Re: [xsl] Copy-per-default

[Brandon Ibach <brandon.ibach@xxxxxxxxxxxxxxxxxxx>]

Most (probably all, though I think we'd need more details on the
latter issue) of the behavior you're seeing can be explained by XSLT's
built-in templates.  See section 5.8 of the XSLT 1.0 specification
[1], but in short, they are:

<xsl:template match="*|/">
  <xsl:apply-templates/>
</xsl:template>

<xsl:template match="*|/" mode="m"><!-- One of these for each mode -->
  <xsl:apply-templates mode="m"/>
</xsl:template>

<xsl:template match="text()|@*">
  <xsl:value-of select="."/>
</xsl:template>

<xsl:template match="processing-instruction()|comment()"/>

-Brandon :)

[1] http://www.w3.org/TR/1999/REC-xslt-19991116#built-in-rule

On Wed, Apr 20, 2011 at 11:24 AM, Fredrik Bengtsson
<Fredrik.Bengtsson@xxxxxxxxxxxx> wrote:
> Hi,
>
> I am using FOP trunk to generate PDFs from DocBook documents on the command
line. Fop.bat is doing the XSL transformation, using whatever engine fop uses
(xalan?). I have written the XSLT entirely by myself, i.e. I am not using any
default DocBook transform or similar. The transform is small and under my
strict control.
>
> I am having the problem that the transform does not behave as expected in
two ways:
> * Contents of nodes are being copied to the output as if there were some
kind of identity transform in effect by default even though I have not written
one, and
> * Matches far down in the document cannot fetch data that existed earlier in
the document, as if select="/x" selected the x post-transform instead of
pre-transform
>
>
> Imagine a document like this (ignoring namespaces etc for brevity):
>
> <book>
>  <titleabbrev>THEDOC</titleabbrev>
>  <chapter>
>    <title>Ch. 2: The chapter</title>
>    <titleabbrev>Ch. 2</titleabbrev>
>  </chapter>
> </book>
>
>
> If I have the following transforms in place:
>
> <xsl:template match="/d:book">
>  <!-- ignoring root, page-sequence etc for brevity -->
>  <xsl:apply-templates />
> </xsl:template>
>
> <xsl:template match="d:chapter">
>  <xsl:apply-templates />
> </xsl:template>
>
> <xsl:template match="d:chapter/d:title">
>  <fo:block> ... ... </fo:block>
> </xsl:template>
>
>
> Then for some reason the titleabbrev appears in the output even though I
have not made any rule explicitly matching it. It is caught along with the
title inside the apply-templates under d:chapter. I thought that this would
not happen, unless I really added a matching template of some sort, for
example an identity transform.
>
>
> I then just for fun tried to add the following template:
>
> <xsl:template match="*" />
>
>
> That got rid of the offending titleabbrev, BUT it also had the effect of
breaking another template that special-cases the first chapter:
>
> <xsl:template match="d:chapter[1]">
>  <xsl:variable name="abbr">
>    <xsl:value-of select="/d:book/d:titleabbrev" />
>  </xsl:variable>
>  <!-- note: that selects a node that is higher up in the document -->
>  <!-- now do something with $abbr -->
> </xsl:template>
>
>
> It seems that at that point, book/titleabbrev has already been transformed,
i.e. removed due to the catch-all template above, so $abbr is empty. That
strikes me as extremely strange; should the select not grab nodes from the
original unmodified document? If I remove the catch-all, $abbr is set properly
just as expected.
>
> This is really confusing! And again - I am not using a huge third-party
transform and modifying it, but rather using a really small, custom-written
and strict one under my control.
>
> /Fredrik