RE: [rules-users] Constaint evaluation

Thanks Kris, I will try with code constraints. But on the globals subject, I read in the documentation that one should not use a global in a rule. I have trouble understanding why. I don't think drools clones the global object (might not be possible anyway). If my rule consequences change the state of a global (this usage is considered valid as per the documentation as well) then what is the harm of using it in a condition? I could understand with immutable objects like String but... I can change my code to insert that global in the working memory but I would like to understand why I should do so... And if I do and the state of that object is changed by a consequence of my rules, I have to call update? For the same reason? I guess I am trying to understand the underlying mechanism. Thanks -----Original Message----- From: Kris Verlaenen [mailto:Kris.Verlaenen@cs.kuleuven.be] Sent: Wednesday, June 10, 2009 11:38 AM To: Rules Users List; Malenfant, Andre Cc: Rules Users List Subject: Re: [rules-users] Constaint evaluation It depends on what type of constraint you are using. If you are using a rule constraint, that constraint will be evaluated just the same as normal rules. This means that the constraints are evaluated when data is inserted / updated / removed. Note that, if you want to make sure the engine is using up-to-date information, you must notify the engine (using update) when you change the data in the working memory. Also note that globals are considered immutable. You should never write rules that depend on the state of a global and where the global can be changed. If you are using code constraints, the constraint is evaluated at the point the code constraint is reached. Kris Quoting "Malenfant, Andre" <andre.malenfant(a)cgi.com&gt;: > I have some trouble understanding how conditions and constraints are > evaluated: > > I have a rule flow split node with constraints on a global object. > The split node always takes the same path like if the constraints are > evaluated at the beginning of the execution of the process and not > when the process flow reaches that split node. What I would expect is > that the split node constraints takes into account the state of the > global object as modified by previous rules in the flow. > > Am I right to think that rules conditions and split nodes constraints > are evaluated only when inserting/updating objects in the working > memory? The documentation is not really useful (unless I haven't > found the appropriate one). > > Thanks > > André > > -----Original Message----- > From: rules-users-bounces(a)lists.jboss.org > [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Malenfant, > Andre > Sent: Wednesday, June 10, 2009 11:07 AM > To: Kris Verlaenen > Cc: Rules Users List > Subject: RE: [rules-users] Globals in ruleflow > > Thanks for trying this for me... > > As it turns out, while I was creating a test sample for you I > realized > that my ruleflow was not loading properly and I forgot to check for > errors on the builder. Now it works. > > Still, the behavior is strange. If my rule doesn't load and even > though > my DRL loaded, my globals were not available. Since the DRL declared > the > same globals it should not have given me that error. > > Thanks > > -----Original Message----- > From: Kris Verlaenen [mailto:Kris.Verlaenen@cs.kuleuven.be] > Sent: Tuesday, June 09, 2009 5:51 PM > To: Rules Users List; Malenfant, Andre > Cc: Rules Users List > Subject: Re: [rules-users] Globals in ruleflow > > Andre, > > There should be no problem in using the same global in both your > rules > and processes. > > I have tried a simple example as you described but have not been able > to > reproduce the problem. Could you send me a self-contained example > that > shows the issue? > > Kris > > Quoting "Malenfant, Andre" <andre.malenfant(a)cgi.com&gt;: > > > I am experimenting with rule flows and I get the following error: > > > > Unexpected global [myglobal] > > > > When calling setGlobal on the session. > > > > This code works without the workflow (globals declared in the drl) > > but > > fails when I include the rule flow. I declared the same globals in > > the > > rule flow in the header section. > > > > _______________________________________________ > > rules-users mailing list > > rules-users(a)lists.jboss.org > > https://lists.jboss.org/mailman/listinfo/rules-users > > > > > > > Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm > > _______________________________________________ > rules-users mailing list > rules-users(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > > _______________________________________________ > rules-users mailing list > rules-users(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users