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Subject: RE: where the qualifiers went...
Good People, The hanging question is when are we going to have a sound UML model for defining Core Components? It is difficult (and I believe counter-productive) to 'define' a core component (e.g., 'amount') when we haven't first defined and agreed upon a UML model. I would hope that the model that is developed would not support as a Core Component 'totalAmountInDollars' or 'shipToParty'. I would want the UML model to support 'Amount' in an 'atomic' manner such that the properties required to produce a 'whole/usable' semantic entity were an integral part of the definition of Amount. For 'amount', that would include a semantic definition (or to my preference, a pointer to a body of XML containing the definition in some standardized form); a data type (and by association to the data type class, a set of properties linked to that class, such as range limits); a currency designation (or a means to derive same from elsewhere in the document or schema); a semantic constraint (e.g., some (super/)subset of the ASC X12 DE 522 Amount Qualifier Code list. NOTE: The ASC X12 Amount Qualifier Code List is incomplete, because many segments which contain an 'Amount' DE use a semantic note in the segemnt definition to provide the semantic constraint to a single constraint value (e.g., to represent 'Net' amount).) How an 'amount' is represented in a particular syntax must not be a factor in defining 'amount' as a Core Component. I am perfectly comfortable with having multiple physical representations of an 'amount' in X12 syntax, in XML syntax, in EDIFACT syntax. That X12 chooses to use semantic notes in some cases to constrain semantic meaning, or perhaps uses a composite to relate the properties of an amount is not a problem to me. That one might define both an 'amount' XML element having fixed or variable attributes to specify properties, or having pointers to other elements which convey those same properties is not a problem to me. Defining a document in which there is no documented way to associate an amount with its required properties is a problem to me. It is instructive to look at each of the X12 segments in which one or more 'amount' DE's are defined. There are some instances in which a property of an 'amount' cannot be discerned from the segment documentation. There are also instances in which a semantic constraint property has multiple simultaneous values. And there is at least one instance in which the ability to express an amount in non-numeric terms is provided. Cheers, Bob -----Original Message----- From: Gregory, Arofan [mailto:arofan.gregory@commerceone.com] Sent: Thursday, May 31, 2001 2:05 PM To: 'William J. Kammerer'; ebXML Core Subject: RE: William defends Todd's dignity, too... and also wonders where the qualifiers went... William: There has been a good deal of discussion about the use of qualifiers generally in core components design in the working groups. I will attempt to paraphrase: In EDI syntaxes, qualifiers are used to indicate semantic specific to the local use of a re-usable component (for example, is this a Buyer party or a Ship To Party?) In some XML syntaxes, a similar approach is used (xCBL uses qualifying codes in many places, although certainly not everywhere, and usually for agreement with EDI syntaxes). In other XML syntaxes - especially those based on XML DTDs, which have a weaker concept of a "code list" or "enumerated datatype" - semantic qualification is performed with element containership. Now that we have a standard schema language to work with, that gives us strong typing capabilities, we have another mechanism for indicating semantic qualification with element names: a Buyer Party becomes an element named "BuyerParty" with a type attribute that indicates it is a "Party". In short, depending on how core components are bound to a syntax, qualifying codes may or may not be useful. I believe that the core components models did not indicate complete eumerations for the semantic qualifications of core components, but merely indicated the types of existing lists that might be useful. Ultimately, what we care about in the core component models is a range of standard uses, whether these are bound to a syntax as qualifying codes or with some other mechanism. Given the way XML processors work, I think it very likely that many XML formats will not use qualifying codes as the main way of indicating local semantic qualifications, because they are an inconvenient way to model XML data, having the disadvantage of containing within their content the information about what they are, rather than having this be present as a container, and thus immediately available to event-based processors such as those using a SAX interface. I may be wrong. Regardless, I don't think the issue is one of qualifying codes or not, but merely one of capturing a standard set of qualifiers that can be bound to specific syntaxes in many different ways. I hope this summary of discussion at some of the ebXML meeting will prove helpful. In response to Todd, I would say that perhaps we have not yet made the effort to enumerate all of the potential uses for these components. I believe that we have done a lot of work that may be useful in producing such an enumeration, but that this activity was not determined to be in scope up to this point. Maybe now is the time to start working on a standard set of local uses for each of the components? Cheers, Arofan Gregory -----Original Message----- From: William J. Kammerer [mailto:wkammerer@foresightcorp.com] Sent: Thursday, May 31, 2001 11:38 AM To: ebXML Core Subject: William defends Todd's dignity, too... and also wonders where the qualifiers went... Todd Boyle asks why don't the dateTime and Amount core components have qualifiers which explain what the dateTime and Amount are all about? This was a reasonable question which should be dignified with an answer. Perhaps it was missed because it was posted to the ebxml-dev mailing list rather than the Core Components mailing list. See http://lists.ebxml.org/archives/ebxml-dev/200105/msg00009.html. To repeat Todd's question: Is 'qualifier' in the doghouse? Anyway, Todd's asking the same questions I asked a long time ago, to which I never received an answer. See the third paragraph in http://lists.ebxml.org/archives/ebxml-core/200104/msg00279.html. Todd's question should be seriously mulled over - this is extremely relevant to Core Components design. And it is a bit more important than cat-fights over XML syntax. William J. Kammerer FORESIGHT Corp. 4950 Blazer Pkwy. Dublin, OH USA 43017-3305 +1 614 791-1600 Visit FORESIGHT Corp. at http://www.foresightcorp.com/ "accelerating time-to-trade" ------------------------------------------------------------------ To unsubscribe from this elist send a message with the single word "unsubscribe" in the body to: ebxml-core-request@lists.ebxml.org ------------------------------------------------------------------ To unsubscribe from this elist send a message with the single word "unsubscribe" in the body to: ebxml-core-request@lists.ebxml.org
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