creating xslt 1.0 to group element - xslt

Question

Could you please help me with grouping in xslt .
Input.xml :
<EDI>
<Header/>
<Data>
<ISA> <Identifier>123</Identifier>
</ISA>
<Function>
<Transaction>
<BPR><Account> 123<Account></BPR>
<CUR><Code>USD</Code></CUR>
</Transaction>
<Transaction>
<BPR><Account> 123<Account></BPR>
<CUR><Code>EUR</Code></CUR>
</Transaction>
<Transaction>
<BPR><Account> 123<Account></BPR>
<CUR><Code>USD</Code></CUR>
</Transaction>
</Function>
</Data>
</EDI>
I want to group the input xml based on CUR/Code . I have created key and generateid also but the in my output xml it reflecting ISA field value also before Output.
Output xml :
<Output>
<Filename>USAFile</Filename> (If the current-group has Code USD)
<EDI>
<Data><ISA><Identifier>12</Identifier></ISA>
<Function>
<Transaction>
<BPR><Account> 123<Account></BPR>
<CUR><Code>USD</Code></CUR>
</Transaction>
<Transaction>
<BPR><Account> 123<Account></BPR>
<CUR><Code>USD</Code></CUR>
</Transaction>
</Function>
</Data>
</EDI>
</Output>
<Output>
<Filename>EURFile</Filename> (If the current-group has Code EUR)
<EDI>
<Data><ISA><Identifier>23</Identifier></ISA>
<Function>
<Transaction>
<BPR><Account> 123<Account></BPR>
<CUR><Code>EUR/Code></CUR>
</Transaction>
</Data>
</EDI>
</Output>
XSLT :
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:tib="http://www.tibco.com/bw/xslt/custom-functions" version="1.0">
<xsl:output method="xml" omit-xml-declaration="yes" version="1.0" encoding="UTF-8" indent="no"/>
<xsl:key name="groups" match="/EDI/Data/Function/Transaction" use="CUR/Code" />
<xsl:template match="Function">
<Function>
<xsl:for-each select="Transaction[generate-id() = generate-id(key('groups', CUR/Code)[1])]"/>
<xsl:for-each select="key('groups',CUR/Code)">
<Transaction>
<BR><Account><xsl:value-of select="BPR/Account"/></Account>
<CUR><Code><xsl:value-of select="CUR/Code"/></Code>
</Transaction>
</xsl:for-each>
</xsl:for-each>
</Function>
</xsl:template>
</xsl:stylesheet>

Answer 1

Firstly making your input XML well formed as below:
<?xml version="1.0" encoding="UTF-8"?>
<EDI>
<Header />
<Data>
<ISA>
<Identifier>123</Identifier>
</ISA>
<Function>
<Transaction>
<BPR>
<Account>
123
</Account>
</BPR>
<CUR>
<Code>USD</Code>
</CUR>
</Transaction>
<Transaction>
<BPR>
<Account>
123
</Account>
</BPR>
<CUR>
<Code>EUR</Code>
</CUR>
</Transaction>
<Transaction>
<BPR>
<Account>
123
</Account>
</BPR>
<CUR>
<Code>USD</Code>
</CUR>
</Transaction>
</Function>
</Data>
</EDI>
Using a bit different approach than what you tried (in case if it is okay with your case):
Note: In your output XML, you have shown two different values for <Identifier> in <ISA>. I guessed it as typo. Correct me if I am missing something.
<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
<xsl:output method="xml" indent="yes" />
<xsl:strip-space elements="*" />
<xsl:key name="groups" match="/EDI/Data/Function/Transaction" use="CUR/Code" />
<xsl:template match="Function">
<xsl:apply-templates mode="group" />
</xsl:template>
<xsl:template match="Transaction[count(. | key('groups',CUR/Code)[1]) = 1]" mode="group">
<Output>
<Filename>
<xsl:choose>
<xsl:when test="CUR/Code = 'USD'">
<xsl:value-of select="'USAFile'" />
</xsl:when>
<xsl:when test="CUR/Code = 'EUR'">
<xsl:value-of select="'EURFile'" />
</xsl:when>
</xsl:choose>
</Filename>
<EDI>
<Data>
<ISA>
<Identifier>
<xsl:value-of select="../preceding-sibling::*[1]" />
</Identifier>
</ISA>
<Function>
<Transaction>
<xsl:copy-of select="key('groups',CUR/Code)" />
</Transaction>
</Function>
</Data>
</EDI>
</Output>
</xsl:template>
<xsl:template match="ISA" />
<!-- remove nodes other than through the key -->
<xsl:template match="node()" mode="group" />
</xsl:stylesheet>
https://xsltfiddle.liberty-development.net/94rmq63