W3C home > Mailing lists > Public > www-svg@w3.org > January 2005

SVG12: Locating animation targets

From: Bjoern Hoehrmann <derhoermi@gmx.net>
Date: Thu, 13 Jan 2005 16:27:49 +0100
To: www-svg@w3.org
Message-ID: <41ef6e30.66895812@smtp.bjoern.hoehrmann.de>

Dear Scalable Vector Graphics Working Group,

  Considering the following fragment,

  ...
  <xbl:xbl>
    <xbl:definition element="my:a">
    <xbl:template>
      <animate ... />
    </xbl:template>
    </xbl:definition>
  </xbl:xbl>
  ...
  <my:div>
    <my:p xml:id='a'>...</my:p>
    <my:p>...</my:p>
    <my:p>...</my:p>
    <my:p>...<my:a xlink:href='#a'>...</my:a>...</my:p>
  </my:div>
  ...

according to section 3.6 of SVG 1.2 the animate element's target is the
first my:p element. If the xlink:href attribute is removed, the target
would be the last my:p element. This does not seem to make much sense,
it seems that the xlink:href attribute is abused here and one needs to
change the semantics of the custom fragment to change the behavior, e.g.
by using a different value for xlink:href or by removing the attribute
alltogether.

It further seems that implementations are not required to expose the
animated value of attributes on custom elements, which means one cannot
write script code that considers new animated values which means that
animating attributes on custom elements would have little effect in
practise.

It finally seems impossible to e.g. bind my:p to a svg:rect element and
let that element be target of the svg:animate element in the example
above unless the animation gets an id which is then referenced from the
xlink:href attribute; this would however create duplicate IDs if there
are multiple my:a elements which is not exactly desirable.

Thus, please change the Working Draft such that xlink:href attributes on
custom elements have no effect on SVG/sXBL processing. There should be
better means to achieve the desired effects here like new attributes in
a specific namespace to reference elements in the bound document or by
locating the target of an animation via XBL traversal.

regards.
-- 
Björn Höhrmann · mailto:bjoern@hoehrmann.de · http://bjoern.hoehrmann.de
Weinh. Str. 22 · Telefon: +49(0)621/4309674 · http://www.bjoernsworld.de
68309 Mannheim · PGP Pub. KeyID: 0xA4357E78 · http://www.websitedev.de/ 
Received on Thursday, 13 January 2005 18:31:13 GMT

This archive was generated by hypermail 2.3.1 : Friday, 8 March 2013 15:54:29 GMT