Linking Contention: xlink:show vs. target

In looking at http://www.w3.org/Graphics/SVG/Test/20061213/htmlEmbedHarness/full-linking-a-07-t.html
it states that:

  "The bottom-most (blue) arrows links to the same external SVG file,
but with xlink:show="replace". Both the left and the right blue arrows
should produce the image of the linkingToc-t.svg in a new frame."

I believe this is an error in the test case as a result of the
confusing spec.  The SVG fragment in question is:

  <a xlink:href="../images/linkingToc-t.svg" xlink:show="replace" target="foo">
    <path fill="aqua" stroke="red" d="M 165,40 h 100 v -12 l 45 36 l
-45 36 v -12 h -100 z"/>
  </a>

The issue results because we have xlink:show="replace" in the same
link as target="foo" (which is an invalid frame name).

xlink:show says (http://www.w3.org/TR/xlink/#show-att) that the
application should:

  "load the resource in the same window, frame, pane, or other
relevant presentation context in which the starting resource was
loaded"

the SVG spec for the target attribute says:

  "This attribute has applicability when there are multiple possible
targets for the ending resource"

The point is that for xlink:show="replace" there is only ONE possible
target for the ending resource, thus, the target attribute should not
have applicability (and be ignored).

HOWEVER,  the one chink in my armour here is that the SVGT1.2 spec
tries to clarify things by saying
(http://www.w3.org/TR/SVGMobile12/linking.html#xlinkRefAttrs) that the
xlink:show attribute:

  "is provided for backwards compatibility with SVG 1.1. It provides
documentation to XLink-aware processors. In case of a conflict, the
target attribute has priority, since it can express a wider range of
values"

So for SVG 1.1, what was the intention?  Based on the test case
description it seems the latter SVGT 1.2 definition might apply (new
frame should open because "foo" is an invalid target), yet the SVG 1.1
spec seems pretty clear that the target attribute has no
"applicability" in the case of xlink:show="replace".

I would like this added to the issues list and make its way into the
SVG 1.1 errata.

Regards,
Jeff

Received on Tuesday, 25 September 2007 15:54:25 UTC