More than one namespace declaration in an element

[Gustaf Liljegren]

I'm using XmlTextWriter to generate an XML document. I can't figure
out how to get more than one namespace declaration in an element, when
there is no WriteNamespaceDeclaration() method.

Thanks,

Gustaf

[Gustaf Liljegren]

"Gustaf Liljegren" <gu**************@bredband.net> wrote:

I'm using XmlTextWriter to generate an XML document. I can't figure
out how to get more than one namespace declaration in an element, when there is no WriteNamespaceDeclaration() method.

I found a solution to this, by just adding an attribute:

w.WriteAttributeString("xmlns:int", NS_INT);

But there's still a problem. The elements below this element doesn't
recognize the attributes, so the namespace declarations are repated
for each element. Is there a solution for this too?

Gustaf

[Oleg Tkachenko [MVP]]

Gustaf Liljegren wrote:

I'm using XmlTextWriter to generate an XML document. I can't figure
out how to get more than one namespace declaration in an element, when
there is no WriteNamespaceDeclaration() method.

What for? Namespace declarations are generated automatically on demand
(if you write element or attribute, which is in non-declared yet namespace).
--
Oleg Tkachenko [XML MVP, XmlInsider]
http://blog.tkachenko.com

[Oleg Tkachenko [MVP]]

Gustaf Liljegren wrote:

But there's still a problem. The elements below this element doesn't
recognize the attributes, so the namespace declarations are repated
for each element. Is there a solution for this too?

Most likely you are doing something wrong. You are not supposed to
create namespace declarations by hands, that's XmlWriter's responsibility.
--
Oleg Tkachenko [XML MVP, XmlInsider]
http://blog.tkachenko.com

[Marco A. Sánchez]

To write namespace declarations in an element you must use one of the WriteAttribute* methods. Take into account that a namespace declaration is sintactically a form of an attribute. For example, to write out the namespace declarations of the following XML element

<someElement xmlns="http://an-url" xmlns:a="http://another-url"><!--Element content--></someElement

You can use

writer.WriteAttributeString("xmlns", null, "http://an-url"
writer.WriteAttributeString("xmlns", "a", null, "http://another-url"

[Gustaf Liljegren]

"Oleg Tkachenko [MVP]" <oleg@NO!SPAM!PLEASEtkachenko.com> wrote:

But there's still a problem. The elements below this element doesn't recognize the attributes, so the namespace declarations are repated for each element. Is there a solution for this too?

Most likely you are doing something wrong. You are not supposed to
create namespace declarations by hands, that's XmlWriter's

responsibility.

Thank you both. What complicates my problem is that I need to import a
chunk of XML from an existing document, into a document that I
generate dynamically. Here's the code for extracting the chunk:

XmlDocument d = new XmlDocument();
d.Load(file_document);
XmlNodeList nl =
d.DocumentElement.GetElementsByTagName("GeneralDoc umentInformation",
NS_XBRL);

And here is the document that is being generated:

// Create XmlTextWriter
XmlTextWriter w = new XmlTextWriter("output.xml",
System.Text.Encoding.UTF8);
w.Formatting = Formatting.Indented;
w.Indentation = 2;
w.WriteStartDocument();
w.WriteStartElement("xbrl", NS_XBRL);
w.WriteAttributeString("xmlns:int", NS_INT);
w.WriteAttributeString("xmlns:bas", NS_BAS);
w.WriteRaw(nl.Item(0).OuterXml);

The chunk that is imported looks like this:

<GeneralDocumentInformation>
<int:DocumentLastEditDate>1995-09-25</int:DocumentLastEditDate>
<int:EntityCurrentLegalNameName />
<int:EntityIdentifier>

<int:EntityIdentifierDescription>50020</int:EntityIdentifierDescriptio
n>
</int:EntityIdentifier>
<int:EntityTradingName />
<bas:LocalAddress>
<int:Street1>Gångstigen 4</int:Street1>
</bas:LocalAddress>
<bas:ZIPPostalCode>414 65</bas:ZIPPostalCode>
<int:City>GÖTEBORG</int:City>
<bas:PhoneFaxNumbers>
<bas:Phone />
</bas:PhoneFaxNumbers>
</GeneralDocumentInformation>

