- From: Ian Hickson <ian@hixie.ch>
- Date: Sun, 31 Oct 2004 18:55:05 +0000 (UTC)
- To: Doug Schepers <doug@schepers.cc>
- Cc: www-svg@w3.org
On Sun, 31 Oct 2004, Doug Schepers wrote: > | > | It would seem more logical for SVG to not have a special status here. > | SVG elements IMHO should be handled just like any other > | namespace's elements, and support XBL in the same way. Why > | are SVG elements more special than, say, XForms, XHTML, > | XSL:FO, or MathML elements? > > Assuming that SVG is the host language-- I'm not convinced the term "host language" is meaningful in an XBL context. > I think this restriction makes sense. I'd assume the same would apply > for any XBL host language. Styling of native elements should be left up > to CSS or other styling languages, not imposed by XBL. Styling native elements -- for example XForms, HTML form controls, etc -- is very much one of XBL's use cases. So I'm not sure I agree. > It occurs to me that were XBL binding allowed on native elements, we > could run into severe performance issues. For example, if an element > from the XForms NS were rendered in SVG (through an XBL binding) as a > 'rect', and the SVG 'rect' were bound to another shape through XBL (for > instance, 4 'line' elements), you would have a shadow tree off a shadow > tree. That seems problematic, and would leave us in a double-bind (as it > were). Multiple levels of bindings are already supported by XBL. Binding SVG elements would probably have very little effect on SVG itself. For example, binding a <rect>: <rect/> ...to a shadow tree: <xbl:template> <svg:circle/> </xbl:template> ...would have either no effect or cause the document to be in error, since the resulting flattened tree would be: <rect> <circle/> </rect> ...which is not valid SVG. > Can you describe a use case were you think this restriction would be > insurmountable? There are several (such as implementing a stylesheet that turns an SVG file into a description of the graphic for UAs that don't natively support SVG, such as non-graphical UAs) but my main reasoning is simply that SVG shouldn't be special-cased. It would be like XHTML saying "but by the way, you can't use XSLT with XHTML". > If I were dead-set on transforming SVG elements into other content, I > could simply create my own markup, in my own namespace, that duplicates > the SVG elements, and bind that with XBL. And then you would be taking a standard namespace, and inventing a proprietary namespace, and would thus lose any advantage to using SVG in the first place. -- Ian Hickson U+1047E )\._.,--....,'``. fL http://ln.hixie.ch/ U+263A /, _.. \ _\ ;`._ ,. Things that are impossible just take longer. `._.-(,_..'--(,_..'`-.;.'
Received on Sunday, 31 October 2004 18:55:08 UTC