How do I use a regular expression in XSLT 1.0? - regex

Question

I am using XSLT 1.0.
My input information may contain these values
<!--case 1-->
<attribute>123-00</attribute>
<!--case 2-->
<attribute>Abc-01</attribute>
<!--case 3-->
<attribute>--</attribute>
<!--case 4-->
<attribute>Z2-p01</attribute>
I want to find out those string that match the criteria:
if string has at least 1 alphabet AND has at least 1 number,
then
do X processing
else
do Y processing
In example above, for case 1,2,4 I should be able to do X processing. For case 3, I should be able to do Y processing.
I aim to use a regular expression (in XSLT 1.0).
For all the cases, the attribute can take any value of any length.
I tried use of match, but the processor returned an error.
I tried use of translate function, but not sure if used the right way.
I am thinking about.
if String matches [a-zA-Z0-9]*
then do X processing
else
do y processing.
How do I implement that using XSLT 1.0 syntax?

Answer 1

This solution really works in XSLT 1.0 (and is simpler, because it doesn't and needn't use the double-translate method.):
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="text"/>
<xsl:variable name="vUpper" select=
"'ABCDEFGHIJKLMNOPQRSTUVWXYZ'"/>
<xsl:variable name="vLower" select=
"'abcdefghijklmnopqrstuvwxyz'"/>
<xsl:variable name="vAlpha" select="concat($vUpper, $vLower)"/>
<xsl:variable name="vDigits" select=
"'0123456789'"/>
<xsl:template match="attribute">
<xsl:choose>
<xsl:when test=
"string-length() != string-length(translate(.,$vAlpha,''))
and
string-length() != string-length(translate(.,$vDigits,''))">
Processing X
</xsl:when>
<xsl:otherwise>
Processing Y
</xsl:otherwise>
</xsl:choose>
</xsl:template>
</xsl:stylesheet>
when applied on the provided XML fragment -- made a well-formed XML document:
<t>
<!--case 1-->
<attribute>123-00</attribute>
<!--case 2-->
<attribute>Abc-01</attribute>
<!--case 3-->
<attribute>--</attribute>
<!--case 4-->
<attribute>Z2-p01</attribute>
</t>
the wanted, correct result is produced:
Processing Y
Processing X
Processing Y
Processing X
Do Note: Any attempt to use with a true XSLT 1.0 processor code like this (borrowed from another answer to this question) will fail with error:
<xsl:template match=
"attribute[
translate(.,
translate(.,
concat($upper, $lower),
''),
'')
and
translate(., translate(., $digit, ''), '')]
">
because in XSLT 1.0 it is forbidden for a match pattern to contain a variable reference.

Answer 2

If you found this question because you're looking for a way to use regular expressions in XSLT 1.0, and you're writing an application using Microsoft's XSLT processor, you can solve this problem by using an inline C# script.
I've written out an example and a few tips in this thread, where someone was seeking out similar functionality. It's super simple, though it may or may not be appropriate for your purposes.

Answer 3

XSLT does not support regular expressions, but you can fake it.
The following stylesheet prints an X processing message for all attribute elements having a string value containing at least one number and at least one letter (and Y processing for those that do not):
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:variable name="lower" select="'abcdefghijklmnopqrstuvwxyz'"/>
<xsl:variable name="upper" select="'ABCDEFGHIJKLMNOPQRSTUVWXYZ'"/>
<xsl:variable name="digit" select="'0123456789'"/>
<xsl:template match="attribute">
<xsl:choose>
<xsl:when test="
translate(., translate(., concat($upper, $lower), ''), '') and
translate(., translate(., $digit, ''), '')">
<xsl:message>X processing</xsl:message>
</xsl:when>
<xsl:otherwise>
<xsl:message>Y processing</xsl:message>
</xsl:otherwise>
</xsl:choose>
</xsl:template>
</xsl:stylesheet>
Note: You said this:
In example above, for case 1,2,4 I should be able to do X processing.
for case 3, I should be able to do Y processing.
But that conflicts with your requirement, because case 1 does not contain a letter. If, on the other hand, you really want to match the equivalent of [a-zA-Z0-9], then use this:
translate(., translate(., concat($upper, $lower, $digit), ''), '')
...which matches any attribute having at least one letter or number.
See the following question for more information on using translate in this way:
How to write xslt if element contains letters?