I am a relative noob when it comes to XSLT and I need some help with a match expression. I need to match a set (any length) of elements that all begin with the same text in the node name. Example:

<person>
   <phone1AC />
   <phone1Exc />
   <phone1Num />

   <phone2AC />
   <phone2Exc />
   <phone2Num />

   <lastName />
   <firstName />
   <etc />
</person>

I need a match expression which matches the 3 'phone1' nodes and then (again) the 3 'phone2' nodes but not the 'lastName', 'firstName' or 'etc' nodes. I _CAN_ know the prefixes ('phone1', 'phone2') in advance, but it would be even better if the match expression matched arbitrary begins-with strings.... is that too much to ask?

Thanks very much in advance,

=dave=

Your terminology isn't quite right, unfortunately, which means I might be misunderstanding your problem. There are two separate things in XSLT: a pattern, also called a match pattern, which is used in the "match" attribute of xsl:template, and an expression, also called an XPath expression or select expression, used for example in the "select" attribute of instructions like xsl:apply-templates and xsl:value-of. I'm not sure which of these you mean by "match expression".

It's easy enough to match on a fixed prefix, for example

<xsl:template match="*[starts-with(name(), 'phone']">

or

<xsl:for-each select="*[starts-with(name(), 'phone']">

In a select expression you can also use a variable:

<xsl:for-each select="*[starts-with(name(), $prefix]">

In XSLT 2.0 you can also do this in a match pattern:

<xsl:template match="*[starts-with(name(), $prefix]">

However, XSLT 1.0 doesn't allow variables in match patterns.

A general point about your XML design: I think it's trying to pack too much information into the names of the elements. It would be much cleaner to use a hierarchic structure:

<person>
   <phone nr="1">
      <AC/>
      <Exc />
      <Num />
   </phone>
   <phone nr="2">
      <AC/>
      <Exc />
      <Num />
   </phone>
   <lastName />
   <firstName />


Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference

Thanks Michael, you have sent me in a couple of directions that seem promising.

Your suggestion to change the structure of the input is a good one....sadly, I cannot change the DTD of the input XML.

You have confused me a bit. I was under the impression that an "XPath expression" could be used as a "match pattern." I never gave it much thought, but I guess I also thought the reverse was true. In your example:

<xsl:template match="*[starts-with(name(), 'phone']">

or

<xsl:for-each select="*[starts-with(name(), 'phone']">

The two look remarkably similar, to me. Can you point me toward a resource that explains the differences (you mentioned one difference in your reply... there are others?)?

I had it in my head that I was looking for a "match pattern" because I thought I wanted to use templates. My current thought is that using a "choose" with an "xpath expression" is probably a better way to go, in this particular case.

Thanks very much for your prompt (and useful) response.

=dave=

>Can you point me toward a resource that explains the differences

(a) the spec (search for XSLT 1.0 Recommendation or XSLT 2.0 Recommendation)

(b) my book (since we're on a Wrox site).

Match patterns are essentially a subset of XPath expressions.



Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference