Re: XForms schema: mustUnderstand and extension

Hi Jan,

> Does anyone disagree that extension
> should be permitted as a child of *any* XForms element? What about as a
> child of elements (i.e. setvalue) whose content models currently do not
> permit other elements as children? Are multiple extension elements permitted
> as a child of the same XForms element? Can the extension element appear
> anywhere in the sequence of child elements?

It would be interesting to see how people have implemented
xf:extension, in order to see what the options are.

What we've done in formsPlayer is to treat xf:extension just like an
xf:instance that was 'local' to the parent element. At run-time we
parse the contents of the xf:extension, and then create an attribute
called 'extension' on the parent node, which contains a DOM with the
contents of the xf:extension.

This is then available to any script, in particular to our XBL
widgets, which makes it a very convenient way for an author to provide
extra data for run-time use.

Taking this approach does mean for us though, that it would be more
logical if only one xf:extension was allowed per element. But given
that xf:extension wasn't defined very clearly in the first place, I'm
not at all saying that our approach is supported by the spec--simply
that this is the approach we took, to try to make something useful
from xf:extension.

I'd be interested to hear how others have made use of xf:extension.

Regards,

Mark

-- 
Mark Birbeck
CEO
x-port.net Ltd.

e: Mark.Birbeck@x-port.net
t: +44 (0) 20 7689 9232
w: http://www.formsPlayer.com/
b: http://internet-apps.blogspot.com/

Download our XForms processor from
http://www.formsPlayer.com/

Received on Thursday, 24 August 2006 12:12:58 UTC