And this is the result I get (removed the URIs for readability):

<?xml version="1.0" encoding="utf-8"?>
<xbrl xmlns:int="..." xmlns:bas="..." xmlns="...">
<GeneralDocumentInformation xmlns="...">
<int:DocumentLastEditDate xmlns:int="...">
1995-09-25
</int:DocumentLastEditDate>
<int:EntityCurrentLegalNameName xmlns:int="..." />
<int:EntityIdentifier xmlns:int="...">
<int:EntityIdentifierDescription>
50020
</int:EntityIdentifierDescription>
</int:EntityIdentifier>
<int:EntityTradingName xmlns:int="..." />
<bas:LocalAddress xmlns:bas="...">
<int:Street1 xmlns:int="...">Gångstigen 4</int:Street1>
</bas:LocalAddress>
<bas:ZIPPostalCode xmlns:bas="...">414 65</bas:ZIPPostalCode>
<int:City xmlns:int="...">GÖTEBORG</int:City>
<bas:PhoneFaxNumbers xmlns:bas="...">
<bas:Phone />
</bas:PhoneFaxNumbers>
</GeneralDocumentInformation>
</xbrl>

Thanks a lot for help.

Gustaf

[Gustaf Liljegren]

"Marco A. Sánchez" <an*******@discussions.microsoft.com> wrote:

writer.WriteAttributeString("xmlns", null, "http://an-url")
writer.WriteAttributeString("xmlns", "a", null,

"http://another-url")

If found this way is a little shorter:

writer.WriteAttributeString("xmlns", "http://an-url")
writer.WriteAttributeString("xmlns:a", "http://another-url")

Both gives me exactly the same result.

Gustaf

[Marco A. Sánchez]

The problem with

writer.WriteAttributeString("xmlns:a", "http://another-url")

is that the first parameter must be a local name, not a QName. Doing the previous call, the XML writer doesn't known that "a" is a namespace prefix, so it doesn't put the namespace declaration into the writer's namespace stack. Although the output XML is identicall, the method call is wrong, so you can't use the "a" prefix in subsequent calls.

[Gustaf Liljegren]

I made an example to play with. Hope someone can help me getting it
right:

using System;
using System.Xml;

class XmlTest
{
private const string NS1 = "http://www.ns1.org";
private const string NS2 = "http://www.ns2.org";

static void Main(string[] args)
{
// Start document
XmlTextWriter w = new XmlTextWriter("output.xml",
System.Text.Encoding.UTF8);
w.WriteStartDocument();
w.WriteStartElement("root");
w.WriteAttributeString("xmlns", NS1);
w.WriteAttributeString("xmlns:ns2", NS2);

// Add chunk of XML from existing document
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load("input.xml");
XmlNodeList xmlNodes = xmlDoc.GetElementsByTagName("chunk");
string chunk = xmlNodes.Item(0).OuterXml;
w.WriteRaw(chunk);

// End document
w.WriteEndElement();
w.WriteEndDocument();
w.Close();
}
}

The "input.xml" document looks like this:

<?xml version="1.0"?>
<document xmlns="http://ns1.org" xmlns:ns2="http://ns2.org">
<chunk>
<ns2:text>Some text here.</ns2:text>
</chunk>
</document>

The output I get looks liks this:

<?xml version="1.0" encoding="utf-8"?>
<root xmlns="http://www.ns1.org" xmlns:ns2="http://www.ns2.org">
<chunk xmlns="http://ns1.org">
<ns2:text xmlns:ns2="http://ns2.org">Some text here.</ns2:text>
</chunk>
</root>

And the output I want looks like this:

<?xml version="1.0" encoding="utf-8"?>
<root xmlns="http://www.ns1.org" xmlns:ns2="http://www.ns2.org">
<chunk>
<ns2:text>Some text here.</ns2:text>
</chunk>
</root>