March 2007 - rules-users - Jboss List Archives

The use of final global variable into the LHS part of rule...

by nicolae oana

Hi everybody, It is possible to use a final global variable into the LHS part of a rule? Since the final global variable is in fact a global constant I think it will be ok to use it in some predicate expression or into an eval of a rule. But I get this ugly exception, when I'm trying to use my global in the LHS part of the rule: Exception in thread "main" org.drools.RuntimeDroolsException: java.lang.NullPointerException I mention that when I use the same global variable in the RHS part of the rule, everything works fine, and I'm getting the appropriate results. Best regards, Oana --------------------------------- Looking for earth-friendly autos? Browse Top Cars by "Green Rating" at Yahoo! Autos' Green Center.

18 years, 10 months

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bug in 3.1M?

by Olenin, Vladimir (MOH)

Hi, I've run across one thing. If I evaluate two columns within 'exists' statement it throws compilation error if I don't connect two columns with 'and': Exists ( Column (...) Column (...) ) With 'and' everything compiles OK: Exists ( Column (...) and Column (...) ) Which is correct? Or probably both are not correct? From the 3.1M release notes I can suggest there is another syntax (which works as well): Exists ( Column (...) and Exists Column (...) ) I thought #1 should work OK.... I'm not sure what #2 might mean for DROOLS. >From the rules & data I'm processing and results I'm getting it seems like it works as #1 should, ie, checking existence of the tuple represented by the columns within the 'exists' block.... Thanks, Vlad

18 years, 10 months

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Newbie question: can I create a variable in the rules file?

by Rented User

Hi, I'm mew to this rules stuff, and although I've looked at rules engines such as Corticon before, I got introduced to JBoss Rules through JBoss Seam's security mechanism. I'm trying to expand on Seam's built in functionality to assess a user's permissions. My use case is that a user of the system may or may not have permission to a resource based on the user's role AND the current date. The system accepts certain actions only if "now" is between a certain start and end date. What I'd like to do is something like this: rule CanDoHisStuff activation-group "permissions" when c: PermissionCheck(name == "stuff", action == "do", granted = false) now: new Date() <--------------------------------------------------------------How can I accomplish this? ap: AppProps() Role(name == "A Role") eval(now >= ap.startDate, now <= ap.endDate) then c.grant(); end; Now, I understand that in my code, I could assert an object "now". However, a lot of the security is hidden behind the scenes in Seam. For example, this rules will be fired from an XML definition file. E.g. <page view-id="/restricted/doStuff.xhtml"> <restrict>#{s:hasPermission('stuff', 'do', null)}</restrict> <navigation from-action="#{createStuffManager.yesConfirmSave}"> <end-conversation/> <redirect view-id="/restricted/viewStuff.xhtml"/> </navigation> </page> While I could start extending Seam's security model, that seems a bit invasive for such a simple task. Thanks /Kris

18 years, 10 months

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Rete diagram legend - what do all the colors mean?...

by Olenin, Vladimir (MOH)

Hi, I was trying to make some sense out of Rete Diagram for my rules (DROOLS 3.1M), and one of the questions I have is what all these colors mean? There are red, blue, yellow, green, orange, white, cyan and black circles.... I might be wrong, but I think this should mean something! Also, I noticed that by default the diagram is displayed in 'layers' of dots. In my case I have 7 layers, the top one being the 'root' I assume (single white circle). The 'widest' layer is the middle one - the forth layer. So, generally the diagram has a diamond shape. I wonder if one can use this kind of visual information to make a rough estimation/assumption on how efficient his rules/constraints are, some hints into optimization, etc.... Thanks, Vlad

18 years, 10 months

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list iteration

by vijay nooka

can any one help in iterating an arraylist holding finite no of objects, each individual objects holds the details of the object.. for example Boxlist holding different box objects and individual box object holds the detals of box color,box length and etc..please give me the DSL syntax for iterating this box list...and syntax should support the condition such that we should assert the boxlist object (i.e mylist object as per the below conditons) in to working memory.. here BoxList is the class extends ArrayList BoxList mylist=new BoxList(); mylist.add(new boxclass("red","10","20","5"); mylist.add(new boxclass("red","40","20","10"); mylist.add(new boxclass("red","50","40","20"); . . . etc are added in to mylist plz explan the syntax clearly as i had seen some syntax which is confusing me.... thanks vijay -- View this message in context: http://www.nabble.com/list-iteration-tf3375504.html#a9393812 Sent from the drools - user mailing list archive at Nabble.com.

