How to check contain only characters + space and `p` using regex - xslt

Question

I want to check to contain only characters + space and <p> nodes inside <used>.
Input:
<root>
<used><p>String 1</p></used>
<used>string 2<p>string 3</p></used>
<used>string 4</used>
<used><image>aaa.jpg</image>para</used>
The output should be:
<ans>
<abc>string 1</abc>
<abc>string 4</abc>
</ans>
Tried code:
<ans>
<abc>
<xsl:template match="root">
<xsl:choose>
<xsl: when test="getCode/matches(text(),'^[a-zA-Z0-9]+$')">
<xsl:text>text()</xsl:text>
</xsl:when>
</xsl:choose>
</xsl:template>
</abc>
</ans>
My tried code is not working as I am expecting. How can I fix this? Thank you. I am using XSLT 2.0

Answer 1

You can use the following XSLT-2.0 stylesheet to get the desired result:
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="2.0" xmlns:xsl= "http://www.w3.org/1999/XSL/Transform">
<xsl:output method="xml" indent="yes"/>
<!-- Handle the <root> element -->
<xsl:template match="/root">
<ans>
<xsl:apply-templates select="used" />
</ans>
</xsl:template>
<!-- Create <abc> elements for every matching element -->
<xsl:template match="used[not(*) and matches(text(),'^[\sa-zA-Z0-9]+$')] | used[not(text()) and matches(p/text(),'^[\sa-zA-Z0-9]+$')]/p">
<abc><xsl:copy-of select="text()" /></abc>
</xsl:template>
<!-- Remove all spurious text nodes -->
<xsl:template match="text()" />
</xsl:stylesheet>
Its result is
<?xml version="1.0" encoding="UTF-8"?>
<ans>
<abc>String 1</abc>
<abc>string 4</abc>
</ans>