Use the value of a variable in the mode of apply-templates

Question

I want to apply a template with a mode that depends on a variable value.

<xsl:variable name="mode" select="@attribute"/>
<xsl:apply-templates mode="{$mode}"/>

I get the error that the stylesheet cannot be compiled. The value of mode should be a QName, but it is "{$mode}".

Is there a possibilty to use modes dependent on variables?

Answer 1

The only option you have to use a certain mode based on an expression is to use

<xsl:choose>
   <xsl:when test="@attribute = 'foo'">
      <xsl:apply-templates mode="bar"/>
   </xsl:when>
   <xsl:otherwise>
      <xsl:apply-templates/>
   </xsl:otherwise>
</xsl:choose>

or the same with an xsl:if. The mode attribute value itself needs to be a QName in XSLT 1.0 respectively in XSLT 2.0 allows a QName or special tokens like #current or #default'. But you can't compute a mode value at run-time.

Answer 2

mode is not a valid candidate for Attribute Value Templates (AVT). You simply can't do this.

From the XSLT 2.0 spec:

[Definition: In an attribute that is designated as an attribute value template, such as an attribute of a literal result element, an expression can be used by surrounding the expression with curly brackets ({})].

mode is not designated as AVT in the spec, so ou can't do this.