How should I handle URLs inside XML?

Question

I'm creating an XML document and I want to store URLs inside the a node like so:

<ns:url>http://example.com&lt;/ns:ulr&gt;

My question is, do I need to encode/escape the URL in anyway?

If I do the will the .Net XmlDocument object handle this for me?

Answer 1

I doubt there will be any need to escape it in general. However, you might have some application level requirement to do so.

You should absolutely encode the URL as XML text (for example, it shouldn't contain >).

Clarification: This does not mean you should pass the encoded text to the DOM implementation. All XML APIs I know do that for you; so for all practical situations, you wouldn't need to do it manually. I just said it should be done.

Answer 2

In general most DOM implementations (including XmlDocument) should handle any necessary escaping of text content by default.

Answer 3

The DOM/XmlWriter/whatever you are using should handle that for you. One minor point: you might find it easier to use XDocument (if you have 3.5) - the namespace usage is much simpler (IMO):

XNamespace ns = "http://consoso/foobar";
XDocument doc = new XDocument(
     new XElement("Foo",
         new XAttribute(XNamespace.Xmlns + "ns", ns), // alias
         new XElement("Bar", "abc"),
         new XElement(ns + "url", "http://foo/bar")
     )
 );
 string s = doc.ToString();

Which creates:

<Foo xmlns:ns="http://consoso/foobar"&gt;
  <Bar>abc</Bar>
  <ns:url>http://foo/bar&lt;/ns:url&gt;
</Foo>