我如何在Diazo中切片字符串？

Question

I'd like to get only the two-digit day from a default Events portlet. That'd be "13" in the example below:

<dl class="portlet portletEvents">
    <dt class="portletHeader"><a href="/mysite/events_listing">Next events</a></dt>    
    <dd class="portletItem">
        <a title="" href="/mysite/events/my-event">Example event</a>
        <span class="portletItemDetails"><span>13/04/2012 - 22/04/2012</span></span>
    </dd>
    <dd class="portletFooter"><a href="/mysite/events_listing">Next events…</a></dd>
</dl>

At root rules level I tried:

<replace css:theme="#event-day strong">
  <xsl:template css:match="dl.portletEvents .portletItemDetails span">
    <xsl:value-of select="substring(.,1,2)" />
  </xsl:template>
</replace>

And also:

<replace css:theme="#event-day strong">
  <xsl:value-of css:select="substring(dl.portletEvents .portletItemDetails span,1,2)" />
</replace>

None of which worked. What should I do?

Answer 1

It's possible, but ugly:

<copy css:theme="#event-day strong">
   <xsl:value-of select="substring((//dl[contains(concat(' ', normalize-space(@class), ' '), ' portletEvents ')]//span[contains(concat(' ', normalize-space(@class), ' '), ' portletItemDetails ')]/span/text()),1,2)"/>
</copy>

Answer 2

This is probably something you're better off achieving by modifying the underlying Events portlet. But one of the true Diazo wizards may have a way.