How to remove a space in XML using stylesheet using RegEx - regex

Question

I have an XML and I am looking for finding particular tag (in this case "FirstName") and removing space in the value only if there is a - character before the space.
In other words, I want to keep spaces if there is no - front of them. I want to do this using an XSL stylesheet with RegEx matching and replace function.
Expected result is Sam-Louise, removing space between "Sam-" and "Louise"
<?xml version="1.0" encoding="utf-8"?>
<NCV Version="1.14">
<Invoice>
<customer>
<customerId>12785</customerId>
<FirstName>Sam- Louise</FirstName>
<LastName>Jones</LastName>
</customer>
</Invoice>
</NCV>

Answer 1

This is one possible XSLT :
<xsl:transform xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="2.0">
<xsl:output method="html" encoding="UTF-8" indent="yes" />
<xsl:strip-space elements="*"/>
<xsl:template match="FirstName">
<FirstName>
<xsl:value-of select="replace(., '-\s+', '-')"/>
</FirstName>
</xsl:template>
<xsl:template match="#*|node()">
<xsl:copy>
<xsl:apply-templates select="#*|node()"/>
</xsl:copy>
</xsl:template>
</xsl:transform>
xsltransform.net demo
output :
<NCV Version="1.14">
<Invoice>
<customer>
<customerId>12785</customerId>
<FirstName>Sam-Louise</FirstName>
<LastName>Jones</LastName>
</customer>
</Invoice>
</NCV>

Answer 2

You can use following RegEx in match
(\<FirstName\>.*?-)\s+
And replace it with the first captured group $1
RegEx (\<FirstName\>.*?-)\s+ matches,
\<FirstName\>.*?-: Literal <FirstName> followed by any character non-greedy, until first hyphen is found. This match is added in the captured group.
\s+: Match one or more of the space characters.
By replacing it with $1, will remove the spaces after hyphen.