Fw: Node.namespaceURI

[Scott Nichol <sn...@scottnichol.com>]

All,

Some time ago, there was a question asked about Apache SOAP and the Oracle XML parser's DOM implementation.  Apache SOAP following its interpretation of the DOM spec, in that a node without a namespace would have a value of null for the namespaceURI property.  Oracle, as Microsoft has chosen to do with .NET, instead returns an empty string when there is no namespace.

Rather than simply change the Apache SOAP code, I sent an e-mail to the W3C DOM working group, asking them to change the DOM 3 spec, which is in progress, to clarify the issue, e.g. to specify whether or not an empty string is not an appropriate return value.

Below is the first reply from a committee member.  It is not a direct clarification of what should be returned for the namespaceURI property, but it does change from "implementation dependent" the guidelines for how to handle an empty string passed as a namespaceURI to other methods in the API, namely that the implementation should convert it to null.

Even without clarification from W3C, I continue to hope that Oracle will change its implementation.

Scott Nichol

----- Original Message ----- 
From: "Philippe Le Hegaret" <pl...@w3.org>
To: "Scott Nichol" <sc...@comcast.net>
Cc: "WWW DOM" <ww...@w3.org>
Sent: Thursday, August 28, 2003 1:16 PM
Subject: Re: Node.namespaceURI


On Fri, 2003-07-25 at 11:20, Scott Nichol wrote:
> 
> 
> This regards Node.namespaceURI in the DOM 3 Core.  Going back to DOM 2, this attribute's description has started "The namespace URI of this node, or null if it is unspecified".  To me, this seems quite clear, and in programming languages like Java, I expect a null value in that language to be returned.
> 
> However, there are implementations that do not use what I would consider to be a null.  For example, Oracle's XML parser's Node.getNamespaceURI() returns an empty (zero-length) string, and Microsoft's .NET framework (the NamespaceURI property of the System.Xml.XmlNode class) likewise returns an empty string.
> 
> I would like to see DOM 3 Core clarify or amend the statement "The namespace URI of this node, or null if it is unspecified".  If implementations returning empty strings are to be considered out-of-spec, please specify this explicitly.  If returning a zero-length string is an acceptible implementation according to the standard, please state this.  If this issue is clarified elsewhere in the DOM 3 spec, please refer to that place from the description of Node.namespaceURI.

We clarified the XML Namespaces section and replace the sentence in the
3rd paragraph with the following one:
[[
In programming languages where empty strings can be differentiated from
null, empty strings, when given as a namespace URI, are converted to
<code>null</code>.
]]

A link has been added from Node.namespaceURI to the XML namespaces
section.

Philippe