XSLT, 2nd Edition

Doing Math Without Recursion

Our original stylesheet had to use recursion to calculate the total of each purchase order. We passed all of the <item> elements to a recursive template, which returned the total for the purchase order after processing all of the <item>s. In XSLT 2.0, we can use a simple XPath expression to do all that work for us. Here’s the single line of code:

<xsl:value-of 
  select="format-number(sum(items/item/(qty * price)), 
          '$#,###.00')"/>

That’s it. XPath 2.0’s support for mathematical expressions inside path expressions makes this ridiculously easy. We replaced maybe 20 lines of code with just 1.