How do I use the msxsl:node-set to get a node set that I can use in a template parameter? - xpath

Question

TL;DR; Why can't I use the element name in the XPATH going against a msxsl:node-set? It always returns nothing, as if the node-set is empty, when debugging shows that it is not empty.
Details: I need to use a node-set in an XSLT 1.0 document because my source XML is missing an important node. Instead of having to rewrite the entire XSLT, I'd like to instead inject a node-set so that my XSLT processing can continue as normal. I would like to use XPATH on the node-set but I am not able to use the actual element names, instead only a * works, but I am not sure why, or how I can access the actual element names in the XPATH.
Here is my XML (example only, the XML document here is the least important, see XSLT):
<?xml version="1.0" encoding="utf-8" ?>
<?xml-stylesheet type="text/xsl" href="generic.xslt" ?>
<ParentNode xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" i:noNamespaceSchemaLocation="generic.xsd">
<SomeChildNode>text</SomeChildNode>
</ParentNode>
Here is my XSLT:
<?xml version="1.0" encoding="utf-16"?>
<xsl:stylesheet version="1.0" xmlns="http://schemas.datacontract.org/2004/07/MeM.BizEntities.Integration.DataFeedV2" xmlns:msxsl="urn:schemas-microsoft-com:xslt" xmlns:a="http://schemas.datacontract.org/2004/07/MeM.BizEntities" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
<xsl:output method="xml" indent="yes" encoding="utf-16" omit-xml-declaration="no" />
<!-- Global Variables, used in multiple places -->
<xsl:variable name="empty"/>
<!-- Match Templates -->
<xsl:template match="ParentNode">
<ArrayOfSalesOrder>
<xsl:for-each select="SomeChildNode">
<xsl:call-template name="SomeChildNodeTemplate">
<xsl:with-param name="order" select="."/>
</xsl:call-template>
</xsl:for-each>
</ArrayOfSalesOrder>
</xsl:template>
<xsl:template name="SomeChildNodeTemplate">
<xsl:variable name="someRTF">
<Items>
<Item>
<Code>code</Code>
<Price>75</Price>
<Quantity>1</Quantity>
</Item>
<Item>
<Code>code2</Code>
<Price>100</Price>
<Quantity>3</Quantity>
</Item>
</Items>
</xsl:variable>
<xsl:call-template name="ItemsTemplate">
<xsl:with-param name="items" select="msxsl:node-set($someRTF)"/>
</xsl:call-template>
</xsl:template>
<xsl:template name="ItemsTemplate">
<xsl:param name="items"/>
<ItemsTransformed>
<xsl:for-each select="$items/Item">
<NewItem>
<NewCode>
<xsl:value-of select="Code"/>
</NewCode>
</NewItem>
</xsl:for-each>
</ItemsTransformed>
<ItemsTransformedThatWorksButNotHowIWant>
<xsl:for-each select="$items/*/*">
<NewItem>
<NewCode>
<xsl:value-of select="*[1]"/>
</NewCode>
<NewPrice>
<xsl:value-of select="*[2]"/>
</NewPrice>
<NewQuantity>
<xsl:value-of select="*[3]"/>
</NewQuantity>
</NewItem>
</xsl:for-each>
</ItemsTransformedThatWorksButNotHowIWant>
</xsl:template>
</xsl:stylesheet>
I would expect to be able to use XPATH to query into the node-set such that I can use their proper element names. This doesn't seem to be the case, and I'm struggling to understand why. I know there can be namespacing issues, but trying *:Item etc. doesn't work for me. I am able to use *[local-name()='Item'] but this seems like a horrible work around, not to mention that I'll have to rewrite any downstream templates and that is what I'm trying to avoid by using the node-set in the first place.
Result:
<?xml version="1.0" encoding="utf-16"?>
<ArrayOfSalesOrder xmlns="http://schemas.datacontract.org/2004/07/MeM.BizEntities.Integration.DataFeedV2" xmlns:msxsl="urn:schemas-microsoft-com:xslt" xmlns:a="http://schemas.datacontract.org/2004/07/MeM.BizEntities" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
<ItemsTransformed />
<ItemsTransformedThatWorksButNotHowIWant>
<NewItem>
<NewCode>code</NewCode>
<NewPrice>75</NewPrice>
<NewQuantity>1</NewQuantity>
</NewItem>
<NewItem>
<NewCode>code2</NewCode>
<NewPrice>100</NewPrice>
<NewQuantity>3</NewQuantity>
</NewItem>
</ItemsTransformedThatWorksButNotHowIWant>
</ArrayOfSalesOrder>
As you can see, I can get it to work with * but this is not very usable on a more complex structure. What am I doing wrong? Does this have to do with namespaces?
I would expect to see something under the <ItemsTransformed /> node, but instead it is just empty, and so far I can't get anything except the * to work.
The SO question below is what I was using, I thought I had an answer there, but I can't get the XPATH to work.
Reference:
XSLT 1.0 - Create node set and pass as a parameter

