Wolfgang Laun wrote: > 2010/1/31 <[email protected]> > >> Wolfang, >> >> thank you very much for your reply. >> >> Your assumptions are correct and your explanation makes sense. >> Unfortunately, I cannot understand why this happens. >> >> > It may very well be an implementation restriction; whether it can be > removed easily I'm not prepared to say. (@Edson?)
Fair enough. > > >> The IUEcop has the following structure (in rough terms) >> IUEcop >> +- (various objects as properties) >> +- list of traderAuthorisation >> +- list of warehouseAuthorisation >> +- list of temporaryAuthorisation >> >> >> A more general issue with my understanding has to do with handling of >> deeply nested objects. In my case, the "traderAuthorisation" object has >> itself another set of object properties and lists that I would like to >> refer to in my rules. Are you aware of any relevant documentation? >> > > Nested objects that are not facts but shared between fact objects should > not > cause any problems; especially the MVEL syntax is provided for easy > access to properties of a property. > > If such an object is shared among several fact objects, you'll have a > problem whenever such a shared object is updated by code on a RHS: > To trigger reevaluation of rules, the engine would have to be > notified about all objects referring to the shared object as being > updated. Although in my case the objects are not shared, I understand the issues involved. > > Lists is adding another twist, even though the "from" CE appears > to simplify handling of Iterable properties and works well enough. > The recommended (see Drools Expert, section 4.8.2.8, Conditional > Element "from") alternative is to add List elements as WM elements > of their own, I was hoping to avoid this. This is how I was doing things in Prolog, but I was hoping that object-orientation would help tackling this issue. Anyway, thanks a lot for your help. -Stathis > even though this may require the addition of linking > information to the list elements. (In your case: a TraderAuthorisation > would have to contain a reference to the IUEcop object it belongs > to.) You'll have to balance the additionally required coding effort > for this against the greater complexity of rules using "from". > > -W > > >> Thank you very much for your time, >> -Stathis >> >> > _______________________________________________ rules-users mailing list [email protected] https://lists.jboss.org/mailman/listinfo/rules-users
