Problem sorting RSS feed by date using XSL

Question

I'm creating a website where I need to show the top 5 records from an RSS feed, and these need to be sorted by date and time.

The date fields in the RSS feed are in the following format: "Mon, 16 Feb 2009 16:02:44 GMT"

I'm having big problems getting the records to sort correctly - I've tried lots of different code examples I've seen, but none seem to sort the records correctly. The code for my XSL sheet is shown below, and the feed in question is here.

Very grateful for anyones help!!!

Thanks,

Chris.

---

XSL CODE:

<xsl:stylesheet version="1.1" 
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:digg="http://digg.com//docs/diggrss/"
xmlns:dc="http://purl.org/dc/elements/1.1/">
<xsl:template match="/">    
<xsl:for-each select="//*[local-name()='item'][position() < 6]">    
    <p>
        <a>
        <xsl:attribute name="href">
        <xsl:value-of select="*[local-name()='link']"/></xsl:attribute>
        <xsl:attribute name="target">
        <xsl:text>top</xsl:text>
        </xsl:attribute>
        <xsl:value-of select="*[local-name()='title']"/>
        </a>
        <br/>
    <span class="smaller"><xsl:value-of select="*[local-name()='pubDate']" disable-output-escaping="yes"/></span>
    </p>
</xsl:for-each>

Answer 1

An other way to get around the document restriction is to use the following:

<xsl:template name="getMonth">
    <xsl:param name="name" />
    <xsl:choose>
        <xsl:when test="$name = 'Jan'">01</xsl:when>
        <xsl:when test="$name = 'Feb'">02</xsl:when>
        <xsl:when test="$name = 'Mar'">03</xsl:when>
        <xsl:when test="$name = 'Apr'">04</xsl:when>
        <xsl:when test="$name = 'May'">05</xsl:when>
        <xsl:when test="$name = 'Jun'">06</xsl:when>
        <xsl:when test="$name = 'Jul'">07</xsl:when>
        <xsl:when test="$name = 'Aug'">08</xsl:when>
        <xsl:when test="$name = 'Sep'">09</xsl:when>
        <xsl:when test="$name = 'Oct'">10</xsl:when>
        <xsl:when test="$name = 'Nov'">11</xsl:when>
        <xsl:when test="$name = 'Dec'">12</xsl:when>
        <xsl:otherwise>99</xsl:otherwise>
    </xsl:choose>
</xsl:template>

Called using

   <xsl:call-template name="getMonth">
       <xsl:with-param name="name" select="substring(./pubDate,9,3)" />
   </xsl:call-template>

It's not pretty, but at least you don't have to worry about security

Answer 2

The following transformation:

<xsl:stylesheet version="1.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:output omit-xml-declaration="yes" indent="yes"/>

  <xsl:variable name="vrtfMonths">
    <m name="Jan" num="01"/>
    <m name="Feb" num="02"/>
    <m name="Mar" num="03"/>
    <m name="Apr" num="04"/>
    <m name="May" num="05"/>
    <m name="Jun" num="06"/>
    <m name="Jul" num="07"/>
    <m name="Aug" num="08"/>
    <m name="Sep" num="09"/>
    <m name="Oct" num="10"/>
    <m name="Nov" num="11"/>
    <m name="Dec" num="12"/>
  </xsl:variable>

  <xsl:variable name="vMonths" select=
   "document('')/*/xsl:variable
                   [@name='vrtfMonths']/*"
   />

    <xsl:template match="channel">
      <xsl:for-each select="item">
        <xsl:sort data-type="number" order="descending" select=
        "concat(substring(pubDate,13,4),
                $vMonths[@name 
                        = 
                         substring(current()/pubDate,9,3)]/@num,

                substring(pubDate,6,2),
                translate(substring(pubDate,18,8),
                          ':',
                          ''
                          )
                )
         "/>

         <xsl:if test="not(position() > 5)">
           <xsl:copy-of select="."/>

         </xsl:if>
      </xsl:for-each>
    </xsl:template>
</xsl:stylesheet>

when applied on the provided source XML document (too-long to list here, see the link),

produces the wanted result:

<item xmlns:media="http://search.yahoo.com/mrss">
        <title>Inflation rate expected to fall</title>
        <description>The latest figures for the rate of inflation, for the 12 months to January, are expected to show that it has fallen again.</description>
        <link>http://news.bbc.co.uk/go/rss/-/1/hi/business/7893873.stm</link>
        <guid isPermaLink="false">http://news.bbc.co.uk/1/hi/business/7893873.stm</guid>
        <pubDate>Tue, 17 Feb 2009 02:58:03 GMT</pubDate>
        <category>Business</category>
        <media:thumbnail width="66" height="49" url="http://newsimg.bbc.co.uk/media/images/45483000/jpg/_45483998_cash226.jpg" />
    </item><item xmlns:media="http://search.yahoo.com/mrss">
        <title>Farming pressures</title>
        <description>Are farmers being forced to use GM seeds?</description>
        <link>http://news.bbc.co.uk/go/rss/-/1/hi/business/7892328.stm</link>
        <guid isPermaLink="false">http://news.bbc.co.uk/1/hi/business/7892328.stm</guid>
        <pubDate>Tue, 17 Feb 2009 00:06:31 GMT</pubDate>
        <category>Business</category>
        <media:thumbnail width="66" height="49" url="http://newsimg.bbc.co.uk/media/images/45481000/jpg/_45481936_005666785-1.jpg" />
    </item><item xmlns:media="http://search.yahoo.com/mrss">
        <title>Engine room?</title>
        <description>Western Australia's economy may be hitting reverse. </description>
        <link>http://news.bbc.co.uk/go/rss/-/1/hi/business/7840370.stm</link>
        <guid isPermaLink="false">http://news.bbc.co.uk/1/hi/business/7840370.stm</guid>
        <pubDate>Tue, 17 Feb 2009 00:05:25 GMT</pubDate>
        <category>Business</category>
    </item><item xmlns:media="http://search.yahoo.com/mrss">
        <title>Coining it in? </title>
        <description>Investors turning to old and rare coins in the downturn </description>
        <link>http://news.bbc.co.uk/go/rss/-/1/hi/business/7878606.stm</link>
        <guid isPermaLink="false">http://news.bbc.co.uk/1/hi/business/7878606.stm</guid>
        <pubDate>Tue, 17 Feb 2009 00:04:29 GMT</pubDate>
        <category>Business</category>
        <media:thumbnail width="66" height="49" url="http://newsimg.bbc.co.uk/media/images/45459000/jpg/_45459789_dsc_4982.jpg" />
    </item><item xmlns:media="http://search.yahoo.com/mrss">
        <title>Home sales may rise say surveyors</title>
        <description>Property sales may pick in the next few months, according to the Royal Institution of Chartered Surveyors (Rics).</description>
        <link>http://news.bbc.co.uk/go/rss/-/1/hi/business/7893193.stm</link>
        <guid isPermaLink="false">http://news.bbc.co.uk/1/hi/business/7893193.stm</guid>
        <pubDate>Tue, 17 Feb 2009 00:02:19 GMT</pubDate>
        <category>Business</category>
        <media:thumbnail width="66" height="49" url="http://newsimg.bbc.co.uk/media/images/45483000/jpg/_45483075_006771638-1.jpg" />
    </item>