             else if (data.status == "#{Job.building}")  {
            msg.hide();          
            msgBuilding.show();
         }             
         else if (data.status == "#{Job.failure}")  {
             msg.hide();          
             msgError.show();
         }
         else if (data.status == "#{Job.success}")  {
             msg.hide();          
             msgSuccessful.show();

              }                    
           },       
       }).always(function () {
            setTimeout(checkBookStatus, 8000);
      });
    };    
   checkBookStatus();    
  });

Answer 1

t = setTimeout(checkBookStatus, 8000); when you decide to stop the timeout use this clearTimeout(t); .

Answer 2

use clearTimeout

eg you defined :

id = setTimeout(checkBookStatus, 8000);  

then you can remove this function by :

clearTimeout(id)

Answer 3

Call clearTimeout with the value previously returned by setTimeout . This would give you something like:

$(function() {
  var timeoutID;
  var checkBookStatus = function () {
      […]
      else if (data.status == "#{Job.success}")  {
          clearTimeout(timeoutID);
      […]
       }).always(function () {
        timeoutID = setTimeout(checkBookStatus, 8000);
      […]

Answer 4

When you use setTimeout , use like this:

var myTime = setTimeout(checkBookStatus, 8000);

to clear it just:

clearTimeout(myTime);

Answer 5

Before your call of checkBookStatus() at the end, put another call: var interval = setInterval(checkBookStatus, 8000); . Then on success you can clearInterval(interval) .

Do not use setTimeout for iteration.

A lot of answers are suggesting just to use clearTimeout() however, you are checking the status after the timeout has expired, there is no timeout to clear. You need to not call setTimeout() in your always() function rather than to clear anything. So you could re-inspect the status inside your always() function I suppose, but your data object isn't in scope there. It would be preferable to just use setInterval() outside of your checkBookStatus() function.

$(function() {
    var checkBookStatus = function() {
        var job_id = "#{@job.job_id}";
        var msg = $('.msg');
        var msgBuilding = $('#msg-building');
        var msgQueuing = $('#msg-in-queue');
        var msgSuccessful = $('#msg-successful-build');
        var msgError = $('#msg-error'); 
        $.ajax({ 
            url: '/jobs/'+job_id+'/status.json',
            datatype: 'JSON',
            success:function(data){
                if (data.status == "failure")  {
                    msg.hide();          
                    msgError.show();
                }
                else if (data.status == "#{Job.queue}")  {
                    msg.hide();          
                    msgQueuing.show();
                }
                else if (data.status == "#{Job.building}")  {
                    msg.hide();          
                    msgBuilding.show();
                }             
                else if (data.status == "#{Job.failure}")  {
                    msg.hide();          
                    msgError.show();
                }
                else if (data.status == "#{Job.success}")  {
                    msg.hide();          
                    msgSuccessful.show();
                    clearInterval(interval);
                }                    
            }       
        });
    };    
    var interval = setInterval(checkBookStatus, 8000);    
    checkBookStatus();
});

Answer 6

the following should work...

the setTimeout function return an instance of the setTimeout function. Keep this value in a variable and pass it to the function clearTimeout when you want to prevent the event from firing again.

ie

    var t = setTimeout(1000, someFunction);
...

//after you no longer need the timeout to fire, call

clearTimeout(t);