如何停止运行此setTimeout函数？ [英] How can I stop this setTimeout function from running?

问题描述

我使用下面的函数检查JSON文件的状态。它每8秒运行一次（使用setTimeout）来检查文件是否已更改。一旦JSON的状态变为成功，我就不再想继续调用该函数了。有人可以告诉我该怎么做吗？我怀疑它涉及使用clearTimeout，但我不确定如何实现它。

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.

干杯！

  $(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();    
  });

推荐答案

在您调用 checkBookStatus之前（）最后，再拨一个电话： var interval = setInterval（checkBookStatus，8000）; 。然后在成功时你可以 clearInterval（interval）。

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

不要使用 setTimeout 进行迭代。

很多答案建议只使用 clearTimeout（）但是，您在超时过期后检查状态，没有超时要清除。您不需要在 always（）函数中调用 setTimeout（）而不是清除任何内容。所以你可以重新检查我想的 always（）函数内的状态，但你的数据对象不是在那范围内。最好只使用 checkBookStatus（）函数的 setInterval（） 。

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();
});

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