[rules-users] RE: Duplicate check using dialect(firing multiple times)
Edson Tirelli
tirelli at post.com
Thu Nov 15 10:38:25 EST 2007
Basha,
This is the correct behavior since both facts match both patterns (one
at a time). If you don't want them to fire 2 times, you need a way to tell
the engine there is an order on the facts. I.e., (A,B) is a valid tuple for
you, but (B,A) is not.
One way of doing that is if the facts have some ID attribute that can be
ordered:
$f1 : Message( $id1 : id, $m1 : message )
$f2 : Message( id > $id1, $m2 : message == $m1, eval( $f1 != $f2 ) )
If your facts have no attribute that allow a user to establish an order
between them, then the only way is to use java system id to do that:
$f1 : Message( $m1 : message )
$f2 : Message( $m2 : message == $m1, eval( System.identityHashCode(
$f1 ) > System.identityHashCode( $f2 ) ) )
[]s
Edson
2007/11/15, Sikkandar Nawabjan <Sikkandar.Nawabjan at ust-global.com>:
>
> Edson,
>
> With this code it is firing. But it is firing 2 times(u also got same 2
> time output). why is that? how we can avoid?
>
> Thanks and Regss,
>
> Basha
>
>
>
>
>
>
>
> Sorry, my mistake. "this" is a reserved word in java (duh!!), and so
> you need to use your own binding:
>
> m : Message( $message1 : message )
> mdup : Message($message2:message==$message1,eval(mdup != m) )
>
> You can't use mvel dialect, because in MVEL the operators "==" and "!="
> will call the equals() method anyway.
> Other than that, it is working just fine for me:
>
> rule "Find duplicates"
> salience 10
> when
> $f1 : Message( $m1 : message )
> $f2 : Message( $m2 : message == $m1, eval( $f1 != $f2 ) )
> then
> System.out.println( "FIRED DUPLICATE:" );
> System.out.println( " $f1 = "+$f1+" [ message="+$m1+" ]" );
> System.out.println( " $f2 = "+$f2+" [ message="+$m2+" ]" );
> end
>
> rule "Find differents"
> when
> $f1 : Message( $m1 : message )
> $f2 : Message( $m2 : message != $m1 )
> then
> System.out.println( "FIRED DIFFERENT:" );
> System.out.println( " $f1 = "+$f1+" [ message="+$m1+" ]" );
> System.out.println( " $f2 = "+$f2+" [ message="+$m2+" ]" );
> end
>
> The code to insert facts is:
>
> Message message1 = new Message();
> message1.setMessage( "Hello World" );
> workingMemory.insert( message1 );
> Message message2 = new Message();
> message2.setMessage( "Hello World" );
> workingMemory.insert( message2 );
> Message message3 = new Message();
> message3.setMessage( "Hello Bob" );
> workingMemory.insert( message3 );
> workingMemory.fireAllRules();
>
> And the result is:
>
> FIRED DUPLICATE:
> $f1 = com.sample.DroolsTest$Message at 1b06041 [ message=Hello World ]
> $f2 = com.sample.DroolsTest$Message at 1a001ff [ message=Hello World ]
> FIRED DUPLICATE:
> $f1 = com.sample.DroolsTest$Message at 1a001ff [ message=Hello World ]
> $f2 = com.sample.DroolsTest$Message at 1b06041 [ message=Hello World ]
> FIRED DIFFERENT:
> $f1 = com.sample.DroolsTest$Message at 1c6572b [ message=Hello Bob ]
> $f2 = com.sample.DroolsTest$Message at 1b06041 [ message=Hello World ]
> FIRED DIFFERENT:
> $f1 = com.sample.DroolsTest$Message at 1b06041 [ message=Hello World ]
> $f2 = com.sample.DroolsTest$Message at 1c6572b [ message=Hello Bob ]
> FIRED DIFFERENT:
> $f1 = com.sample.DroolsTest$Message at 1c6572b [ message=Hello Bob ]
> $f2 = com.sample.DroolsTest$Message at 1a001ff [ message=Hello World ]
> FIRED DIFFERENT:
> $f1 = com.sample.DroolsTest$Message at 1a001ff [ message=Hello World ]
> $f2 = com.sample.DroolsTest$Message at 1c6572b [ message=Hello Bob ]
>
> []s
> Edson
>
>
>
> 2007/11/14, Sikkandar Nawabjan <Sikkandar.Nawabjan at ust-global.com>:
>
> i just use this sort of rule
>
> rule "Hello World"
>
> dialect "mvel"
>
> when
>
> m : Message( $message1 : message )
>
> mdup : Message($message2:message==$message1,eval(this!=m) )
>
> then
>
> System.out.println("Rule Fired1111"+m +"::"+mdup );
>
> System.out.println ("Rule Fired"+$message1 +"::"+$message2 );
>
> end
>
>
>
> if i put rule parameter dialect "MVEL" the error "this should be
> used in static context" is gone. But now the rule is firing whatever may be
> the data
>
> i assert 2 objects with message Hello and Hello11111.
