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Is there a sleep/wait javascript function for firefox?

 
-1
 

I need to suspend processing in my script for a few seconds, and i am not sure how.

Thanks, sj

 
0
 

There is no "sleep" or "wait" operator in JavaScript. You can set a timer, though, and when the timer expires, it will execute a function.

setTimeout("alert('hello')",1250);

You could have it wait so many milliseconds, and then execute an empty procedure, I suppose.

 
1
 

What you usually do is what Tom has suggested, but you would invoke a call to the code that you want to execute after timeout.

So if you had an algorithm like such:

function myFunction(){
   doSomething();
   wait(500);
   doSomethingElse();
}

You would implement this with:

function myFunction(){
   doSomething();
   setTimeout(function(){doSomethingElse();}, 500);
}

This effective 'pauses' the execution of your code.

 
0
 

Just what i needed.

Thanks guys, sj

 
0
 

This solution is not really a sleep. It effectively postpones the execution of function called by the setTimeout method, but javasctipy is asynchronous, so the execution of the commands following the setTimeout method will happend immediately after.
After a couple of google queries I found the only solution to sleep was to execute this function:

function pause(millis) 
{
        var date = new Date();
        var curDate = null;

        do { curDate = new Date(); } 
        while(curDate-date < millis)
}

Problem with this approach is when you need a few of shor sleeps one after another. In this case the only thing that happends is the cpu usage is gonna hit the roof and the script gets paused till the last pause is executed.

 
0
 

Thanks nemo5 for your input! I needed a way to cause a method to stop in its tracks so the calling method didn't think the currentl one was done yet, and this should do it.

 
0
 

The two approaches (do while, and dosomething/settimeout(dosomeelse)) are used in different situations.
1. do while
You just want to pause, but are not expecting anything to happen in the browser while waiting (no document loading, no event). The javascript interpreter will be busy executing the while loop.
(Check http://www.sean.co.uk/a/webdesign/javascriptdelay.shtm)
2. dosomething/settimeout(dosomeelse)
If you want your code to wait for something to happen, like a dom node being created or loaded you have to resort to other tactics.
Joseph Moore at http://40withegg.com/2007/1/5/a-non-cpu-intensive-javascript-wait-loop calls it a non-cpu intensive wait. Meaning the browser can still function and thus perform job that your code is waiting on.

 
0
 

This code will freeze any threads after it's execution, so this is a useless one:

function jsWaitForDelay(delay) {
    var startTime = new Date();
    var endTime = null;
    do {
        endTime = new Date();
    } while ((endTime - startTime) < delay);
}

This codes will NOT freeze any threads after it's execution but only works for Firefox:

/**
 * Netscape compatible WaitForDelay function.
 * You can use it as an alternative to Thread.Sleep() in any major programming language
 * that support it while JavaScript it self doesn't have any built-in function to do such a thing.
 * parameters:
 *  (Number) delay in millisecond
*/
function nsWaitForDelay(delay) {
    /**
    * Just uncomment this code if you're building an extention for Firefox.
    * Since FF3, we'll have to ask for user permission to execute XPCOM objects.
    */
    netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");

    // Get the current thread.
    var thread = Components.classes["@mozilla.org/thread-manager;1"].getService(Components.interfaces.nsIThreadManager).currentThread;

    // Create an inner property to be used later as a notifier.
    this.delayed = true;

    /* Call JavaScript setTimeout function
     * to execute this.delayed = false
     * after it finish.
    */
    setTimeout("this.delayed = false;", delay);

    /**
     * Keep looping until this.delayed = false
    */
    while (this.delayed) {
        /**
         * This code will not freeze your browser as it's documented in here:
         * https://developer.mozilla.org/en/Code_snippets/Threads#Waiting_for_a_background_task_to_complete
        */
        thread.processNextEvent(true);
    }
}
 
0
 

I realize this is a pretty old thread, but it is easily found in Google.

Any approach that uses a while loop to wait is never going to be the best answer. We often refer to this technique as "spin wait" because it causes the cpu to keep crunching away at a process, sometimes stopping the entire machine (especially on older computers) meaning that your javascript wait could be intense enough for some users that their computing experience waits with you. This is not optimal.

