Trouble with inherent namespace XSLT - xslt

Question

I have trouble with namespace. I need this output:
<xyt:arguments xmlns:xyt="urn:xytechsystems.com/XytechAPI"
xmlns:NS1="http://schemahost.amcnetworks.com:8080/amcnesb/schemas">
but have trouble with add this namespace xmlns:xyt="urn:xytechsystems.com/XytechAPI" to the argument
I tried used xsl:namesapce, but think trouble in inherit with node
my xslt:
?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:amc="http://schemahost.amcnetworks.com:8080/amcnesb/schemas/adam"
xmlns:my="http://tempuri.org/dummy"
xmlns:i ="http://www.w3.org/2001/XMLSchema-instance"
xmlns:NS1="http://schemahost.amcnetworks.com:8080/amcnesb/schemas" exclude-result-prefixes="#all"
version="3.0">
<xsl:output method="xml" encoding="UTF-8" version="1.0" indent="yes"/>
<xsl:element name="soapenv:Envelope" >
<xsl:namespace name="i" select="'http://www.w3.org/2001/XMLSchema-instance'"/>
<xsl:namespace name="xyt1"
select="'http://schemas.datacontract.org/2004/07/Xytech.MP.API'"/>
<xsl:namespace name="xyt" select="'urn:xytechsystems.com/XytechAPI'"/>
<xsl:element name="soapenv:Header"/>
<xsl:element name="soapenv:Body"/>
<xsl:element name="xyt:Upsert">
<xsl:element name="xyt:credentials">
</xsl:element>
<xsl:element name="xyt:arguments">
<xsl:namespace name="xyt" select="urn:xytechsystems.com/XytechAPI">
<xsl:namespace name="NS1"
select="'http://schemahost.amcnetworks.com:8080/amcnesb/schemas'"/>
my output:
<soapenv:Envelope xmlns:i="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xyt1="http://schemas.datacontract.org/2004/07/Xytech.MP.API"
xmlns:xyt="urn:xytechsystems.com/XytechAPI"
xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
<soapenv:Header/>
<soapenv:Body/>
<xyt:Upsert>
<xyt:credentials/>
<xyt:arguments xmlns:NS1="http://schemahost.amcnetworks.com:8080/amcnesb/schemas">
<xsl:namespace name="xyt" select="'urn:xytechsystems.com/XytechAPI'"/>

Answer 1

You've tagged your question xslt-1.0, but xsl:namespace is an XSLT 2.0 instruction.
Given that you're creating elements whose names are known statically, it's easiest to do this using literal result elements. Change:
<xsl:element name="soapenv:Envelope" >
<xsl:namespace name="i" select="'http://www.w3.org/2001/XMLSchema-instance'"/>
<xsl:namespace name="xyt1"
select="'http://schemas.datacontract.org/2004/07/Xytech.MP.API'"/>
<xsl:namespace name="xyt" select="'urn:xytechsystems.com/XytechAPI'"/>
<xsl:element name="soapenv:Header"/>
<xsl:element name="soapenv:Body"/>
<xsl:element name="xyt:Upsert">
<xsl:element name="xyt:credentials">
</xsl:element>
to
<soapenv:Envelope
xmlns:i='http://www.w3.org/2001/XMLSchema-instance'
xmlns:xyt1='http://schemas.datacontract.org/2004/07/Xytech.MP.API'
xmlns:xyt='urn:xytechsystems.com/XytechAPI'>
<soapenv:Header/>
<soapenv:Body/>
<xyt:Upsert>
<xyt:credentials/>
Anyone who has to read your code will be eternally grateful to you.

Answer 2

If you want XSLT to output an element like e.g.
<xyt:arguments xmlns:xyt="urn:xytechsystems.com/XytechAPI"
xmlns:NS1="http://schemahost.amcnetworks.com:8080/amcnesb/schemas">
</xyt:arguments>
then the easiest way and the straight-forwards one is to write it as a literal result element i.e.
<xyt:arguments xmlns:xyt="urn:xytechsystems.com/XytechAPI"
xmlns:NS1="http://schemahost.amcnetworks.com:8080/amcnesb/schemas">
</xyt:arguments>
All use of xsl:element is only needed if you want to compute the name and/or namespace (or at least parts of them) during the execution of the XSLT, based on some input data.

Answer 3

I'm agreeing with #mads-hansen's comment:
The namespace URI is already declared with prefix xyt in an ancestor element hence will not be re-declared in the child element for the same prefix. (That's the namespace-fixup mechanism in XSLT.)
You can change the parent prefixes to be xyt1 so that the xyt prefix is new in the xyt:arguments element, even though it is the same namespace URI.
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:NS1="http://schemahost.amcnetworks.com:8080/amcnesb/schemas"
xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"
xmlns:xyt1="urn:xytechsystems.com/XytechAPI"
exclude-result-prefixes="#all"
version="3.0">
<xsl:output method="xml" encoding="UTF-8" version="1.0" indent="yes"/>
<xsl:template name="xsl:initial-template">
<xsl:element name="soapenv:Envelope" >
<xsl:element name="soapenv:Header"/>
<xsl:element name="soapenv:Body"/>
<xsl:element name="xyt1:Upsert">
<xsl:element name="xyt1:credentials" />
<xsl:element name="xyt:arguments" namespace="urn:xytechsystems.com/XytechAPI">
<xsl:namespace name="NS1" select="'http://schemahost.amcnetworks.com:8080/amcnesb/schemas'"/>
</xsl:element>
</xsl:element>
</xsl:element>
</xsl:template>
</xsl:stylesheet>
gives
<?xml version="1.0" encoding="UTF-8"?>
<soapenv:Envelope xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xyt1="http://schemas.datacontract.org/2004/07/Xytech.MP.API">
<soapenv:Header/>
<soapenv:Body/>
<xyt1:Upsert xmlns:xyt1="urn:xytechsystems.com/XytechAPI">
<xyt1:credentials/>
<xyt:arguments xmlns:NS1="http://schemahost.amcnetworks.com:8080/amcnesb/schemas" xmlns:xyt="urn:xytechsystems.com/XytechAPI"/>
</xyt1:Upsert>
</soapenv:Envelope>
but I don't see why that is preferable to using the same xyt prefix everywhere in the document.