RE: [docbook-apps] Request for help with XSL: template for proces singinstruction not getting called

[Taro Ikai <tikai@ABINITIO.COM>]

First, I just got it to work, but here's some additional information on 
what I was doing.

Jeff Beal <jeff.beal@ansys.com> wrote on 10/03/2003 08:48:37 AM:
> You're right.  There shouldn't be any overlap between these two 
templates.
> Which processor are you using?

I'm using xsltproc.

To give you more information, here are the two templates in my 
customization layer:

<xsl:import href="/usr/share/docbook-xsl/htmlhelp/htmlhelp.xsl"/>

<xsl:template match="processing-instruction('dbhh')" mode="hh-alias">
  <xsl:variable name="topicname">
    <xsl:call-template name="pi-attribute">
      <xsl:with-param name="pis" select="."/>
      <xsl:with-param name="attribute" select="'topicname'"/>
    </xsl:call-template>
  </xsl:variable>
  <xsl:variable name="href">
    <xsl:call-template name="href.target.with.base.dir">
      <xsl:with-param name="object" select=".."/>
    </xsl:call-template>
  </xsl:variable>
  <xsl:value-of select="$topicname"/>
  <xsl:text>=</xsl:text>
  <xsl:value-of select="substring-before(concat($href, '#'), 
'#')"/>#<xsl:value-of select="$topicname"/>
  <xsl:text>&#xA;</xsl:text>
</xsl:template>

<xsl:template match="*" mode="hh-alias">
  <xsl:if test="@id">
    <xsl:value-of select="@id"/>
    <xsl:text> = </xsl:text>
    <xsl:call-template name="href.target"/>
    <xsl:text>&#xA;</xsl:text>
  </xsl:if>
  <xsl:apply-templates select="*" mode="hh-alias"/><!-- recurse into 
subelements -->
</xsl:template>

My customization layer imports the htmlhelp.xsl stylesheet, which in turn 
includes htmlhelp-common.xsl, where the following templates are defined:

<xsl:template name="hh-alias">
  <xsl:call-template name="write.text.chunk">
    <xsl:with-param name="filename">
      <xsl:if test="$manifest.in.base.dir != 0">
        <xsl:value-of select="$base.dir"/>
      </xsl:if>
      <xsl:value-of select="$htmlhelp.alias.file"/>
    </xsl:with-param>
    <xsl:with-param name="method" select="'text'"/>
    <xsl:with-param name="content">
     <xsl:choose>
       <xsl:when test="$rootid != ''">
         <xsl:apply-templates select="key('id',$rootid)" mode="hh-alias"/>
       </xsl:when>
       <xsl:otherwise>
         <xsl:apply-templates select="/" mode="hh-alias"/>
       </xsl:otherwise>
     </xsl:choose>
    </xsl:with-param>
    <xsl:with-param name="encoding" select="$htmlhelp.encoding"/>
  </xsl:call-template>
</xsl:template>

<xsl:template match="processing-instruction('dbhh')" mode="hh-alias">
  <xsl:variable name="topicname">
    <xsl:call-template name="pi-attribute">
      <xsl:with-param name="pis"
                      select="."/>
      <xsl:with-param name="attribute" select="'topicname'"/>
    </xsl:call-template>
  </xsl:variable>
  <xsl:variable name="href">
    <xsl:call-template name="href.target.with.base.dir">
      <xsl:with-param name="object" select=".."/>
    </xsl:call-template>
  </xsl:variable>
  <xsl:value-of select="$topicname"/>
  <xsl:text>=</xsl:text>
  <!-- Some versions of HH doesn't like fragment identifires, but some 
does. -->
  <!-- <xsl:value-of select="substring-before(concat($href, '#'), '#')"/> 
-->
  <xsl:value-of select="$href"/>
  <xsl:text>&#xA;</xsl:text>
</xsl:template>

<xsl:template match="text()" mode="hh-alias"/>

Joerg asked:
> Is the template 
>matching on elements called *instead* of the original template matching 
>on this specific processing instruction? If I don't miss anything it 

Yes. The rule <xsl:template match="processing-instruction('dbhh')" 
mode="hh-alias">
gets called only if I don't have <xsl:template match="*" mode="hh-alias"> 
rule.

Jirka asked:
>And how does this template looks. It must contain <xsl:apply-templates/> 
>in order to invoke templates for child nodes including PI nodes.

As you see in my <xsl:template match="*" mode="hh-alias">, it does
call <xsl:apply-templates select="*" mode="hh-alias"/>.

*** At this point, I realized this is the problematic line.
The select expression "*" does not catch processing instructions.

If I say simply <xsl:apply-templates/>, the processing does not seem
to recurse correctly. I only get output from the root node.
I don't know why. Perhaps someone can teach me why.

When I tried this I was successful:

  <xsl:apply-templates mode-"hh-alias"/>

The following also works:

  <xsl:apply-templates select="*|processing-instruction()" 
mode-"hh-alias"/>

So the XSL lesson I learned was that "*" does not match processing 
instructions.
But I still don't know why the simple rule <xsl:apply-templates/> does not
recurse into child nodes.

-Taro