>
> still the rule is firing(2 times).
>
> Thanks and regs,
>
> basha
>
>
>
>
> Message: 1
> Date: Wed, 14 Nov 2007 09:48:02 -0200
> From: "Edson Tirelli" < tirelli at post.com>
> Subject: Re: [rules-users] RE: how to find duplicate inlineeval
> To: "Rules Users List" <rules-users at lists.jboss.org >
> Message-ID:
> <
> e6dd5ba30711140348p6da77e64kdac90cd313b5aa80 at mail.gmail.com>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Sorry, you lost me. What is the error message?
> Can you send us a self contained test showing the problem you
> are having?
>
> []s
> Edson
>
> 2007/11/14, Sikkandar Nawabjan < Sikkandar.Nawabjan at ust-global.com<mailto:
> Sikkandar.Nawabjan at ust-global.com> >:
> >
> > Edson,
> >
> > As you said i used inline eval. But am getting erroe message
> like this
> > can't be used in static context.am <http://context.am/> using
> statelesssession to assert my
> > objects.
> >
> > i also put eval(this!=obj1) as follows.
> >
> > $obj1:Object1($id:id,$name:name)
> > $obj2:Object1(id==$id,$name:name==$name, eval( this!=$obj1
> > )) eval($obj2!= $obj1)
> >
> > Though my references are different the rule is not firing
> >
> >
> > Thanks and Regs
> >
> > Basha
> >
> > From: rules-users-bounces at lists.jboss.org on behalf of Edson
> Tirelli
> > Sent: Tue 11/13/2007 9:35 PM
> > To: Rules Users List
> > Subject: Re: [rules-users] RE: how to find duplicate
> >
> >
> >
> >
> > Sikkandar,
> >
> > The only way to check for identity is to use an inline eval
> and use
> > java code to check that:
> >
> > when
> > $obj1:Object1($id:id,$name:name)
> > $obj2:Object1(id==$id,$name:name==$name, eval(
> this!=$obj1 ))
> > then
> >
> > Another option is to configure your rulebase to not allow the
> same
> > object to be matched by more than one pattern in your rules. To
> do that you
> > can either set a system property:
> >
> > drools.removeIdentities = true
> >
> > Or you can use drools API:
> >
> > RuleBaseConfiguration conf = new RuleBaseConfiguration();
> > conf.setRemoveIdentities( true );
> > RuleBase rulebase = RuleBaseFactory.newRuleBase( conf );
> >
> > If you do that, your rule can be written as this:
> >
> > when
> > $obj1:Object1($id:id,$name:name)
> > $obj2:Object1(id==$id,$name:name==$name)
> > then
> >
> > Since the engine will never allow the same fact to
> simultaneously match
> > both patterns.
> >
> > []s
> > Edson
>
>
>
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>
>
>
>
>
>
> --
> Edson Tirelli
> Software Engineer - JBoss Rules Core Developer
> Office: +55 11 3529-6000
> Mobile: +55 11 9287-5646
> JBoss, a division of Red
>
>
> _______________________________________________
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>
>
>
--
Edson Tirelli
Software Engineer - JBoss Rules Core Developer
Office: +55 11 3529-6000
Mobile: +55 11 9287-5646
JBoss, a division of Red Hat @ www.jboss.com
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