Michael Kay wrote:
Specifically, the XSLT spec suggests that when using the HTML
output method, that the XSLT processor do some escaping of
*non-ASCII* characters in the href, src, codebase, or other
URI-type attribute value. The XSLT processor is not required
to do so -- in my opinion, it shouldn't bother, because it is
the author's responsibility to ensure that the value is a URI
reference, not an IRI.
The spec uses the word "should" throughout the section on serialization.
My interpretation is that this is because serialization is optional, not
because all the individual aspects of serialization are mere
suggestions.
Given the complete absence of the word "must" in that section, I considered
your interpretation as well, but then I thought "Surely James Clark wouldn't
have left it ambiguous. Should means should, not must -- simple as that." It
would not have confused matters any if "must" were used, since it would
phrased as "the HTML output method must do x y and z", which does not
contradict the optional-ness of support for the HTML output method or any
other hints provided by xsl:output.
I've also seen specs that try to define rather more clearly what they
mean by "should": specifically: "should do X" means "must do X unless
there is a good documented reason not to do so in the particular
circumstances". It certainly doesn't mean "could do X if you feel like
it".
"Should" might also be used when the specification would like to make it be a
"must" but does not want to impose a burden on the implementations, such as
when you allow extension functions to inject into your result tree string
objects that contain illegal characters. :)
Mike
--
Mike J. Brown | http://skew.org/~mike/resume/
Denver, CO, USA | http://skew.org/xml/
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