OASIS Mailing List ArchivesView the OASIS mailing list archive below
or browse/search using MarkMail.


Help: OASIS Mailing Lists Help | MarkMail Help



   Re: [xml-dev] Question for the XPath and DOM folks

[ Lists Home | Date Index | Thread Index ]

> Read Garland Foster's response if you still don't understand the question. 

By this, do you mean the response you forwarded to the list?  Because his 
latest response (which i in turn responded to) seems to be in line with what 
I've been saying.

OK, just in case, I'll gander over the earlier message:


"If it returns a nodeset containing one text node should be returned then 
where does it come from and what is the node's parent?"

It comes from wherever the implementation makes it.  I don't think there is 
any answer to this question outside implementation specifics.  If by what is 
the node's parent, you mean what is the answer to

"/foo/text()[1]/parent::*", then clearly the answer is the <foo/> element.


"In the DOM the <foo> element has 3 children; 2 text nodes and 1 CDATA node. 
Your suggestion implies that the XPath query creates a new DOM node."

No it doesn't.  As an example of another possibility, the XPath implementation 
could serialize the document into a special XPath-compliant object model.  DOM 
needn't come into it.

Again, though, no answer to this outside implemnetation specifics.


"Suppose we do create the new node. What happen when we query its parent? If 
the parent is <foo>, what happens when we ask it for its children do we get 
our original 3 or the newly created text node?"

If by this question, you mean "what is the result of 

Then the answer is a node set with one text node.
I think I understand what you are getting at, but I am serious when I say you 
cannot expect "right" answers here.  The question of how an implementation 
shoud interpret output from XPath, regardless of what its input might have 
been, is not covered by any spec.

I don't think the DOM WG will have any universally satisfactory way to answer 
this question, either.  If I were on the WG, I would suggest that an XPath 
query on a DOM node should be considered a potential mutation operation, and 
that the text nodes should be normalized in the process.

But who am I?  :-)

Uche Ogbuji                                    Fourthought, Inc.
http://uche.ogbuji.net    http://4Suite.org    http://fourthought.com
Track chair, XML/Web Services One Boston: http://www.xmlconference.com/
The many heads of XML modeling - http://adtmag.com/article.asp?id=6393
Will XML live up to its promise? - http://www-106.ibm.com/developerworks/xml/li


News | XML in Industry | Calendar | XML Registry
Marketplace | Resources | MyXML.org | Sponsors | Privacy Statement

Copyright 2001 XML.org. This site is hosted by OASIS