SUBMITTED BY: Matthias Kloppmann
TARGET: BPEL4People Working Draft 02

DESCRIPTION: When are logical people groups re-evaluated, in particular for parameterized logical people groups.

Resolution of logical people groups happens on several occasions: When referenced from an htd:from clause, or when referenced from a getLogicalPeopleGroup XPath function. When accessed the first time through either means, a logical people group is evaluated. In a BPEL4People process, the same logical people group may be referenced again, possibly with a different set of arguments values. The specification needs to state what the rules are for re-evaluating (re-resolving) the logical people group.

PROPOSAL: Instances of an LPG are per set of values for the parameters. Consequently, when arguments of parameters are changed between referencing an LPG the first time and the second time, it MUST be re-evaluated/re-resolved. When parameters are not changed between referencing an LPG the first time and the second time, it MAY be re-evaluated/re-resolved.
(Motivation: Allow a modeler to reuse a logical people group, e.g., in a loop, with different bindings -- the example we discussed was regionalSalesPeople("Wales"), regionalSalesPeople("Sussex") -- you want to be sure the second one does not retrieve the former result, unless they are really the same. Allow in implementation for caching: When regionalSalesPeople("Wales") is called several times, the result could be cached, because re-resolution is not mandated.)