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>