Creating New Entity Instances within OPA

Question

This is another one that I think I know the answer to, but I think it is best to confirm.
In prior versions, it was not possible to create entity instances within RuleBurst/Haley Office Rules. Is that still the case in OPA?
For example, my rules are determining the status of a case and the reason(s) why that status was determined. The case status may be Denied and the reasons may be "invalid customer Id", "expenses to income ratio too high", "primary customer not employed long enough", etc. I want to return all the reasons for the status. While the list of reasons is pre-determined, the ones that apply to a particular case are dynamic, as any, but not all can apply.
Given this situation using a database, I would create an instance of reason for each applicable one and link it to the case. In the past, with OPA's predecessor(s), it was not possible to create new instances from within. They either had to all be passed into the rulebase or a list of all allowable reasons attributes had to be created and then set to true for the ones that applied.
My preference is to create the instances inside OPA. Is that functionality provided in the current version?
Thanks,
Terry

Answer 1

Hi Terry,
Michael is correct that you can't write rules at design time which will dynamically create new entity instances at runtime. However, perhaps the new inferred relationships functionality in v10 could address what you're trying to do.
You can write rules which conclude membership of an inferred relationship. So you might always have, say, 10 instances of 'the reason' in every case, but as for which of those instances apply in any particular case, it depends on the details of the case. You could use an inferred relationship to collect up the entity instances which apply in the case.
First you'd need to set up a regular one-to-many relationship to instantiate the 10 instances at runtime - this would be done in the usual way. Then you'd also need to set up an inferred relationship and write rules to conclude the members of the inferred relationship. The instances which are members of the inferred relationship are then effectively the list of entity instances you wanted to create in your example above.
Have a look at this OPM Help article: http://www.oracle.com/technology/products/applications/policy-automation/help/opm10_1/Content/Rules%20using%20entity%20instances/Reason_about_relship_between_2_entities.htm
Cheers,
Jasmine