How to test if an xml tag is 3 char long and uppercase with XSL

Question

I am trying to transform an XML file with XSL and I need to test if a tag is 3 character long and uppercase. The XML file I am trying to transform (and I have no control over the format of this) looks like this:

<RECORD>
   <AAA>
       <c01>1</c01>
       <c02>2</c02>
   </AAA>
   <BBB>
       <c01>3</c01>
       <c02>4</c02>
   </BBB>
</RECORD>

And I need to separate the AAA and BBB tags with ":" so I get something like

AAA:1+2;BBB:3+4;

However, AAA and BBB can be practically any 3 letter combination. Otherwise I could have done something like this.

<xsl:param name="X">AAA:BBB:CCC</xsl:param>
<xsl:for-each select="//*[contains($X, substring(local-name(), 1, 3))]">

I have found xsl functions uppercase and lowercase, but nothing to test the case in a simple way. Does anyone know how to achieve this, without making it too complicated?

Answer 1

If you can use XSLT 2.0, you can use the matches function to make use of regular expressions

 <xsl:for-each select="//*[matches(local-name(), '^[A-Z]{3}$')]">

In XSLT 1.0, it is a little more work, but you could do something like this...

<xsl:for-each select="//*[string-length(local-name()) = 3 and translate(local-name(), 'ABCDEFGHIJKLMNOPQRSTUVWXYZ', '') = '']">