A quick guide on how to use sorting in XSLT to your advantage.

I was working on a custom page for a news site recently, the page had to list 3 news stories per category of the site, with a predefined order for some categories, with the rest following afterwards in alphabetical order.

So, perhaps you’re thinking:

<xsl:template match="news-categories">
    <xsl:apply-templates select="category[@handle = 'news']" mode="list" />
    <xsl:apply-templates select="category[@handle = 'opinions']" mode="list" />
    
    <!-- And then came the mob -->
    <xsl:apply-templates select="category[
        @handle != 'news'
        and @handle != 'opinions'
    ]" mode="list">
        <xsl:sort select="@handle" order="ascending" />
    </xsl:apply-templates>
</xsl:template>

Which would work, but would get kind of nasty if you need to add a third or fourth category.  Instead, here’s my solution:

<xsl:template match="news-categories">
    <xsl:apply-templates select="category" mode="list">
        <xsl:sort select="@handle = 'news'" order="descending" />
        <xsl:sort select="@handle = 'opinions'" order="descending" />
        
        <!-- And then came the mob -->
        <xsl:sort select="@handle" order="ascending" />
    </xsl:apply-templates>
</xsl:template>

Neat huh?  It forces the categories you need to the top of the list, satisfying the clients whim without them even knowing.