Re: [xsl] Parameter evaluation after use of document()

[Yves Forkl <Yves dot Forkl at gmx dot net>]

Hi Oleg,

Oleg Tkachenko wrote:

> Yves Forkl wrote:
>
> > I am wondering why the XSLT code below doesn't work. Xalan-J dies with
> > the (not very helpful) errors mentioned below as soon as it tries to
> > get the value of "filename_base" in the second last line in the
> > stylesheet excerpt.
> 
> >   <xsl:apply-templates
> >     select="document(concat($filename_base, '.xml'))"
> >     mode="info_mode">
> 
> Applying templates directly to a result of document() function can be
> dangerous sometime due to the fact that the result is always root node
> and template for "/" is in use. Without a mode it could cause infinite
> looping, in your case you probably don't have template for root node in
> info_mode mode and built-in template as usual loses your parameter.
> Try to add some location path after document() function to eliminate
> built-in templates processing as they don't pass parameters.

I followed your suggestion exactly (see updated stylesheet excerpt
below): now
I only receive one type of error (InvocationTargetException),
occurring where I'm calling the template on the other input document's
content while trying to pass a parameter.

Even indicating the document's root _element_ didn't change the
situation; anyway, I would prefer a generic template like it can be
seen below. I also added an info_mode template for the root of that
document that also passes the parameter (see below), but it didn't
change anything.

How can I get the parameter through to the template which is
processing my "side" input document?


> But anyway it's perfectly legal xslt stylesheet and xalan shouldn't die
> on it, probably you have found a bug.

So, is there some Xalan expert out there to tell if the fatal error
after "loosing" all parameters when reading from document() might be a
Xalan bug? (Version: Xalan-Java 2.2.D13.)

I join the updated versions of my snippets for completeness.

  Cheers,

    Yves

++++++++++ content of file "Chapter_1.xml" ++++++++++

<?xml version="1.0" encoding="iso-8859-1"?>
<!-- ... -->
<!-- ... -->
<chapter id="Chapter1_ID">
<title>My First Chapter</title>
...
</chapter>

++++++++++ excerpt of stylesheet ++++++++++

<!-- value of $type is not relevant -->

<!-- process all element nodes of type $type -->
<xsl:for-each select="key('select_nodes_by_type', $type)">
  <xsl:call-template name="generic_info_template">
    <!-- extract the text node of the each element node of type $type
-->
    <xsl:with-param name="filename_base" select="text()"/>
    <!-- SUPPOSE: 1st run: $filename_base = "Chapter_1" -->
  </xsl:call-template>
</xsl:for-each>

<!-- apply appropriate info_mode templates to file contents -->
<xsl:template name="generic_info_template">
  <xsl:param name="filename_base"/>
  <!-- read in file contents and process them in info_mode -->
  <xsl:apply-templates
    select="document(concat($filename_base, '.xml'))/*"
    mode="info_mode">
    <!-- hand the param to the called template -->
    <xsl:with-param name="filename_base"
      select="$filename_base"/>
  </xsl:apply-templates>
</xsl:template>

<!-- dummy template for root node of included document -->
  <xsl:template match="/" mode="info_mode">
    <xsl:apply-templates mode="info_mode">
      <xsl:with-param name="filename_base"
        select="$filename_base"/>
    </xsl:apply-templates>
  </xsl:template>

<!-- write out info specifically for chapter nodes -->
<xsl:template match="chapter" mode="info_mode">
  <xsl:param name="filename_base"/>
  <xsl:text>This chapter's title: </xsl:text>
  <xsl:value-of select="title"/>
  <xsl:text>
This chapter's filename base: </xsl:text>
  <xsl:value-of select="$filename_base"/>
</xsl:template>

++++++++++ fatal error messages by Xalan-J ++++++++++

  (Location of error unknown)XSLT Error
  (javax.xml.transform.TransformerException)
  : java.lang.reflect.InvocationTargetException

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