On Tue, 13 Jul 2004, Markus Hofmann wrote:
Alex Rousskov wrote:
- Defining an interface between rules language
and service (at least OCP-speaking service)
How to pass parameters to services? How to
get the result of service application, including
errors, back to the language/program?
I would consider passing of parameters and getting results back into
the language/program in scope. Any other thoughts?
I agree. Supporting just that in a general way is already difficult!
We are talking about any P program being able to pass any parameters
to any service in scope (e.g., any OCP-speaking or perhaps
WSDL-describable OPES service). How will P interpreter know what
parameters are available? Which parameters are optional? What are their
types?
I hope that we can decide on specific mechanisms after we settle on
the charter, but I wonder if we should now decide on whether to
accommodate just OCP-speaking services or something broader like
WSDL-describable services (assuming we can use WSDL core to describe
any OCP-speaking service).
OCP-speaking services already have a PETDM-driven "feature" interface
that can probably be used to infer the set of parameters, but handling
PETDM declarations may require human involvement. Is that good enough?
If human involvement is required, any P interpreter would have to
hard-code known OCP feature descriptions instead of being able to
handle any "registered by administrator" OCP feature. A big difference
from deployment point of view! You have to know all feature profiles
in advance...
If we do not want human involvement, we have to use something like
WSDL (and map WSDL to P and to OCP PETDM feature declarations) or make
OCP PETDM notation more formal so that it can be processed by P
interpreters to extract feature interfaces. Either task is quite a
challenge.
Alex.