How to prevent “Stop running this Script” in browsers?

Question

I have an ASP.NET MVC page that has JQuery Editable Datatable that has 14 columns. I have a button (Apply No Findings)to do Client side calcultions snd apply for all Rows in tha

Answer 1

You can also consider HTML 5 workers

A web worker is a JavaScript running in the background, without affecting the performance of the page. When executing scripts in an HTML page, the page becomes unresponsive until the script is finished. A web worker is a JavaScript that runs in the background, independently of other scripts, without affecting the performance of the page.

Creating a new worker is simple. All you need to do is call the Worker() constructor, specifying the URI of a script to execute in the worker thread, set the worker's Worker.onmessage property to an appropriate event handler function.

var myWorker = new Worker("my_task.js");

myWorker.onmessage = function (oEvent) {
  console.log("Called back by the worker!\n");
};

Alternatively, you could use addEventListener() :

var myWorker = new Worker("my_task.js");

myWorker.addEventListener("message", function (oEvent) {
  console.log("Called back by the worker!\n");
}, false);

myWorker.postMessage(""); // start the worker.

You can see more details at: https://developer.mozilla.org/en-US/docs/Web/Guide/Performance/Using_web_workers

Answer 2

The problem is javascript is single-threaded, so if there is a function that takes too long to complete, this function could cause the UI not responding. Therefore, the browser will warn the user about long running script by displaying the message: "Stop running this script". The solutions to this problem are:

• Optimize your code so the function does not take so long.
• Use setTimeout to break the function execution into many pieces that are short enough.

Example code pattern:

var array = []; //assume that this is a very big array
var divideInto = 4;
var chunkSize = rowCount/divideInto;
var iteration = 0;

setTimeout(function doStuff(){
  var base = chunkSize * iteration;
  var To = Math.min(base+chunkSize,array.length);
  while (base < To ){
      //process array[base]
      base++;
  }
  iteration++;
  if (iteration < divideInto)
      setTimeout(doStuff,0); //schedule for next phase
},0);

The solution you take in your Example(2) is correct, but there is a problem in your code. That's the setTimeout does not run. Try changing your code like this:

RepeatingOperation = function(op, yieldEveryIteration) 
  {  
  var count = 0;  
  var instance = this;  
  this.step = function(args) 
    {    
       op(args); 
       if (++count <= yieldEveryIteration) 
       {          
         setTimeout(function() { instance.step(args); }, 1, [])         
       }    
    };   
  };

Modify your function ApplyNoFindings(), try this:

if (++i > iTotalRecords) 
 { 
    UpdateSummaryLine();
    UpdateSummaryLineReasonCode();
 }  

instead of:

if (++i < iTotalRecords) 
     { 
        ro.step(); 
     }  
     else 
     { 
        UpdateSummaryLine();
        UpdateSummaryLineReasonCode();
     }  

Note: not tested, just give you an idea how it should work

Answer 3

Despite another answer already accepted I want to place here general information for developers who will have this problem in feature:

By this link you can find information how to fix this from user side http://support.microsoft.com/kb/175500 - user can add one Registry key.

Also you can find there information about when this "Running slow" message appears:

By default, the key does not exist. If the key has not been added, the default threshold limit for the time-out dialog box is 5,000,000 statements for Internet Explorer 4 and later versions.

As you see slowness measured in javascript statements, not in time.