W3C home > Mailing lists > Public > www-svg@w3.org > December 2004

RE: sXBL implementations

From: Mark Birbeck <mark.birbeck@x-port.net>
Date: Wed, 8 Dec 2004 20:13:43 -0000
To: "'Elliotte Harold'" <elharo@metalab.unc.edu>
Cc: <www-svg@w3.org>
Message-ID: <005601c4dd62$6d47c4d0$6701a8c0@W100>


We use 'the XBL family' in formsPlayer, which is an XForms processor that
plugs into IE6. The current public releases -- versions 1.x -- use it for
messages and a few bits and bobs (the multimodal demonstration on our
web-site has text-to-speech messages, and this functionality has all been
added using XBL).

Version 2 of formsPlayer uses XBL for just about everything, from defining
all our UI widgets (not just messages), allowing form authors to define
custom controls, specifying new XForms submission techniques, and other

XBL has generally attracted attention for its ability to allow you to define
custom controls with other languages, such as SVG, SSML or VoiceXML. But I
feel it also has an important role to play in making other extensions easy
to specify, such as submission processes, extra validation modules, XPath
extension functions, and so on.

Of course, you've no doubt spotted that I keep using the term 'XBL' rather
than 'sXBL', so maybe I haven't answered your question. But that is because
there are features that we needed from the 'old' XBL spec that aren't in
sXBL as it stands. Rather than implement a non-standard sXBL -- and get shot
down! -- we decided it was safer for now to implement most of Mozilla's XBL
1.0. It will be very easy for us to change when the time is right. (Just in
passing, the kinds of features we needed were the ability to create
properties and methods on the XBL object, as well as being able to map a
property on the XBL object to a property in an underlying SVG control.)

One final point, our 'XBL Engine' is a COM object, and we have a feature
whereby a new COM object can be created using an XBL file to build it. This
makes the whole thing independent of a browser, which I feel gives XBL a
very bright future as a cross-platform tool. There are many times where you
need to create an object for your application and you don't need a 'heavy'
language like C++, especially if performance is not an issue; in my view XBL
becomes a very neat way of defining these objects.

And with our component IE6 continues to make a reasonable showing in the
standards war ;)

I don't know if that answers your question Elliotte, but I hope it convinces
you at least, that (s)XBL has a lot of potential, and is a key technology in
the web application space.



Mark Birbeck
x-port.net Ltd.

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

Download our XForms processor from

> -----Original Message-----
> From: www-svg-request@w3.org [mailto:www-svg-request@w3.org] 
> On Behalf Of Elliotte Harold
> Sent: 07 December 2004 22:23
> To: Robin Berjon
> Cc: www-svg@w3.org
> Subject: Re: sXBL implementations
> Robin Berjon wrote:
> > Do you mean "known" as in by people on the WG, or a more 
> general one? 
> > :)
> > More seriously, last I hear Cameron was working 
> implementing sXBL on 
> > Batik, and yes the WG's heard of implementations being 
> worked on but I 
> > don't know how public they are at this point.
> > 
> Well ideally, I'd like to hear of a completely conformant, 
> open source 
> implementation that's fully debugged and well documented, 
> and, oh yeah, 
> throw in world peace while you're at it. :-) Practically, I am 
> interested in knowing how far along this stuff is, and where. Any 
> information is useful.
> -- 
> Elliotte Rusty Harold  elharo@metalab.unc.edu
> XML in a Nutshell 3rd Edition Just Published! 
> http://www.cafeconleche.org/books/xian3/
> http://www.amazon.com/exec/obidos/ISBN=0596007647/cafeaulaitA/
Received on Wednesday, 8 December 2004 20:14:01 UTC

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