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

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();
});