SetTimeout() not always working

stormcandi · June 20th, 2008, 01:20 PM

I am using the Set Timeout function to set my focus on a textbox in a modal popup when it is displayed. THe problem I am running into is that sometimes it is working and other times it does not work. I can'd figure out the reason why. It is set up on the client click of an image button. Can anyone assist me with having it work all the time? Below is my code.

Code:

function SetFocus(sender)
    {
        setTimeout("document.getElementById('<%= txtLName.ClientID %>').focus()", 1000); 
    }

Thanks in advance!

~Candi

Old Pedant · June 20th, 2008, 01:56 PM

I can think of a couple of reasons...

(1) Somehow, you aren't really getting the correct ID of the target. To check this, do a VIEW-->>SOURCE of the HTML.

(2) If it takes longer than one second for the modal dialog to completely load, then *of course* this will fail! There is no object there to set the focus *to*.

Number (2) is easy to fix:

function SetFocus( )
{
    var obj = document.getElementById('<%= txtLName.ClientID %>');
    if ( obj != null )
    {
        obj.focus( );
        return;
    }
    setTimeout("SetFocus()", 100);
}

You just keep waiting, 100 milliseconds at a time, until the object *DOES* exist.

stormcandi · June 20th, 2008, 02:47 PM

I tried what you posted, Old Pedant. I even tried a few variations of it, but it would not work at all. I started to get the error that focus can not be set if the control is invisible.....etc. I looked at the View Source, and the correct Client ID is being passed in.

~Candi

Old Pedant · June 20th, 2008, 03:10 PM

Ahhh...not what I thought..."the error that focus can not be set if the control is invisible..."

Interesting.

Maybe put the focus() call in a try...catch and retry if the error is caught??

Won't work on older browsers without try...catch, but you can't have everything.

Untested, but something like...

Code:

function SetFocus( )
{
    var obj = document.getElementById('<%= txtLName.ClientID %>');
    if ( obj != null )
    {
        try { 
            obj.focus( );
            return; // done if successful
        } catch (ignored) {
            /* just fall through */
        }
    }
    setTimeout("SetFocus()", 100);
}

I guess you don't really even need it that complex. Could probably simply do it as

Code:

function SetFocus( )
{
    try {
        document.getElementById('<%= txtLName.ClientID %>').focus();
        return;
    } catch (ignored) {
        /* just fall through */
    }
    setTimeout("SetFocus()", 100);
}

No?

stormcandi · June 20th, 2008, 03:24 PM

Old Pedant,

Although this time it did not break when executed, it also did not work. Again I tried some variations, but nothing. I also checked the Source to make sure it was the right ClientID still and it is the right onw.

~Candi

Old Pedant · June 20th, 2008, 03:26 PM

Sorry, then. Out of ideas.

It must be a timing issue, if it sometimes works and sometimes doesn't. But a timing of what I'll be darned if I know.

stormcandi · June 20th, 2008, 03:29 PM

Old Pedant,
Thanks for trying to help! Hopefully someone will see this and be able to help me so we can both have bigger brains. :D

~Candi

Old Pedant · June 20th, 2008, 03:29 PM

If you want to post real (minimal, please!) code, I'll try playing with it, but no guarantees, at all.

stormcandi · June 20th, 2008, 03:30 PM

I posted what I had. The function is called by the client click of an image button.

~Candi

Old Pedant · June 20th, 2008, 03:50 PM

Ummm...don't you *ALSO* cause the modal dialog to show??? That's the part I meant. What's the dialog look like? So we don't go create something entirely different. Just the HTML, mind you. Not the ASP.NET code.