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RE: New XPath Filter Transform

From: Joseph Reagle <reagle@w3.org>
Date: Tue, 19 Mar 2002 16:36:41 -0500
Message-Id: <200203192136.QAA00876@tux.w3.org>
To: JBoyer@PureEdge.com
Cc: "merlin" <merlin@baltimore.ie>, "TAMURA Kent" <kent@trl.ibm.co.jp>, <w3c-ietf-xmldsig@w3.org>

If we seperate out the issue of what sort of operation occurs (interset, 
substract, include-search-forward, etc.) and focus on the input, I'm still 
a little confused. Folks seems to have passed me by and agreed that the 
input nodeset is that of the *original* document.

John said:
  Please see the first paragraph of Section 3.3 "Input and
  Evaluation Context of Signature Filter Transform":
  "...The XPath evaluation context for the node-set will be:
  A context node equal to the root node of the document whose
  node-set was provided as input to this transform..."
  http://lists.w3.org/Archives/Public/w3c-ietf-xmldsig/2002JanMar/0196.html

Yes, and the input is the nodeset resulting from the previous step 
(dereferencing and parsing a URI, or the output of the previous transform). 
If the previous transform was a similar XPath transform, then that input 
from the previous step would be the:

  An inclusive filter is a signature filter transform whose output
  node-set contains only those nodes in the subtrees identified
  by a given XPath expression.
  An exclusive filter is a signature filter transform whose output
  node-set contains all nodes of a document except those nodes
  in the subtrees identified by a given XPath expression. 
 http://www.w3.org/Signature/Drafts/xmldsig-xpath/Overview.html#sec-Terminol
ogy

And consequently, if there was a "chain" of them, I'd expect what Gregor 
demonstrated [1]. What did I miss?

[1] 
http://lists.w3.org/Archives/Public/w3c-ietf-xmldsig/2002JanMar/0218.html

-- 

Joseph Reagle Jr.                 http://www.w3.org/People/Reagle/
W3C Policy Analyst                mailto:reagle@w3.org
IETF/W3C XML-Signature Co-Chair   http://www.w3.org/Signature/
W3C XML Encryption Chair          http://www.w3.org/Encryption/2001/
Received on Tuesday, 19 March 2002 16:36:49 GMT

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