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Re: XPath namespace nodes

From: Gareth Reakes <gareth@decisionsoft.com>
Date: Tue, 17 Sep 2002 08:48:36 +0100 (BST)
To: Joseph Kesselman <keshlam@us.ibm.com>
cc: www-dom@w3.org
Message-ID: <Pine.LNX.4.44.0209170846360.1658-100000@somme.dsl.local>

Hi Joe,
	thanks for the reply. I followed your lead and made the 
ownerElement the the element that the ns attr was on. I then noticed a 
section 

http://www.w3.org/TR/2002/WD-query-datamodel-20020816/#NamespaceNode

which states that ns nodes have no parent. What is the use/need in setting 
the ownerElement if this is the case?

Gareth



On Fri, 13 Sep 2002, Joseph Kesselman wrote:

> 
> On Friday, 09/13/2002 at 10:25 MST, rayw@netscape.com (Ray Whitmer) wrote:
> > DOM Namespace nodes are clearly NOT created when the DOM element is
> > created.
> 
> They're created when the XPath runs, which I think is fine; anything 
> before that is "parse time" for XPath's purposes.
> 
> The only thing which might make this distinction visible would be that we 
> may produce new objects each time. HOWEVER -- remember that object 
> identity is *not* the official way to test DOM node identity; that can 
> only be done portably via the DOM L3  isSameNode() method. That could be 
> appropriate jiggered to return true for namespace node objects created via 
> two separate queries, if they declare the same prefix and namespace and if 
> the ownerElements match (also conceptually tested via isSameNode()).
> 
> 
> Note that in XPath 2.0 current draft the question of ownership of 
> namespace nodes pretty much goes away -- they allow it to be assigned 
> fairly arbitrarily, so it _could_ be the ownerElement of the actual Attr 
> this namespace came from.  (Xalan takes that approach and trusts XPath 2.0 
> will bless it. Fact is, almost nobody uses the namespace axis and of those 
> a vanishingly small number ever ask for the XPath-parent of a namespace 
> node, so this deliberate divergence from XPath 1.0 makes very little 
> real-world difference.)
> 
> ______________________________________
> Joe Kesselman  / IBM Research
> 
> 

-- 
Gareth Reakes, Head of Product Development  
DecisionSoft Ltd.            http://www.decisionsoft.com
Office: +44 (0) 1865 203192
Received on Tuesday, 17 September 2002 03:53:58 GMT

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