[rules-users] Getting hold of the Evaluator Registry
Edson Tirelli
tirelli at post.com
Wed Jul 15 12:10:04 EDT 2009
root of your project "classpath", not root of your project.
[]s
Edson
2009/7/15 Asif Iqbal <Asif.Iqbal at infor.com>
> Hi Edson,
>
>
>
> I have gone away and tried the properties method of adding the
> customEvaluator, which worked fine for the code. But my IDE still does not
> pick it up. Any ideas?
>
>
>
> Do I need to place it in a META-INF folder in the root of the project?
>
>
>
> I have the following in the drools.packagebuilder.conf file.
>
>
>
>
> drools.evaluator.custom=com.infor.audit.bpr.component.validation.impl.drools.CustomComparableEvaluatorsDefinition
>
>
>
> thanks..
>
>
>
>
> ------------------------------
>
> *From:* rules-users-bounces at lists.jboss.org [mailto:
> rules-users-bounces at lists.jboss.org] *On Behalf Of *Edson Tirelli
> *Sent:* 15 July 2009 14:57
> *To:* Rules Users List
> *Subject:* Re: [rules-users] Getting hold of the Evaluator Registry
>
>
>
>
> Yes, you are in the right track, and I understand this is a bit
> confusing at first. One more reason for people to go to the October Rules
> Fest 2009 where I will give a presentation on all the ways to extend the
> engine to solve specific problems. It will be interesting I hope (last year
> was awesome) and even Charles Forgy will be there doing a presentation on
> Parallel Rete. :)
>
> Meanwhile I will write a tutorial on this, but just to help you there,
> your approach is correct, except that you don't need to setup the option for
> each operator. It works like this:
>
> * One EvaluatorDefinition class implements support to one or more
> evaluators, defined by the method public String[] getEvaluatorIds().
>
> * All you need to do, then, is wire you class once and the engine will
> pick-up all the IDs supported by that class. When you have your class wired,
> you give it a unique string identifier, so that if you ever need to replace
> it, or remove it, you will use that id. Sometimes we use the operator as the
> ID, but usually it is something that reminds you of the kind of evaluators
> that class define. For instance, drools registers the
> ComparableEvaluatorsDefinition in this way:
>
> drools.evaluator.comparable =
> org.drools.base.evaluators.ComparableEvaluatorsDefinition
>
> So in this case, "comparable" is the identifier. Finally, from my
> previous e-mail you will see that the reason that the eclipse IDE is still
> giving you errors is that you are using the API to configure the evaluators.
> Just move the configuration to the configuration file and the IDE will pick
> it up.
>
> []s
> Edson
>
>
> 2009/7/15 Asif Iqbal <Asif.Iqbal at infor.com>
>
> Edson,
>
>
>
> What I have done so far is created a CustomComparableEvaluatorsDefinition,
> which is exactly the same as the default ComparableEvaluatorsDefinition
> apart form having support for strings, which I have done by creating
> StringGreaterOrEqualEvaluators and added that in my custom class, using the
> addEvaluatorFunction :-
>
>
>
> addEvaluator( ValueType.SHORT_TYPE,
> Operator.GREATER, ShortGreaterEvaluator.INSTANCE );
>
> addEvaluator( ValueType.SHORT_TYPE,
> Operator.GREATER_OR_EQUAL, ShortGreaterOrEqualEvaluator.INSTANCE );
>
> addEvaluator( ValueType.PSHORT_TYPE,
> Operator.LESS, ShortLessEvaluator.INSTANCE );
>
> addEvaluator( ValueType.PSHORT_TYPE,
> Operator.LESS_OR_EQUAL, ShortLessOrEqualEvaluator.INSTANCE );
>
> addEvaluator( ValueType.PSHORT_TYPE,
> Operator.GREATER, ShortGreaterEvaluator.INSTANCE );
>
> addEvaluator( ValueType.PSHORT_TYPE,
> Operator.GREATER_OR_EQUAL, ShortGreaterOrEqualEvaluator.INSTANCE );
>
> //Custom additions
>
> addEvaluator( ValueType.STRING_TYPE,
> Operator.LESS, StringLessEvaluator.INSTANCE );
>
> addEvaluator( ValueType.STRING_TYPE,
> Operator.LESS_OR_EQUAL, StringLessOrEqualEvaluator.INSTANCE );
>
> addEvaluator( ValueType.STRING_TYPE,
> Operator.GREATER, StringGreaterEvaluator.INSTANCE );
>
> addEvaluator( ValueType.STRING_TYPE,
> Operator.GREATER_OR_EQUAL, StringGreaterOrEqualEvaluator.INSTANCE );
>
>
>
> Now Im am trying to wire it, with the following..
>
>
>
> CustomComparableEvaluatorsDefinition
> MyCustomComparable custom = *new* CustomComparableEvaluatorsDefinition();
>
> KnowledgeBuilderConfiguration config =
> KnowledgeBuilderFactory.*newKnowledgeBuilderConfiguration*();
>
> EvaluatorOption option = EvaluatorOption.*get*(*
> Operator.LESS.toString()*, custom);
>
> EvaluatorOption option2 = EvaluatorOption.*get*(*
> Operator.LESS_OR_EQUAL.toString()*, custom);
>
> EvaluatorOption option3 = EvaluatorOption.*get*(*
> Operator.GREATER.toString()*, custom);
>
> EvaluatorOption option4 = EvaluatorOption.*get*(*
> Operator.GREATER_OR_EQUAL.toString()*, custom);
>
>
>
> config.setOption(option);
>
> config.setOption(option2);
>
> config.setOption(option3);
>
> config.setOption(option4);
>
>
>
> Firstly is this the correct approach?....
