RE: Postconditions with no XML elements defined?

   From: Lisa Dusseault [mailto:lisa@xythos.com]

   > The preconditions are statements that must be true for a method
   > to succeed,

   Sounds like if the precondition is not true the operation is "Forbidden",

   > and the postconditions are statements that must be true immediately
after
   the method has suceeded.

   Sounds like there must be a "Conflict" if the postcondition cannot be
met.

   If there are no strong objections, I propose that we adopt the simple
   normative rule a precondition is returned with 403 and a postcondition is
   returned with 409.

I'd fall into the "strong objection" camp.  403 means the user should
not retry the operation, because it will never succeed.  This will
sometimes be the case for both precondition and postcondition
failures.  409 means that there is something the user could do to the
resource to make the operation succeed.  This will also sometimes be
the case for both precondition and postcondition failures.

Cheers,
Geoff

Received on Thursday, 12 July 2001 10:37:13 UTC