Is it possible to navigate to the parent node of a matched node during XSLT processing?

I'm working with an OpenXML document, processing the main document part with some XSLT.

I've selected a set of nodes via

<xsl:template match="w:sdt">
</xsl:template>

In most cases, I simply need to replace that matched node with something else, and that works fine.

BUT, in some cases, I need to replace not the w:sdt node that matched, but the closest w:p ancestor node (ie the first paragraph node that contains the sdt node).

The trick is that the condition used to decide one or the other is based on data derived from the attributes of the sdt node, so I can't use a typical xslt xpath filter.

I'm trying to do something like this

<xsl:template match="w:sdt">
  <xsl:choose>
    <xsl:when test={first condition}> 
        {apply whatever templating is necessary}
    </xsl:when> 
    <xsl:when test={exception condition}> 
      <!-- select the parent of the ancestor w:p nodes and apply the appropriate templates -->
      <xsl:apply-templates select="(ancestor::w:p)/.." mode="backout" />
    </xsl:when> 
  </xsl:choose> 
</xsl:template>


<!-- by using "mode", only this template will be applied to those matching nodes
     from the apply-templates above -->
<xsl:template match="node()" mode="backout">
  {CUSTOM FORMAT the node appropriately}
</xsl:template>

This whole concept works, BUT no matter what I've tried, It always applies the formatting from the CUSTOM FORMAT template to the w:p node, NOT it's parent node.

It's almost as if you can't reference a parent from a matching node. And maybe you can't, but I haven't found any docs that say you can't

Any ideas?

Solution

This:

<xsl:apply-templates select="(ancestor::w:p)/.." mode="backout" />

will find all w:p elements that are ancestors of the context node, and apply templates to the parent elements of each. It sounds to me like maybe what you want to do is find only the nearest ancestor, e.g.:

<xsl:apply-templates select="ancestor::w:p[1]/.." mode="backout" />

But what you're describing here should be working, in some fashion. You should probably verify that what you think is happening is actually what's happening, by replacing your backout template with something more diagnostic, e.g.:

<xsl:template match="node()" mode="backout">
   <xsl:text>backout matched a </xsl:text>
   <xsl:value-of select="name()"/>
   <xsl:text> element.</xsl:text>
</xsl:template>