>
>
>
> The problem im having is that in my drl files still flag errors, when I do
> “test” > “test2” , am I missing something?
>
>
>
> Regards
>
>
> ------------------------------
>
> *From:* rules-users-bounces at lists.jboss.org [mailto:
> rules-users-bounces at lists.jboss.org] *On Behalf Of *Asif Iqbal
> *Sent:* 15 July 2009 08:20
> *To:* Rules Users List
> *Subject:* RE: [rules-users] Getting hold of the Evaluator Registry
>
>
>
> Edson,
>
>
>
> Thanks for your replies they have really helped.
>
>
>
> 1) I am still not sure about creating a new operator, since the ‘>=’
> operator already exists it just does not cater for strings, which I want to
> add. So would creating a new operator cause the existing one to be
> overrriden when added to the registry?
>
>
>
> 2) Having looked at the examples and tests you emailed, I am still
> unsure how to actually wire in the changes, say for example I have replaced
> the existing ‘>=’ evaluator or created a new evaluator so that ‘>=’ now
> handles strings. When writing rules will the engine pick this up?.. or do I
> need to create a new jar by building?.. or do I need to update a
> configuration file?... im just not sure…
>
>
>
> 3) Wouldn’t the following also add the evaluator definition by
> replacing the existing one..
>
>
>
> *PackageBuilderConfiguration* pkgb = *new**PackageBuilderConfiguration()
> *;
>
> *pkgb.getEvaluatorRegistry()*.*addEvaluatorDefinition*(*new
> *ComparableEvaluatorsDefinition());
>
> *PackageBuilder* builder = *new** PackageBuilder(pkgb)*;
>
>
>
> *builder.addPackageFromDrl(source)*;
>
> *Package* pkg = *builder.getPackage()*;
>
> // Add the package to a *rulebase* (deploy the rule
> package).
>
> rules = *RuleBaseFactory.newRuleBase()*;
>
> *rules**.addPackage(pkg)*;
>
>
>
> Thanks for your help…
>
>
> ------------------------------
>
> *From:* rules-users-bounces at lists.jboss.org [mailto:
> rules-users-bounces at lists.jboss.org] *On Behalf Of *Edson Tirelli
> *Sent:* 14 July 2009 23:05
> *To:* Rules Users List
> *Subject:* Re: [rules-users] Getting hold of the Evaluator Registry
>
>
>
>
> I am working in one example of drools features where I implement a
> custom evaluator here:
>
>
> http://anonsvn.jboss.org/repos/labs/labs/jbossrules/contrib/lotrc/src/main/java/org/drools/examples/lotrc/evaluators/IsAdjacentToEvaluatorDefinition.java
>
> I use the configuration file instead of API in the example:
>
>
> http://anonsvn.jboss.org/repos/labs/labs/jbossrules/contrib/lotrc/src/main/resources/META-INF/drools.packagebuilder.conf
>
> []s
> Edson
>
> 2009/7/14 Edson Tirelli <tirelli at post.com>
>
>
> Asif,
>
> My recommendation is create a new operator for you instead of overriding
> existing ones. Although if you really want to replace the existing ones,
> setting the property or calling the API to register a new operator will
> override the default.
>
> See:
>
>
> http://anonsvn.jboss.org/repos/labs/labs/jbossrules/trunk/drools-compiler/src/test/java/org/drools/builder/KnowledgeBuilderConfigurationTest.java
>
> Test method:
>
> testEvaluatorConfiguration()
>
> []s
> Edson
>
> 2009/7/14 Asif Iqbal <Asif.Iqbal at infor.com>
>
> Hi,
>
>
>
> What I need to do is modify one of the evaluator classes specifically ‘<=’,
> so that it can handle strings. Now I know I need to create a class similar
> to ComparableEvaluatorDefinition. But what I want to do is replace the
> existing one in the evaluator registry with my implementation which will
> include the additional String capability.
>
>
>
> From my understanding that should be all that is required. Unless im
> missing something… now all I need to know is how do I get hold of the
> evaluator registry?
>
>
>
> Cheers
>
>
>
> I
>
>
>
> _______________________________________________
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> rules-users at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
>
>
>
> --
> Edson Tirelli
> JBoss Drools Core Development
> JBoss by Red Hat @ www.jboss.com
>
>
>
>
> --
> Edson Tirelli
> JBoss Drools Core Development
> JBoss by Red Hat @ www.jboss.com
>
>
> _______________________________________________
> rules-users mailing list
> rules-users at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
>
>
>
> --
> Edson Tirelli
> JBoss Drools Core Development
> JBoss by Red Hat @ www.jboss.com
>
> _______________________________________________
> rules-users mailing list
> rules-users at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
>
--
Edson Tirelli
JBoss Drools Core Development
JBoss by Red Hat @ www.jboss.com
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