- From: <Noah_Mendelsohn@lotus.com>
- Date: Wed, 20 Jun 2001 19:12:07 -0400
- To: xml-dist-app@w3.org
- Cc: jcowan@reutershealth.com, pgrosso@arbortext.com
Quick background for those not in the Protocols WG: there has been some semi-formal discussion in the protocols WG as to whether it might be appropriate to adopt, in one of various possible ways, XML Infosets as the fundamental means of describing an XMLP message. Without going into details, the general idea would be to have XMLP specify the contents of messages in the form of Element and Attribute Information items. Particular bindings, such as the http binding, could then decide on the exact representation of the XML on the wire (ordinary well-formed, compressed, encrypted, something else, etc.). Anyway, on an XMLP WG teleconference today I was asked to post this note to the dist App list. The purpose of this note is not primarily to start a discussion of the merits of the above proposal: indeed, the WG is still considering whether and in what form to make such a proposal. Rather, I have been asked to mention a specific aspect of the Infoset Candidate recommendation draft that is perhaps less than ideal for our purposes. Specifically, the CR Infoset draft states [1]: "This document specifies an abstract data set called the XML Information Set (Infoset), a description of the information available in a well-formed XML document [XML]. "XML 1.0 documents that do not conform to [Namespaces], though technically well-formed, are not considered to have meaningful information sets as defined by this specification. That is, this specification does not define an information set documents that have element or attribute names containing colons that are used in other ways than as prescribed by [Namespaces]. There is no requirement for a XML document to be valid in order to have an information set." The potential problem is that this text, though arguably a bit ambiguous, strongly suggests that well formed documents come first, and then Infosets must be derived from them. There are important use cases, such as in XMLP, in which XML infosets should describe documents that may not initially (or ever) exist in the form of a sequence of Unicode characters with "<...>" syntax. As a trivial example, consider an empty DOM to which a program adds element and attribute nodes. Surely there is an Infoset, but no " <...>". Indeed, this is likely to be the common case for the sender of an XMLP message. If the binding sends an encrypted form, there need not at any time be "<" form or a conventional parser at the receiver; the SOAP processor might go directly from encrypted to SAX/DOM/etc. at the receiving end. The specific question on the table is: should the XMLP WG send a comment to the Infoset (core) group recommending a change to the introduction of the XML Infoset candidate rec.? Note: to avoid cross-posting, this is being mailed only to dist-app. This is intended to start discussion within the community working on XMLP to decide whether a formal (or informal) approach to the Infoset group should be made. Obviously, discussion from members of that group (or others) is welcome in response to this note. [1] http://www.w3.org/XML/Group/2000/03/WD-infoset-20000331.html#intro ------------------------------------------------------------------------ Noah Mendelsohn Voice: 1-617-693-4036 Lotus Development Corp. Fax: 1-617-693-8676 One Rogers Street Cambridge, MA 02142 ------------------------------------------------------------------------
Received on Wednesday, 20 June 2001 19:17:04 UTC