While Javascript unfortunately does not provide a method of actually pausing the thread, setTimeout is your best bet. If there's any way that you can go to the trouble of implementing AlphaFoobar's method, then you 100% certainly should.

 
-1
 

Here is a website that has implemented a javascript sleep function in a few different ways. It also shows what methods are compatible with what browsers and operating systems.

http://www.devcheater.com

 
0
 

If you create C++ component with one single function which internaly calls Win32 Sleep() function, then you can use this function from your java script and suspend thread. This way you can even implement WaitForSingleObject, SetEvent functions and synchronize threads, hope this should work.

 
0
 

I have researched a lot about this, nobody has a solution that does not use up cpu and works across browsers...
Here is my copyrighted method that really works... only downside is you have to chop up your code.

<html>
<body>
<script>
//javascript sleep by "therealdeal"; copyrighted 2009
//global var
var i = 0;
function start()
{
    dothese(i);
    i++;
    sleep(); //runs a timer to run start() again
    //if i==whatever, can use some other timer loop, etc...
    //if i>whatever, ends...
}

function dothese(pi) { //pi=passed i
    //pieces of codes to run
    if (pi==0){alert('0');}
    if (pi==1){alert('1');}
    if (pi==2){alert('2');} 
    if (pi > 2){alert(pi);}
}

function sleep() {t=setTimeout("start()",1000);} //can be a lot more than this
function sleep2() {t=setTimeout("start()",2000);} //alternate timer

start();
</script>
</body>
</html>
 
0
 

Here's all you'd have to do:

Suppose you're waiting for an ID field to exist. In the initial place you want to do it, add the line:

setTimeout("recursiveWait()", 250);

Then define the function:

function recursiveWait()
{
      if (document.getElementById("waitingId") == null)
      {
             setTimeout("recursiveWait()", 250);
      }
      else
      {
             <Do what you were waiting for here.>
      }
}

The stack could get large and overflow if your timer is too small (e.g., 1 ms and it really takes 10 seconds), but with some tuning it should work.

 
0
 

I have researched a lot about this, nobody has a solution that does not use up cpu and works across browsers...
Here is my copyrighted method that really works... only downside is you have to chop up your code.

<html>
<body>
<script>
//javascript sleep by "therealdeal"; copyrighted 2009
//global var
var i = 0;
function start()
{
    dothese(i);
    i++;
    sleep(); //runs a timer to run start() again
    //if i==whatever, can use some other timer loop, etc...
    //if i>whatever, ends...
}

function dothese(pi) { //pi=passed i
    //pieces of codes to run
    if (pi==0){alert('0');}
    if (pi==1){alert('1');}
    if (pi==2){alert('2');} 
    if (pi > 2){alert(pi);}
}

function sleep() {t=setTimeout("start()",1000);} //can be a lot more than this
function sleep2() {t=setTimeout("start()",2000);} //alternate timer

start();
</script>
</body>
</html> 

end quote.

How is this copyrighted code? Variations of this code (if it works, I didn't check it) can be found in all applications that use Timeout and Interval.

 
0
 

Guys i need to do something similar to the above and i tried this

javascript:Code_1;wait(1000);Code_2;end();

Full code is the following

javascript:doc=document;if(window.frames.length>0)doc=window.main.document;url=document.URL;doc.forms[0].attack.click();wait(1000);doc=document;if(window.frames.length>0)doc=window.main.document;url=document.URL;doc.forms[0].submit.click();end();


But script executes the first part and then do nothing....
As error in console i get "wait is not defined"


Can someone correct this please?

 
0
 

Old thread... It's annoying to see old thread gets revived for nothing... Also, I usually use setTimeout() function to deal with sleep/wait anyway.

 
0
 

try this:
when the window loads do the following:
var count=0
var int=setInterval('count++',0001)
then, when you want to wait:
var currenttime=count;
var stop_now=(currenttime+[how long to wait, in milliseconds])
while(count<=stopnow){}
this may cause an temporarily infinite loop, but should be okay.

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