As David C and Martin suggest, write the sort key computation as a single
XPath expression if you can.

In the rare cases where you can't, call out to a function: compute the sort
key in a separate xsl:function, and call the function in xsl:sort/@select.

Michael Kay
Saxonica

> On 16 Mar 2021, at 16:08, Dave Pawson dave.pawson@xxxxxxxxx
<xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> xml
>
> <term>
> <fr sort="">sourire</fr>
> ...
>  </term>
>
> context is term
> I want to sort on fr/@sort
>  or (if empty)
> <xsl:value-of select="(lower-case(substring(fr,1,1)))"/>
>
> error XTSE0010 Within xsl:for-each, xsl:sort elements must come before
> other instructions
>
>  <xsl:for-each select="term">
>   <xsl:variable name='sort'>
>    <xsl:choose>
>      <xsl:when test="fr/@sort">
> <xsl:value-of select="fr/@sort"/>
>      </xsl:when>
>      <xsl:otherwise>
> <xsl:value-of select="(lower-case(substring(fr,1,1)))"/>
> </xsl:otherwise>
>    </xsl:choose>
>    </xsl:variable>
>
>
> <xsl:sort select="$sort"/>
>
>
> Any suggestions for a workaround please?
>
> TiA
>
>
> --
> Dave Pawson
> XSLT XSL-FO FAQ.
> Docbook FAQ.