Thanks for your reply Greg. Actually I have 2 requirements:
1) Define the data objects in the rule itself so that the business user can define\modify the data objects 2) have a rule that can evalaute the data objects against the criteria the user requests.. It is my bad I started with the 2nd requirement :( Regards, cabear On Wed, Nov 11, 2009 at 1:50 PM, Greg Barton <[email protected]> wrote: > Funny you should bring that up, I was just having this debate with a > co-worker. :) > > A decision table is a means for defining rules, not working memory objects. > So no, out of the box a decision table as it's defined in drools (and other > rule management systems) would not serve that purpose. However, there's no > reason why you couldn't parse a spreadsheet (or other tabular data format) > to generate Data objects. > > Now, are you sure it's Data objects you want to generate? I'm guessing > from how your question was phrased that it's Query objects you'd like to > generate. In that case the answer to the question is still no, but...if you > use Wolfgang's approach to solve the problem (i.e. defining the queries in > the rules themselves, and not in a working memory object) then using a > decision table is appropriate. In fact, it's probably the best way to > define the rules. (It's most compact and readable when you have many rules > with a repetitive structure.) > > --- On Wed, 11/11/09, Wishing Carebear <[email protected]> wrote: > > > From: Wishing Carebear <[email protected]> > > Subject: Re: [rules-users] some pointers for solution > > To: "Rules Users List" <[email protected]> > > Date: Wednesday, November 11, 2009, 3:38 PM > > Hi Greg: > > Is it possible to use decision table to populate the > > Data object that contains the criteria list > > information. > > > > Thanks, > > Ravi > > > > > > 2009/11/8 Greg Barton <[email protected]> > > > > 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 <[email protected]> > > wrote: > > > > > From: Wishing Carebear <[email protected]> > > > > > Subject: [rules-users] some pointers for solution > > > To: [email protected] > > > 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 > > > [email protected] > > > https://lists.jboss.org/mailman/listinfo/rules-users > > > > > > > > > > > > > _______________________________________________ > > rules-users mailing list > > [email protected] > > https://lists.jboss.org/mailman/listinfo/rules-users > > > > > > > > > > > > -----Inline Attachment Follows----- > > > > _______________________________________________ > > rules-users mailing list > > [email protected] > > https://lists.jboss.org/mailman/listinfo/rules-users > > > > > > > _______________________________________________ > rules-users mailing list > [email protected] > https://lists.jboss.org/mailman/listinfo/rules-users >
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