18 years, 10 months

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[Newbie] XML Package Reader: how to avoid this exception?

by Fabio Genovese

Hi everybody. I'm a happy user of the Drools 3.0.5 XML package reader, it seems working fine, but when I try to include an extra library (not Drools-related) in my build path, comes up this exception: Exception in thread "main" java.lang.RuntimeException: AElfred parser is non-validating at org.drools.xml.XmlPackageReader.read(Unknown Source) at org.drools.xml.XmlPackageReader.read(Unknown Source) at org.drools.compiler.PackageBuilder.addPackageFromXml(Unknown Source) at com.sample.PackageWriter.main(PackageWriter.java:39) It won't occur if I remove this "extra" library from build path (which uses a XML parser as well). Maybe I need to specify which parser Drools needs to load, but I don't know how. Sorry, I don't have enought java/xml experience to solve this. Could someone help me? Thanks in advance. FG

18 years, 10 months

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Package declaration problem

by dileep_sivaraman

Our drl file snippet looks something like this : Snippet : When we try to fire the rules we get the following exception. org.drools.rule.InvalidRulePackage: Function Compilation error Rule Compilation error The import com.bofa.TS cannot be resolved When we change the package from "com.bofa.strata.component.rules" to "com.bofa.TS.AIM.IV" ,it compiles fine. Queries : 1) How do we arrive at a safe package name? 2) On what basis is the error thrown ? -- View this message in context: http://www.nabble.com/Package-declaration-problem-tf3374958.html#a9392040 Sent from the drools - user mailing list archive at Nabble.com.

18 years, 10 months

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RE: [rules-users] 'from accumulate' doesn't work on multiple colu mns?..

by Olenin, Vladimir (MOH)

> Edson wrote: ------------- 3. Regarding the distinct, I'm not sure if it would be good to have such "feature". Need further discussion I guess. But on of the ways to work around that is just to have a "driver" fact. I mean, if "f1" means a financial account, for instance, have a Financial Account fact: -- End of quote Yes, that's how I'm dealing with it right now... But you (or Mark?) mentioned some time ago regarding similar issue ("Convert logic to DRL rules") that it's better to aviod this kind of 'indexing' and keep the data model 'flattened' since it'd allow for more optimizations on DROOLS side. In my case 'Record' fact has 6-7 fields and the type of rules I have would require to have such index on almost all these fields (which means I'd have to assert 'unique value' facts for each of the fields). So, I thought this kind of problem (as well as combination of unique fields) can be solved easily with having such keyword ('distinct' or 'unique' or smth like that). I think that even implementation should not be very difficult, since it would just require to get all facts of particular type and assert a new set of 'unique value' facts for each of the fields used in the constraint... Kind of preprocessing step. But I think such index (index of all fields within particular fact type) might already being created as part of other algorithms?... Vlad -----Original Message----- From: rules-users-bounces(a)lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Edson Tirelli Sent: 07 March 2007 17:43 To: Rules Users List Subject: Re: [rules-users] 'from accumulate' doesn't work on multiple columns?.. Vlad, Trying to answer both of your e-mails in this one. 1. Right now, accumulate supports only a single Pattern (column), as you already realized. That is a limitation we want to remove before the next final release, but it is not done yet. I already know how to fix that, but didn't had the time to do it yet. We are working hard in the BRMS side now. If anyone is willing to help with that, I can provide the instructions on how to do the implementation for that feature. 2. Regarding matching the same fact multiple times in a single tuple, this is a configuration. In 3.0.x, the default is to not allow the same fact to be matched multiple times in a single tuple. In 3.1, the default was changed to allow multiple matches. That is why your tested matched multiple times. This is one of the BIG warnings we need to add to the upgrade documentation. 3. Regarding the distinct, I'm not sure if it would be good to have such "feature". Need further discussion I guess. But on of the ways to work around that is just to have a "driver" fact. I mean, if "f1" means a financial account, for instance, have a Financial Account fact: rule ... when FinancialAccount( $id : id ) Double( doubleValue > 0 ) from accumulate( Record( finId == $id, $f2 : f2, $val : value ) init( double sum = 0; ) action( sum += ( $f2 < 10 ) ? $val : -$val; ) result( new Double( sum ) ) ) then // do something end Hope it helps. []s Edson Olenin, Vladimir (MOH) wrote: > This is as a follow up for the previous question.... It looks like I > made a wrong assumption that 'accumulate' can work on multiple columns: > > Integer ( intValue > 0) from accumulate ( > > Record ( f1 == $f1, f2 < 10, $value1 : value ) > > Record ( f1 == $f1, f2 >= 10, $value2 : value ) > > Init ( int sum = 0; ), > > Action ( sum += $value1 - $value2 ), > > Result ( new Integer (sum) ) > > ) > > I'm getting an error ('then' is expected or smth like that at the > point where the second 'Record' is defined) and the only way to remove > the error is to declare one and only one Column constraint... So, it is > not possible then to use multiple columns in 'accumulate'? If not, > then it would be even more interesting to get some idea on how to > approach the kind of problem I mentioned in the previous post..... > > Thanks, > > Vlad > >------------------------------------------------------------------------ > >_______________________________________________ >rules-users mailing list >rules-users(a)lists.jboss.org >https://lists.jboss.org/mailman/listinfo/rules-users > > -- Edson Tirelli Software Engineer - JBoss Rules Core Developer Office: +55 11 3124-6000 Mobile: +55 11 9218-4151 JBoss, a division of Red Hat @ www.jboss.com _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users

