XSLT: Get Latest Date

Question

I have a structure like this:

<Info ID="1"> ... <Date>2009-04-21</Date> </Info> <Info ID="2"> ... <Date>2009-04-22</Date> </Info> <Info ID="3"> ... <Date>2009-04-20</Date> </Info> 

I want to get the latest date using XSLT (in this example, 2009-04-22).

Answer 1

I realized that it was not as difficult as I thought it would be:

  <xsl:variable name="latest"> <xsl:for-each select="Info"> <xsl:sort select="Date" order="descending" /> <xsl:if test="position() = 1"> <xsl:value-of select="Date"/> </xsl:if> </xsl:for-each> </xsl:variable> <xsl:value-of select="$latest"/> 

Answer 2

XSLT 2.0+: <xsl:perform-sort> used when we want to sort the elements without processing the elements individually. <xsl:sort> used to process elements in sorted order. Since you just need the latest date in this case, you do not need to process each <Info> element. Use <xsl:perform-sort> :

 <xsl:variable name="sorted_dates"> <xsl:perform-sort select="Info/Date"> <xsl:sort select="."/> </xsl:perform-sort> </xsl:variable> <xsl:value-of select="$sorted_dates/Date[last()]"/> 

Answer 3

In XSLT 2.0 or later, you do not need to sort at all; you can use max() ...

 <xsl:value-of select="max(//Date/xs:date(.))"/>