Re: [xsl] in-document references

[Jeni Tennison <jeni@xxxxxxxxxxxxxxxx>]

Hi Simon,

> I'm not sure if the word "flatten" was right. I want it to expand all 
> of the defines so that everywhere there is a "ref" it is replaced by 
> whatever is in the "define". I could pre-process the file with XSLT 
> that does that, but I'd rather skip that step since it could result in 
> a potentially very large intermediate file.

You would also run into difficulties if you ever tried to flatten a
schema for documents with a recursive structure, e.g.:

<define name="section">
  <element name="section">
    <oneOrMore>
      <ref name="paragraph" />
    </oneOrMore>
    <zeroOrMore>
      <ref name="section" />
    </zeroOrMore>
  </element>
</define>

but perhaps that won't occur in the kind of XML that you're dealing
with.

>From the sounds of it, you want to access the most recent
element/attribute element in the template for the <data> element. To
do that consistently through multiple <ref>s and <define>s, you need
to pass it as a parameter. Something like:

<xsl:key name="defines" match="rng:define" use="@name" />

<xsl:template match="rng:element">
  ...
  <xsl:apply-templates>
    <xsl:with-param name="node" select="." />
  </xsl:apply-templates>
  ...
</xsl:template>

<xsl:template match="rng:ref">
  <xsl:param name="node" />
  <xsl:apply-templates select="key('defines', @name)">
    <xsl:with-param name="node" select="$node" />
  </xsl:apply-templates>
</xsl:template>

<xsl:template match="rng:define">
  <xsl:param name="node" />
  <xsl:apply-templates>
    <xsl:with-param name="node" select="$node" />
  </xsl:apply-templates>
</xsl:template>

<xsl:template match="rng:data">
  <xsl:param name="node" />
  <xsl:value-of select="$node" />
</xsl:template>

You could pass the <ref> element through to the template for the
<define> element, but you'll start losing track of what the context is
if you go through multiple <ref>s on your way from an <element> to a
<data> element.

Cheers,

Jeni

---
Jeni Tennison
http://www.jenitennison.com/


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