18 years, 10 months

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RE: [rules-users] 'from accumulate' doesn't work on multiple colu mns?..

by Olenin, Vladimir (MOH)

Thanks, Edson. That explains it. Regarding your #1 point, I can try to help, especially if it's smth that won't require digging deeply into DROOLS implementation details (and would help me to implement the rule I mentioned in the previous post :) )... How much time do you think it will take providing I'm not familiar with DROOLS codebase? (DROOLS dev-t environment setup + this feature implementation) I'm subscribed to dev-t list (from what I recall), so we can move this discussion there... Thanks, Vlad -----Original Message----- From: rules-users-bounces(a)lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Edson Tirelli Sent: 07 March 2007 17:43 To: Rules Users List Subject: Re: [rules-users] 'from accumulate' doesn't work on multiple columns?.. Vlad, Trying to answer both of your e-mails in this one. 1. Right now, accumulate supports only a single Pattern (column), as you already realized. That is a limitation we want to remove before the next final release, but it is not done yet. I already know how to fix that, but didn't had the time to do it yet. We are working hard in the BRMS side now. If anyone is willing to help with that, I can provide the instructions on how to do the implementation for that feature. 2. Regarding matching the same fact multiple times in a single tuple, this is a configuration. In 3.0.x, the default is to not allow the same fact to be matched multiple times in a single tuple. In 3.1, the default was changed to allow multiple matches. That is why your tested matched multiple times. This is one of the BIG warnings we need to add to the upgrade documentation. 3. Regarding the distinct, I'm not sure if it would be good to have such "feature". Need further discussion I guess. But on of the ways to work around that is just to have a "driver" fact. I mean, if "f1" means a financial account, for instance, have a Financial Account fact: rule ... when FinancialAccount( $id : id ) Double( doubleValue > 0 ) from accumulate( Record( finId == $id, $f2 : f2, $val : value ) init( double sum = 0; ) action( sum += ( $f2 < 10 ) ? $val : -$val; ) result( new Double( sum ) ) ) then // do something end Hope it helps. []s Edson Olenin, Vladimir (MOH) wrote: > This is as a follow up for the previous question.... It looks like I > made a wrong assumption that 'accumulate' can work on multiple columns: > > Integer ( intValue > 0) from accumulate ( > > Record ( f1 == $f1, f2 < 10, $value1 : value ) > > Record ( f1 == $f1, f2 >= 10, $value2 : value ) > > Init ( int sum = 0; ), > > Action ( sum += $value1 - $value2 ), > > Result ( new Integer (sum) ) > > ) > > I'm getting an error ('then' is expected or smth like that at the > point where the second 'Record' is defined) and the only way to remove > the error is to declare one and only one Column constraint... So, it is > not possible then to use multiple columns in 'accumulate'? If not, > then it would be even more interesting to get some idea on how to > approach the kind of problem I mentioned in the previous post..... > > Thanks, > > Vlad > >------------------------------------------------------------------------ > >_______________________________________________ >rules-users mailing list >rules-users(a)lists.jboss.org >https://lists.jboss.org/mailman/listinfo/rules-users > > -- Edson Tirelli Software Engineer - JBoss Rules Core Developer Office: +55 11 3124-6000 Mobile: +55 11 9218-4151 JBoss, a division of Red Hat @ www.jboss.com _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users

18 years, 10 months

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drools 3.0.5 xml tutorials

by dileep_sivaraman

can any one suggest a good tutorial which gives a start on the basics of writing a drl file in xml format -- View this message in context: http://www.nabble.com/drools-3.0.5-xml-tutorials-tf3374095.html#a9389400 Sent from the drools - user mailing list archive at Nabble.com.

18 years, 10 months

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rules-users March 2007