Re: [rules-users] Insert new facts in WorkingMemory event handler

Hi Michael, Thanks for you answer! Following you suggestion I've taken a look at at "logical insertions" and on one hand I have to say that it looks like what I need, but on the other hand it is not clear to me how to "implement it". If you have some time to take a look, here are the objects in my session: - one T object (something that can be considered as a "type" object) - many I objects (something that can be considered as "instance" objects), I objects have one "type" field beeing a T (there is no link from T to Is) Those facts are inserted into the session and I have the impression that we are not speaking here of logical insertions: they have to be here, it is the input data the user has to write rules on. The user can decide to retract the T object: in this case all I objects have to be retracted as well. The user can decide to retract some I objects: when all of them have been retracted, the T object should be retracted as well. The first "solution" I imagined was to have high-salience rules: rule "1" when t : T not I(type == t) then retract t rule "2" when i : I(t : type) not Type (this == t) then retract i The other solution I imagined (that I have not tried) was to retract facts using a WorkingMemoryEventHandler. However as I am a Drools' absolute beginner (not only to Drools, but to the rule paradigm itself), I was wondering what is the "most natural way" for you guys to implement that behavior :-). Bruno. Michael Anstis a écrit :