Effect of DTD declaration on XSL processing?

07-24-2003

Test Test HTML file

Test file to observe effect of DTD declaration on XSL processing.

07-24-2003

Simon Brooke <> writes:

> (i) explain this behaviour and the reasons for it, and

Namespaces. In your XHTML with DTD, the html element and all its
descendents are in a namespace because of fixed-value attribute
declarations in the DTD. In the XHTML without DTD, the elements are
in no namespace.

In your XSLT, <xsl:template match="html"> matches only html elements
in no namespace.

> (ii) suggest a recipe for XSLT stylesheets which work irrespective
> of whether the DTD declaration is present or not?

I think the only way is change all your XPath expressions to match
against both possibilities. For example

<xsl:stylesheet xmlns

sl="http://www.w3.org/1999/XSL/Transform"
version="1.0"
xmlns:ht="http://www.w3.org/1999/xhtml">
<xsl:template match="html | ht:html">

or

<xsl:template match="*[local-name() = 'html']">

--
Dean Tiegs, NE¼-20-52-25-W4
“Confortare et esto robustus”
http://telusplanet.net/public/dctiegs/

07-24-2003

Simon Brooke wrote:
> I thought I knew this stuff. I've been teaching XML since 1998. But
> I've just stumbled on something which is so bizarre (to me) that I'm
> beginning to think I don't understand anything at all.
>
> Consider the attached files. They comprise one very simple XSL
> transform, one copy of a very simple valid XHTML file with the DTD
> declaration (without which it would not be valid), and one copy of the
> same XHTML file but with the DTD declaration removed. Note that
> with-dtd.html has been tested against the W3C validator.

According to the spezification you have no XHTML-Dokument
<http://www.w3.org/TR/xhtml1/#strict>:

3.
The root element of the document must contain an xmlns declaration for
the XHTML namespace [XMLNS]. The namespace for XHTML is defined to be
http://www.w3.org/1999/xhtml. An example root element might look like:

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
--
Johannes Koch
In te domine speravi; non confundar in aeternum.
(Te Deum, 4th cent.)

07-24-2003

Dean Tiegs <> writes:

> Simon Brooke <> writes:
>
> > (i) explain this behaviour and the reasons for it, and
>
> Namespaces. In your XHTML with DTD, the html element and all its
> descendents are in a namespace because of fixed-value attribute
> declarations in the DTD. In the XHTML without DTD, the elements are
> in no namespace.

Many thanks for that, that's clear and straightforward...

> In your XSLT, <xsl:template match="html"> matches only html elements
> in no namespace.
>
> > (ii) suggest a recipe for XSLT stylesheets which work irrespective
> > of whether the DTD declaration is present or not?
>
> I think the only way is change all your XPath expressions to match
> against both possibilities. For example
>
> <xsl:stylesheet xmlns

sl="http://www.w3.org/1999/XSL/Transform"
> version="1.0"
> xmlns:ht="http://www.w3.org/1999/xhtml">
> <xsl:template match="html | ht:html">

OK, this works. The effect on performance is quite surprising:

-[simon]-> time xsltproc test.xsl with-dtd.html
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">


real 0m11.328s
user 0m0.020s
sys 0m0.020s

-[simon]-> time xsltproc test.xsl without-dtd.html
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">


real 0m0.005s
user 0m0.000s
sys 0m0.000s

Presumably the extra time is taken fetching and parsing the DTD. I
*hate* generating code which isn't valid, but I'm going to have to
make a choice here between valid code and reasonable performance!

--
(Simon Brooke) http://www.jasmine.org.uk/~simon/

;; my other religion is Emacs

07-24-2003

In article < >,
Simon Brooke <> wrote:
>real 0m11.328s
>user 0m0.020s
>sys 0m0.020s

>real 0m0.005s
>user 0m0.000s
>sys 0m0.000s

>Presumably the extra time is taken fetching and parsing the DTD.

Fetching, since the cpu time is still only .04 seconds.

Can't you use a catalog to get a local copy instead? Or failing that
an http proxy?

-- Richard
--
Spam filter: to mail me from a .com/.net site, put my surname in the headers.

FreeBSD rules!

07-25-2003

(Richard Tobin) writes:

> In article < >,
> Simon Brooke <> wrote:
> >real 0m11.328s
> >user 0m0.020s
> >sys 0m0.020s
>
> >real 0m0.005s
> >user 0m0.000s
> >sys 0m0.000s
>
> >Presumably the extra time is taken fetching and parsing the DTD.
>
> Fetching, since the cpu time is still only .04 seconds.
>
> Can't you use a catalog to get a local copy instead? Or failing that
> an http proxy?

Not reliably, in all the places this software runs. However, it turns
out not to matter very much because in the real application the time
hit occurs only the first time the DTD declaration is seen, and as
this software tends to have uptimes of more than six months a ten
second hit at startup time is not that painful. I'm just glad that I
now understand what's going on!

The only thing that bothers me is what happens if the software doesn't
have access to the public internet at all and consequently can't fetch
the DTD. Presumably it will barf horribly and I'll have to do
something about that.

The easiest thing, of course, would be to not generate the DTD
declaration in the first place, but for purely aesthetic reasons I
don't want to do that!

--
(Simon Brooke) http://www.jasmine.org.uk/~simon/

;; my other religion is Emacs

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