Thanks..
________________________________
From: [email protected]
[mailto:[email protected]] 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 <[email protected]<mailto:[email protected]>>
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:
[email protected]<mailto:[email protected]>
[mailto:[email protected]<mailto:[email protected]>]
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:
[email protected]<mailto:[email protected]>
[mailto:[email protected]<mailto:[email protected]>]
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 <[email protected]<mailto:[email protected]>>
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 <[email protected]<mailto:[email protected]>>
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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--
Edson Tirelli
JBoss Drools Core Development
JBoss by Red Hat @ www.jboss.com<http://www.jboss.com>
--
Edson Tirelli
JBoss Drools Core Development
JBoss by Red Hat @ www.jboss.com<http://www.jboss.com>
_______________________________________________
rules-users mailing list
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--
Edson Tirelli
JBoss Drools Core Development
JBoss by Red Hat @ www.jboss.com<http://www.jboss.com>
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