[rules-users] some pointers for solution
Wishing Carebear
wishing.carebear at gmail.com
Sun Nov 8 21:02:15 EST 2009
Yes Edson, I tried with count and sum. Both seems to be working fine.
But with the test case, the Criteria for query also needs to be inserted in
addition to the query and data objects like shown below:
Query query = *new* Query(1);
query.add(*new* Criteria(query, "c2", "bas"));
ksession.insert(query);
*for*(Criteria c : query) {
ksession.insert(c);
}
Is it possible to avoid them.
Thanks,
cabear
2009/11/8 Edson Tirelli <ed.tirelli at gmail.com>
>
> Why not use count() accumulate function? ;)
>
>
> from accumulate( Criteria( this memberOf d, this memberOf q ),
> count(1) )
>
> Edson
>
>
> 2009/11/8 Greg Barton <greg_barton at yahoo.com>
>
>> In this case the accumulate clause is maintaining a counter (total) that's
>> incremented whenever a Criteria is detected that is contained in both the
>> Data and Query object matched in the rule. So:
>>
>> # Find Criteria that are contained in both the Data and Query
>> from accumulate( Criteria( this memberOf d, this memberOf q ),
>> # Initialize the counter to 0
>> init( int total = 0; ),
>> # Increment when the above condition is matched
>> action( total ++; ),
>> # Decrement if a matched Criteria now fails to match
>> reverse( total --; ),
>> # return the total when all known Criteria are matched
>> result( total ) )
>>
>> --- On Sun, 11/8/09, Wishing Carebear <wishing.carebear at gmail.com> wrote:
>>
>> > From: Wishing Carebear <wishing.carebear at gmail.com>
>> > Subject: Re: [rules-users] some pointers for solution
>> > To: "Rules Users List" <rules-users at lists.jboss.org>
>> > Date: Sunday, November 8, 2009, 11:39 AM
>> > Hi Greg:
>> > I'm trying to understand your first
>> > solution.
>> >
>> > Ran the project and it works fine. If possible could
>> > you explain me little bit on :
>> >
>> > from accumulate( Criteria( this memberOf d,
>> > this memberOf q ),
>> > init( int total = 0; ),
>> > action( total ++; ),
>> > reverse( total --; ),
>> > result( total ) )
>> >
>> >
>> > Thanks,
>> > cabear
>> >
>> >
>> > 2009/11/8 Greg Barton <greg_barton at yahoo.com>
>> >
>> > There are a couple of
>> > ways to do this. I'm sure there's a bit more clean
>> > way than the example I'm providing, but this should get
>> > you in the right direction. It's not 100% rules,
>> > because it involves a bit of java collections trickery. (See
>> > attached project, collection_DroolsCriteriaMatch.tar.gz)
>> >
>> >
>> > The heart of it is a single rule:
>> >
>> > rule "Match"
>> > when
>> > d : Data()
>> > q : Query( size <= d.size )
>> > Number( intValue == q.size )
>> > from accumulate(
>> > Criteria( this memberOf d, this memberOf q ),
>> >
>> > init( int total = 0; ),
>> > action( total ++; ),
>> > reverse( total --; ),
>> > result( total )
>> > )
>> > then
>> > System.out.println("Match: " + d + "
>> > and " + q) ;
>> > end
>> >
>> > The Data object holds data to be queried, Query objects are
>> > asserted to match the Data, and Criteria objects can be
>> > contained in either. (With the aforementioned collections
>> > trickery that if a Criteria is contained in a Query it can
>> > be found in a Data object, but the reverse isn't true.
>> > See the Query.contains(Object) method for how that's
>> > implemented.)
>> >
>> >
>> > So the rule above basically says "There's a Data
>> > object, and all of the Query objects Criteria are contained
>> > in the Data object."
>> >
>> > There's an alternate way of doing this using eval and a
>> > bit more java fu. See the eval_DroolsCriteriaMatch.tar.gz
>> > project attached. This one's probably not optimal,
>> > though, as it's basically a brute force check of all
>> > Data objects against the asserted Query.
>> >
>> >
>> > I tried for a while to get a solution working with
>> > different criteria types from both Data and Query objects
>> > being asserted into working memory, but I couldn't get
>> > the accumulate syntax right. Anyone know of a way to do
>> > that? (I figure that would get a "pure rules"
>> > solution.)
>> >
>> >
>> > --- On Sat, 11/7/09, Wishing Carebear <wishing.carebear at gmail.com>
>> > wrote:
>> >
>> > > From: Wishing Carebear <wishing.carebear at gmail.com>
>> >
>> > > Subject: [rules-users] some pointers for solution
>> > > To: rules-users at lists.jboss.org
>> > > Date: Saturday, November 7, 2009, 10:19 PM
>> >
>> >
>> >
>> > > Hello:
>> > > There are n selection criteria from s1 .. sn for each
>> > > item i1.. in. Each item can have a subset of criteria
>> > which
>> > > applies to them.
>> > >
>> > > The end user, can choose a subset of criteria like c1
>> >
>> > > and c5 and only the item that has c1 and c5 valid
>> > should be
>> > > returned. For example: if item i1 and i2 have
>> > criterias
>> > > valid for c1, c2, c5, c6, c8 since the request is only
>> > for
>> > > criteria c1 and c5, i1 and i2 must be returned.
>> >
>> > >
>> > >
>> > > Is it possible to write a rule using drools for this
>> > > requirement.
>> > >
>> > > Thanks for your help and time,
>> > > cabear
>> > >
>> > > -----Inline Attachment Follows-----
>> >
>> > >
>> > > _______________________________________________
>> > > rules-users mailing list
>> > > rules-users at lists.jboss.org
>> > > https://lists.jboss.org/mailman/listinfo/rules-users
>> >
>> > >
>> >
>> >
>> >
>> > _______________________________________________
>> > rules-users mailing list
>> > rules-users at lists.jboss.org
>> > https://lists.jboss.org/mailman/listinfo/rules-users
>> >
>> >
>> >
>> >
>> >
>> > -----Inline Attachment Follows-----
>> >
>> > _______________________________________________
>> > rules-users mailing list
>> > rules-users at lists.jboss.org
>> > https://lists.jboss.org/mailman/listinfo/rules-users
>> >
>>
>>
>>
>>
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>>
>
>
>
> --
> Edson Tirelli
> JBoss Drools Core Development
> JBoss by Red Hat @ www.jboss.com
>
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