How many Party (es) do you have? in the session? Are you sure that partyType.trim() returns "" ? Cheers On Tue, Dec 20, 2011 at 7:36 PM, freejava <freejava3(a)gmail.com&gt; wrote: --  - CTO @ http://www.plugtree.com  - MyJourney @ http://salaboy.wordpress.com  - Co-Founder @ http://www.jugargentina.org  - Co-Founder @ http://www.jbug.com.ar  - Salatino "Salaboy" Mauricio -

Do you understand the difference between: Party( $e : errors) Party(partyType != null, partyType.trim() != "", partyType not in ("MF", "SE", "BY", "ST", "LG", "CS", "CN")) and Party($e : errors, partyType != null, partyType.trim() != "", partyType not in ("MF", "SE", "BY", "ST", "LG", "CS", "CN")) On Wed, Dec 21, 2011 at 12:38 PM, freejava <freejava3(a)gmail.com&gt; wrote: --  - CTO @ http://www.plugtree.com  - MyJourney @ http://salaboy.wordpress.com  - Co-Founder @ http://www.jugargentina.org  - Co-Founder @ http://www.jbug.com.ar  - Salatino "Salaboy" Mauricio -

no.. the first option Looks for two instances of Party() and the second just for one instance of Party() No, if you bind a variable inside a Pattern, the $e variable in your case will contain only the errors from the party that matches. The second rule will evaluate two instances of Parties, that means that if you have more than one Party instance inside your working memory, a cross product will be generated with all the possibilities, causing more activations that the ones that you need. Using two patterns is similar to do in sql select * from party and joining that with select * from party Cheers On Wed, Dec 21, 2011 at 2:05 PM, freejava <freejava3(a)gmail.com&gt; wrote: --  - CTO @ http://www.plugtree.com  - MyJourney @ http://salaboy.wordpress.com  - Co-Founder @ http://www.jugargentina.org  - Co-Founder @ http://www.jbug.com.ar  - Salatino "Salaboy" Mauricio -

I bet this : your error list is the same instance, shared in all Party objects... Am I right ? And why do you need to pass "drools" to your "appendMessage" method ? Do you modify (insert/update/retract some objects) the WM inside this method ? Be very careful if you do that (especially if you said you are new to drools), it could leads to some number of hours wondering why this rule is looping, not trigering .... Better (IMO) is to use update/retract/insert only in rules. ----- Mail original ----- De: "freejava" <freejava3(a)gmail.com&gt; À: rules-users(a)lists.jboss.org Envoyé: Mercredi 21 Décembre 2011 18:53:23 Objet: Re: [rules-users] Rules Hello Evalution Thanks for the explanation. I think I got it. Here is my scenario: I have n number of parties in the memory. I have to perform the validation on each party for the party type. If it fails then add an error message(just one) to the collection of that particular party. So I rewrote the rule as below rule "041" when Party(partyType != null, partyType.trim() != "", partyType not in ("MF", "SE", "BY", "ST", "LG", "CS", "CN"), $e : dentificationGrp.errors) then appendMessage($e, drools) end Now I have two objects : p1 : Party(partyType=*"SE *", List<String> errors) and p2 : Party(partyType=*"CS "* ,List<String> errors); After consequence is fired both p1 and p2 has 2 error message of type "041". where as the expected result should be 1 error message for p1 and p2. How can I acheive that ? -- View this message in context: http://drools.46999.n3.nabble.com/Rules-Evalution-tp3602504p3604691.html Sent from the Drools: User forum mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users

Have a look there too : http://drools.46999.n3.nabble.com/quot-Rule-Id-quot-for-a-Drools-Rule-td2... or use a WorkingMemoryEventListener and a AgendaEventListener together to set the name for all freshly inserted objects.