xxforms:repeat-current problems

Hi All,

I'm running into a serious problem with slowness in loading a large XForms page. I currently working with a fairly complicated order form comprising of 1860 lines of XForms source.  The forms appears to take a long time to load, but in fact it's the Javascript initialization that's taking a long time.

By enabling the debug messages in xforms.js, I figured out that it's taking 5.5 seconds to run the function xformsInitializeControlsUnder() on a dual-core 3.0 Ghz machine!  This is really not acceptable because in Firefox you get a warning message saying that the Javascript is taking too long to run and asks if you want to stop the Javascript.  (Although this timeout value is changable in Firefox, we don't want to tell users to have to change that!)  In IE although there's no warning message, but the page is unresponsive for the time it takes to do the Javascript initialization, which really makes the system feel really slow.

Good news is ... I've tracked down the majority of the slowness to the call to the function xformsUpdateStyle() which is the last thing that
xformsInitializeControlsUnder() does in its element initialization loop.  By simply commenting out xformsUpdateStyle(), I get the initialization time to
under 1.5 seconds, that's almost 75% reduction. Yet the form still seems to work properly with that line commented out.  So my question is, what is xformsUpdateStyle() doing and it is doing anything essential?  could I live without it?  Or could the function be optimized somehow?  Seems rather strange that 75% of the initialization time is spent on initializing style.  Of course I'm not know if any essential functionality is involved in xformsUpdateStyle().

I am considering breaking up the form into multiple pages, but I'd rather not if I can get the performance to be acceptable (1.5 seconds load would be acceptable as opposed to 5.5 seconds) since breaking up the form introduces a lot of complexity in merging parts of the XML together, not to mention that I have many controls whose behavior depend on the state of controls in the form.  Even though the form has a lot in it, it does not appear overly complex to the user because I make use of tab controls and collapsible group boxes.

Thanks in advance for your help.

Larry T. Chen
Software Engineer
Intelenet Communications, Inc.

--
You receive this message as a subscriber of the [hidden email] mailing list.
To unsubscribe: [hidden email]
For general help: [hidden email]
ObjectWeb mailing lists service home page: http://www.objectweb.org/wws
  

Hi All,

I've tracked down the slowness even further.  It appears that the call to function hasClass() in the YAHOO dom.js has a lot to do with it.  It's using a regular expression to test if the class name exists for a given element!  What overkill!  I replaced the body of the hasClass() function with a quick test

return !el || !el.hasAttribute('class') ? false : String(el.getAttribute('class')).indexOf(className,0) >= 0;

and that gets the initialization time for my complex order form down to 3.0 seconds (down from 5.5 seconds)  all because of one function!  This function gets called a lot in xformsUpdateStyle(), hence the dramatic improvement.   3.0 seconds is still a little slow ... any help on further optimization would be greatly appreciated.

Larry T. Chen
Software Engineer
Intelenet Communications, Inc.


Larry T. Chen wrote:

Hi All,

I'm running into a serious problem with slowness in loading a large XForms page. I currently working with a fairly complicated order form comprising of 1860 lines of XForms source.  The forms appears to take a long time to load, but in fact it's the Javascript initialization that's taking a long time.

By enabling the debug messages in xforms.js, I figured out that it's taking 5.5 seconds to run the function xformsInitializeControlsUnder() on a dual-core 3.0 Ghz machine!  This is really not acceptable because in Firefox you get a warning message saying that the Javascript is taking too long to run and asks if you want to stop the Javascript.  (Although this timeout value is changable in Firefox, we don't want to tell users to have to change that!)  In IE although there's no warning message, but the page is unresponsive for the time it takes to do the Javascript initialization, which really makes the system feel really slow.

Good news is ... I've tracked down the majority of the slowness to the call to the function xformsUpdateStyle() which is the last thing that
xformsInitializeControlsUnder() does in its element initialization loop.  By simply commenting out xformsUpdateStyle(), I get the initialization time to
under 1.5 seconds, that's almost 75% reduction. Yet the form still seems to work properly with that line commented out.  So my question is, what is xformsUpdateStyle() doing and it is doing anything essential?  could I live without it?  Or could the function be optimized somehow?  Seems rather strange that 75% of the initialization time is spent on initializing style.  Of course I'm not know if any essential functionality is involved in xformsUpdateStyle().

I am considering breaking up the form into multiple pages, but I'd rather not if I can get the performance to be acceptable (1.5 seconds load would be acceptable as opposed to 5.5 seconds) since breaking up the form introduces a lot of complexity in merging parts of the XML together, not to mention that I have many controls whose behavior depend on the state of controls in the form.  Even though the form has a lot in it, it does not appear overly complex to the user because I make use of tab controls and collapsible group boxes.

Thanks in advance for your help.

Larry T. Chen
Software Engineer
Intelenet Communications, Inc.

--
You receive this message as a subscriber of the [hidden email] mailing list.
To unsubscribe: [hidden email]
For general help: [hidden email]
ObjectWeb mailing lists service home page: http://www.objectweb.org/wws
  

--
You receive this message as a subscriber of the [hidden email] mailing list.
To unsubscribe: [hidden email]
For general help: [hidden email]
ObjectWeb mailing lists service home page: http://www.objectweb.org/wws