- From: Adam Barth <w3c@adambarth.com>
- Date: Wed, 22 Sep 2010 19:53:35 -0700
- To: "Leigh L. Klotz, Jr." <Leigh.Klotz@xerox.com>
- Cc: public-webapps@w3.org
Perhaps the new effort should be called XBL3? Adam On Wed, Sep 22, 2010 at 9:30 AM, Leigh L. Klotz, Jr. <Leigh.Klotz@xerox.com> wrote: > > > A version of this message was previously sent by W3C Team request to a > members-only list. > At Art Barstow's request, I am sending the message to public-webapps, with > all members-only content removed and all technical comments preserved. > I have also corrected one typo, where "XForms" was typed in place of "XBL". > > This message is in response to > http://lists.w3.org/Archives/Public/public-forms/2010Sep/0005.html > which reads in part > > Since XBL2 wasn't getting much traction, I've taken an axe to the spec > and > made a number of changes to the spec based on some discussions with some > browser vendors: > > ... > > The main changes are simplification: I've dropped namespace support, made > it part of HTML rather than its own language, dropped<style> > and<script> > in favour of HTML equivalents, dropped all the<handler> syntactic sugar > (and redirected event forwarding to internal object instead), dropped > <preload>, dropped mentions of XForms and XML Events, and so on. > > > As co-chair of the W3C Forms WG and representative to that group from > Xerox, I have been directed [W3C Forms WG Direction] to write the > following comments to HCG: > > XBL is a successful component technology which allows declarative markup > to be bound to implementations, and allows the implementations > themselves to recursively consist of declarative and eventually > imperative and user-agent-specific components. It thus provides for > declarative expressive power while still retaining the "unobtrusive" > aspects of separate implementation. > > One widely-deployed implementation of XBL is in Firefox. XBL in Firefox > is widely used, but is non-standard. XBL2 is an attempt to standardize > XBL. > > We applaud the desire of the HTML5 WG to incorporate aspects of XBL into > HTML5. Even if it is reduced from XBL and XBL2, having such facilities > in HTML5 will still help others using layered implementation technology > of which HTML5 is one part (viz. [Ubiquity XForms], [Web Backplane], > [XSLTForms]). > > One of the benefits of a W3C Recommendation is that the technology thus > developed can have uses beyond its initial crucible. > For example, at least two XForms implementations make use of XBL, and > a third shows that it can be used alongside. > In these cases, XBL is used to develop components and custom controls > for XHTML, some using XForms but some not. > > We applaud the desire of the HTML5 WG to incorporate aspects of XBL into > HTML, we ask that the HTML5 WG implement their own profile of XBL, and > the XBL2 Rec-track document not be changed to include the proposed > editor's changes removing XML namespaces, XML events, and other XML > features from the XBL2. > > Uses of XBL in XForms and XHTML+XForms: > > 1. The XForms Wikibook [XForms Wikibook Custom Controls] community > documentation shows a number of use cases for custom and aggregate > controls with XHTML+XForms, most of which center around the Firefox > implementation, but additional work is currently being done for other > implementations such as Orbeon. > > 2. Mozilla Firefox [Firefox Custom Controls] documents how to write > custom controls using Mozilla XBL. > Additionally, much of the Mozilla XForms XPI itself is implemented using > Mozilla's XBL. > Namespace and other support is already present in XBL in Firefox; > tetaining it in XBL2 would make it easier for such component > technologies to be implemented cross-browser. > > 3. Orbeon uses a profile of XBL2 [Orbeon] to create components in their > XHTML+XForms product. Their use case requires namespace support. They > have a few additions to XBL2, notably parameters. Orbeon has indicated > they have a number of concerns about some of the details of XBL2, and > that they are additionally not using all of it. However, the parts they > are using are the parts that the proposed editor's draft removes. > > 4. Xerox also uses a similar profile of XBL2 [Xerox], though somewhat > reduced in features from Orbeon's implementation. Xerox uses XBL2 as a > transformation step in an XProc-like pipeline to instantiate complex > controls in XHTML, both with and without XForms. Xerox uses the > parameter mechanism designed by Orbeon, but the implementation is different. > > > > In summary, please note that XBL technology has been in use as "glue" > inside browsers for implementing XForms, has been in use in such > browsers for components and extensions, and is also used for components > in XHTML and XHTML+XForms implementations that have no internal use of > XBL. Retaining XBL2 as a Rec-track document is important for the Forms > WG, because it can be used along with XForms, just as can XSLT and > XProc, to great advantage. Incorporating aspects of XBL into HTML5 is > laudable, and we do not wish to hinder it, though we do point out that > XML Event support is merely syntax for DOM Events, and that Namespace > support is already present for XBL in browsers, so it would not seem > that removing either is motivated by practical concerns. > > > > References: > [W3C Forms WG Direction] > http://lists.w3.org/Archives/Public/public-forms/2010Sep/att-0026/2010-09-15.html#topic11 > [Firefox Custom Controls Examples] > https://developer.mozilla.org/en/XForms/Custom_Controls_Examples > https://developer.mozilla.org/en/XForms/Custom_Controls > [Orbeon] > http://wiki.orbeon.com/forms/doc/developer-guide/xbl-components-guide > No browser support is required. > [Xerox] > At present, this is work in development for product release, but works > with XSLT, XProc, and the AgenceXML XSLTForms XForms processor. > No browser support is required. > [XForms Wikibook Custom Controls] > http://en.wikibooks.org/wiki/XForms/Custom_Controls > [XSLTForms] > http://www.agencexml.com > [Ubiquity XForms] > http://code.google.com/p/ubiquity-xforms/ > [Web Backplane] > http://webbackplane.com/ > > Leigh L. Klotz, Jr. > Co-Chair W3C Forms Working Group > Xerox Corp. > > >
Received on Thursday, 23 September 2010 03:50:24 UTC