Answer 1

The problem here is that your stylesheet has a default namespace:
xmlns="http://schemas.datacontract.org/2004/07/MeM.BizEntities.Integration.DataFeedV2"
Therefore, when you do:
<xsl:variable name="someRTF">
<Items>
<Item>
<Code>code</Code>
<Price>75</Price>
<Quantity>1</Quantity>
</Item>
<Item>
<Code>code2</Code>
<Price>100</Price>
<Quantity>3</Quantity>
</Item>
</Items>
</xsl:variable>
you are populating your variable with elements in the default namespace, so the variable actually contains:
<Items xmlns="http://schemas.datacontract.org/2004/07/MeM.BizEntities.Integration.DataFeedV2">
<Item>
<Code>code</Code>
<Price>75</Price>
<Quantity>1</Quantity>
</Item>
<Item>
<Code>code2</Code>
<Price>100</Price>
<Quantity>3</Quantity>
</Item>
</Items>
Naturally, when you try later to select something like:
<xsl:for-each select="xyz:node-set($someRTF)/Items/Item">
you select nothing, because both Items and Item are in the default namespace and you're not calling them by their fully qualified name.
--- edit: ---
The problem can be easily solved by making sure that the root element of the variable - and by extension, all its descendants - are in no namespace.
Here's a simplified example (will run with any input):
XSLT 1.0
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns="http://schemas.datacontract.org/2004/07/MeM.BizEntities.Integration.DataFeedV2"
xmlns:exsl="http://exslt.org/common"
exclude-result-prefixes="exsl">
<xsl:output method="xml" version="1.0" encoding="UTF-8" indent="yes"/>
<xsl:variable name="someRTF">
<Items xmlns="">
<Item>
<Code>code</Code>
<Price>75</Price>
<Quantity>1</Quantity>
</Item>
<Item>
<Code>code2</Code>
<Price>100</Price>
<Quantity>3</Quantity>
</Item>
</Items>
</xsl:variable>
<xsl:template match="/">
<ArrayOfSalesOrder>
<ItemsTransformed>
<xsl:for-each select="exsl:node-set($someRTF)/Items/Item">
<NewItem>
<NewCode>
<xsl:value-of select="Code"/>
</NewCode>
</NewItem>
</xsl:for-each>
</ItemsTransformed>
</ArrayOfSalesOrder>
</xsl:template>
</xsl:stylesheet>
Result:
<?xml version="1.0" encoding="UTF-8"?>
<ArrayOfSalesOrder xmlns="http://schemas.datacontract.org/2004/07/MeM.BizEntities.Integration.DataFeedV2">
<ItemsTransformed>
<NewItem>
<NewCode>code</NewCode>
</NewItem>
<NewItem>
<NewCode>code2</NewCode>
</NewItem>
</ItemsTransformed>
</ArrayOfSalesOrder>