using a function that requires parameters with setTimeout

@Karen_NelsonMar 17.2006

Hi everybody,
I am trying to write some functions involving setTimeout, but I’m getting hung up on passing parameters to the function referenced by setTimeout. For example, I have a function RotatePictures that takes 3 parameters — a number, a string, and an array. The first two work fine (well, there might be an easier way to get them too, if anyone knows) but the array results in an error (the name is not recognized, has no properties):

[CODE]function rotatePictures(wait, billbd, picts) { pictNum = pictNum+1; if (pictNum==picts.length) pictNum=0; document.getElementById(billbd).src = picts[pictNum].name; setTimeout(‘rotateBoard(‘+wait+’, “‘+billbd+'”, picts)’, wait); }[/CODE]

At one point I tried to make a custom object with rotatePictures as a method, so that the call to setTimeout was

setTimeout(‘this.rotatePictures();’);

However, I got an error that this.rotatePictures was not recognized.

I am guessing that the reason for these errors is that when the thread calls rotatePictures, it is out of the scope of ‘this’ or picts, but I don’t know what to do about it.

thanks for your help! Karen.

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10 Comments(s) _↴

@mrhooMar 17.2006 — #Make up your string first, then call setTimeout:

[CODE]function rotatePictures(wait, billbd, picts) {
 pictNum = pictNum+1; 
 if (pictNum==picts.length) pictNum=0;
 document.getElementById(billbd).src = picts[pictNum].name;
 var str='rotateBoard('+wait+', "'+billbd+'", picts)';
 setTimeout(str, wait);
 }
 [/CODE]

if it doesn't work:

look at the string to see why.

setTimeout works just like eval, but eval gives you better errors:

try eval(str) just for debugging if it gets mean.

Or pass the code without the timeout and make sure that works

@James_GatkaMar 17.2006 — #Create the image array like this:

[CODE]<html>
 <head>
 <script type="text/javascript">
 
  var imgArray = [];
  imgArray['picts'] = ["one.jpg","two.jpg","three.jpg"];
 
  function rotateBoard(nPix){
 
   alert(nPix);
  }
 
  function rotatePictures(){
 
   setTimeout("rotateBoard(imgArray['picts'])", 1000);
  }
 
 </script>
 </head>
 <body>
 
 <input type="button" value="Test" onclick="rotatePictures()">
 
 
 </body>
 </html>[/CODE]

@griff777Mar 17.2006 — #Hi everybody,

I am trying to write some functions involving setTimeout, but I'm getting hung up on passing parameters to the function referenced by setTimeout. For example, I have a function RotatePictures that takes 3 parameters -- a number, a string, and an array. The first two work fine (well, there might be an easier way to get them too, if anyone knows) but the array results in an error (the name is not recognized, has no properties):

[CODE]function rotatePictures(wait, billbd, picts) {
 pictNum = pictNum+1; if (pictNum==picts.length) pictNum=0;
 document.getElementById(billbd).src = picts[pictNum].name;
 setTimeout('rotateBoard('+wait+', "'+billbd+'", picts)', wait);
 }[/CODE]

At one point I tried to make a custom object with rotatePictures as a method, so that the call to setTimeout was

setTimeout('this.rotatePictures();');

However, I got an error that this.rotatePictures was not recognized.

I am guessing that the reason for these errors is that when the thread calls rotatePictures, it is out of the scope of 'this' or picts, but I don't know what to do about it.

thanks for your help! Karen.[/QUOTE]

I noticed, the "function" name is "rotatePictures", but the setTimeout call is to "rotateBoard".

I am not sure, but usually the "setTimeout" points back or "recursively" to the same function that originally set it.

Thus, a timer'd function that is always in the loop.

Not sure that helps...

@Karen_NelsonauthorMar 22.2006 — #Thanks everybody for your advice. In the end I did get it to work by messing around with various permutations of quotation marks, and fixing the mixup between rotateBoard and rotatePictures. The suggestion to use eval is a good one!

-Karen.

@phpnoviceMar 22.2006 — #This:

<i>
 </i>setTimeout('rotateBoard('+wait+', "'+billbd+'", picts)', wait);

is more simply coded as follows (no slashes required):

<i>
 </i>setTimeout('rotateBoard('+wait+', "'+billbd+'", picts)', wait);

As for passing an array in setTimeout as an argument, in your case you can code that this way:

<i>
 </i>setTimeout('rotateBoard('+wait+', "'+billbd+'", ["'+pics.join('","')+'"])', wait);

@gphMar 22.2006 — #To add, you can pass objects like this

<i>
 </i>setTimeout(function(){rotateBoard(wait,billbd,picts)},wait);

@phpnoviceMar 22.2006 — #To add, you can pass objects like this

<i>
 </i>setTimeout(function(){rotateBoard(wait,billbd,picts)},wait);

[/QUOTE]
Just curious, but have you actually used that method successfully? I ask, because, just looking at it, it seems like it could not work -- i.e., scope being an issue. I could try it myself, but I though I'd just ask you. ?

@gphMar 22.2006 — #Yes I use it alot, it's a lazy persons approach to setTimeout ?

<i>
 </i>function foo(){
 var a=[window.foo];
 setTimeout(function(){alert(a[0])},100);
 }
 foo()

@shrageApr 06.2006 — #i have designed a person object which has functions

this.GetFullName = function()

{

return this.FirstName + " " + this.LastName;

}

now i want to call the GetFullName() function of this instance using the window.setTimeOut function

this.AlertFullName = function(wait)

{

window.setTimeOut(function(){alert(this.GetFullName())},wait);

}

But it dosen't work, how do i go about it?

@gphApr 06.2006 — #setTime[COLOR=Red]o[/COLOR]ut

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