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Re: [xsl] template matching with modes, not seeing what I expect

2020-03-15 13:23:48
Hey Trevor,

To add to your XPath arsenal, consider also the XPath 2.0 functions
exists() and empty().

Where you have, for example, not(not(section)), you might wish to
rewrite as not(empty(child::section)) which is indeed the same as
exists(child::section). This might help to expose all the logic.

Additionally, we have operators in XPath 2.0

union - same as | - e.g. (title union section)
except - I mentioned (* except title)
intersect  - works as you would expect --

and also the "is" operation for node identity ...

Mulberry Technologies Inc. Quick Reference to XPath 2.0:
http://mulberrytech.com/quickref/xpath2.pdf

Cheers, Wendell

On Sun, Mar 15, 2020 at 2:07 PM Trevor Nicholls
trevor(_at_)castingthevoid(_dot_)com 
<xsl-list-service(_at_)lists(_dot_)mulberrytech(_dot_)com>
wrote:

Well the good news is that the simple test example I just created for you
did copy the input document, although the subsects attributes were not all
correctly filled in. While I work on chasing down the programming error that
must be buried in there somewhere, I still have the problem of why my simple
example incorrectly sets the attribute.

Adding debug content has shown that my test message is correctly
constructing the temporary structure, so this problem lies in my tests for
the type of content.

Given this for $tempstruct:

<section>
  <title />
  <section />
  <section />
</section>

the attribute should be "all"

Given this:

<section>
  <title />
  <para />
  <table />
  <para />
  <img />
</section>

the attribute should be "none"

and given this:

<section>
  <title>
  <section />
  <section />
  <para />
  <section />
</section>

the attribute should be "mixed"

The process I am using to try to get this result is ($tempstruct is passed
in as the parameter "top"):

<xsl:template name="testsections">
  <xsl:param name="top" />
  <xsl:for-each select="$top/*">
    <xsl:choose>
      <xsl:when test="not(section)"><xsl:text>none</xsl:text></xsl:when>
      <xsl:when test="not(not(section) and
not(title))"><xsl:text>all</xsl:text></xsl:when>
      <xsl:otherwise><xsl:text>mixed</xsl:text></xsl:otherwise>
    </xsl:choose>
  </xsl:for-each>
</xsl:template>

This template correctly identifies the all and none options, but returns
"all" instead of "mixed" for the last example.

Tested on my full document (which has several hundred sections) I can see
that all the "all" sections and all the "none" sections are correct, and all
the "mixed" sections are erroneously reported as "all".

I thought the test "not(not(section) and not(title))" would be true for all
elements that had only title and section children. Evidently that's not
true.

I tried the test "child::*[not(self::title)][not(self::section)]" as an
alternative, but that performed even worse.

I've missed some subtlety in evaluating presence and absence of specific
child elements, and it's probably in an FAQ somewhere, but if it is I missed
it.

cheers
T



-----Original Message-----
From: Martin Honnen martin(_dot_)honnen(_at_)gmx(_dot_)de
<xsl-list-service(_at_)lists(_dot_)mulberrytech(_dot_)com>
Sent: Monday, 16 March 2020 0:53
To: xsl-list(_at_)lists(_dot_)mulberrytech(_dot_)com
Subject: Re: [xsl] template matching with modes, not seeing what I expect

Am 15.03.2020 um 11:04 schrieb Trevor Nicholls 
trevor(_at_)castingthevoid(_dot_)com:

I'm testing a simple stylesheet which implements a suggestion made in
reply to my previous approach, i.e. that I could process the output of
a document into a variable to test. When the stylesheet is just
reporting the results, it works just fine, but when I combine it with
templates which copy the input document and replace one attribute
based on those tests, the input document is not being copied.

But if I run this stylesheet and give it an input file (with no
subsects
attributes) which contains a parent with multiple sections and mixed
content, only the first section is output with the attribute
(incorrectly set to "none"), and the rest of the output XML is the
result of the mode="check" versions of the templates, i.e. the only
output is the initial XML header followed by a copy of the $tempstruct
variable built when the context node is the top level element of the
input document.. The default templates simply aren't executed.

Can you show us a minimal sample input together with the output you get and
then one you want?






-- 
...Wendell Piez... ...wendell -at- nist -dot- gov...
...wendellpiez.com... ...pellucidliterature.org... ...pausepress.org...
...github.com/wendellpiez... ...gitlab.coko.foundation/wendell...
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