CODEWITHSUNDEEP
c#xmlxml-parsingxml-namespacesprefix
Acewave
Acewave

Reputation: 23

How can I replace xmlns namespace attributes with prefixes?

I have been trying to write a utility in C# which takes an XML file, removes the xmlns attributes from the tags, sets the prefix of these attributes in the root tag, and then uses these prefixes in the tags instead.

Source XML file:

<?xml version="1.0" encoding="utf-8"?>
<Main version="1.0" xmlns="urn:root:v1">
    <Report>
        <Title>Some Value</Title>
    </Report>
    <Content>
        <Address>
            <CountryName xmlns="urn:location:v2">Australia</CountryName>
        </Address>
    </Content>
</Main>

Target XML file:

<?xml version="1.0" encoding="utf-8"?>
<root:Main version="1.0" xmlns:root="urn:root:v1" xmlns:loc="urn:location:v2">
    <root:Report>
        <root:Title>Some Value</root:Title>
    </root:Report>
    <root:Content>
        <root:Address>
            <loc:CountryName>Australia</loc:CountryName>
        </root:Address>
    </root:Content>
</root:Main>

I've managed to get part of the way there with the following code. I have replaced all tags with no attributes with the root prefix, and added the xmlns attribute to the root tag, but have not been successful with removing the xmlns attribute from CountryName tag and using the prefix there instead.

XDocument doc = XDocument.Load(@"C:\Temp\Source.xml");

var content = XElement.Parse(doc.ToString());

content.Attributes("xmlns").Remove();

content.Add(new XAttribute(XNamespace.Xmlns + "root", "urn:root:v1"));
content.Add(new XAttribute(XNamespace.Xmlns + "loc", "urn:location:v2"));

foreach (var node in doc.Root.Descendants().Where(n => n.Name.NamespaceName == "urn:location:v2"))
{
    node.Attribute("xmlns").Remove();
    node.Add(new XAttribute(XNamespace.Xmlns + "loc", "urn:location:v2"));
}   

content.Save(@"C:\Temp\Target.xml");

Any help would be appreciated - thanks!

Upvotes: 2

Views: 4729

Answers (2)

Charles Mager
Charles Mager

Reputation: 26213

You're not a million miles away. All you need to do is remove any existing namespace declaration attributes and then add the ones you want to the root. The rest will be taken care of.

var doc = XDocument.Load(@"C:\Temp\Source.xml");

doc.Descendants().Attributes().Where(x => x.IsNamespaceDeclaration).Remove();
doc.Root.Add(new XAttribute(XNamespace.Xmlns + "root", "urn:root:v1"));
doc.Root.Add(new XAttribute(XNamespace.Xmlns + "loc", "urn:location:v2"));

doc.Save(@"C:\Temp\Target.xml");

See this fiddle for a demo.

Upvotes: 1

Parfait
Parfait

Reputation: 107587

Consider XSLT, the special-purpose language designed to transform XML files. While I personally do not know or use C#, I do know it can run XSLT 1.0 scripts. See answers here. Also, the XSLT processor you choose to use must allow the document() function for this solution.

XSLT (save as .xsl file; notice namespaces declared in header)

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                              xmlns:root="urn:root:v1" xmlns:local="urn:location:v2">
    <xsl:output omit-xml-declaration="no" indent="yes"/>
    <xsl:strip-space elements="*"/>

    <xsl:template match="node()|@*">
       <xsl:copy>
         <xsl:apply-templates select="node()|@*"/>
       </xsl:copy>
    </xsl:template>

    <xsl:template match="*">
      <xsl:element name="root:{name()}" namespace="urn:root:v1">
         <xsl:copy-of select="document('')/*/namespace::local"/>
         <xsl:apply-templates select="node()|@*"/>
      </xsl:element>
    </xsl:template>    

    <xsl:template match="*[local-name()='CountryName']">
      <xsl:element name="local:{name()}" namespace="urn:location:v2">
         <xsl:apply-templates select="node()|@*"/>
      </xsl:element>
    </xsl:template>

</xsl:stylesheet>

C# (see link above)

var myXslTrans = new XslCompiledTransform(); 

myXslTrans.Load("XSLTScript.xsl"); 
myXslTrans.Transform("Input.xml", "Output.xml");

XML Output

<?xml version="1.0"?>
<root:Main xmlns:root="urn:root:v1" xmlns:local="urn:location:v2" version="1.0">
  <root:Report>
    <root:Title>Some Value</root:Title>
  </root:Report>
  <root:Content>
    <root:Address>
      <local:CountryName>Australia</local:CountryName>
    </root:Address>
  </root:Content>
</root:Main>

Upvotes: 1

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