RE: More use cases

The answer is "it depends".
 
Errors associated with formatting of the overall message (e.g. HTTP, MIME or
SOAP errors) should be handled at a lower level. At the other extreme some
errors, e.g. "product code not recognized" can "only" be determined by the
application/process/service that is processing the content of the message
as, in this example, it requires validation against a database.
 
There are also some validation errors of the content of mesages that fall in
the grey area inbetween. 
 
These can sometimes be detected by an XML Parser by validating against the
XML Schema and therefore could be considered as being handled at a lower
level, for example an XML parser could check that a product code must be 10
characters alphanumeric and provide an "invalid format" error if it was not.
 
Sometimes though the application has to do the check.One example would be
checking the validity of a postal code as it is dependent on the country
associated with the address. e,g, - a valid US Postal code must be numeric
e.g. "94511" and in a UK code a Postal Code is alphanumeric with a space in
the middle, e.g. "KT11 2EN"
 
Since errors "sometimes" have to be handled by the
application/process/service I think we have to consider them when designing
our approachy to handling choreographies.
 
Hope this helps.
 
David
-----Original Message-----
From: Stephen White [mailto:swhite@SeeBeyond.com]
Sent: Wednesday, April 02, 2003 11:19 AM
To: Burdett, David; WS Choreography (E-mail)
Subject: RE: More use cases


David,
 
Is the handling of errors for every message something that should be in the
choreography? If included, then it could prove to be an infinite cycle-e.g.,
there is an error in the error response message, which is handled as an
error, and so on. This seems like another protocol that should be layered
below the choreography. True?
 
-Steve
 
-----Original Message-----
From: Burdett, David [mailto:david.burdett@commerceone.com]
Sent: Tuesday, April 01, 2003 1:08 PM
To: WS Choreography (E-mail)
Subject: More use cases
 
Martin sending out a use case reminded me of another use case involving
dependencies between choreographies that I want to provide.
David 
<<Choreography Dependency use case.htm>> 
Director, Product Management, Web Services 
Commerce One 
4440 Rosewood Drive, Pleasanton, CA 94588, USA 
Tel/VMail: +1 (925) 520 4422; Cell: +1 (925) 216 7704 
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