XPath error: Cannot select a node here: the context item is an atomic value
Assume the input xml file is like
<people>
<person>
<name>paul</name>
<gender>male</gender>
</person>
<person>
<name>lee</name>
<gender>female</gender>
</person>
</people>
This XPath error complained for the below style sheet.
<?xml version="1.0"?>
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="/">
<xsl:element name="team">
<xsl:for-each select="distinct-values(//gender)">
<xsl:variable name="gender" select="."/>
<xsl:element name="{$gender}">
<xsl:for-each select="//person[gender=$gender]"> <!-- Wrong! A node is selected for actomic context item. -->
<xsl:variable name="name" select="name"/>
<xsl:element name="{$name}"/>
</xsl:for-each>
</xsl:element>
</xsl:for-each>
</xsl:element>
</xsl:template>
</xsl:stylesheet>
This error means that a node was selected for a actomic context item. The atomic context item is chosen by the outer for-each loop <xsl:for-each select="distinct-values(//gender)"/>.
Node items can not be selected in this loop context.
The solution is define a variable outside of loop. the variable value is the string of the node path. Then select the node with that variable.
<?xml version="1.0"?>
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="/">
<xsl:element name="team">
<xsl:variable name="person" select="//person"/> <!-- Define the variable with the node path. -->
<xsl:for-each select="distinct-values(//gender)">
<xsl:variable name="gender" select="."/>
<xsl:element name="{$gender}">
<xsl:for-each select="$person[gender=$gender]"> <!-- Select the node by the variable defined outside of this for-each loop. -->
<xsl:variable name="name" select="name"/>
<xsl:element name="{$name}"/>
</xsl:for-each>
</xsl:element>
</xsl:for-each>
</xsl:element>
</xsl:template>
</xsl:stylesheet>
Weird enough, but seems like the only available solution.