Hi Gurvinder.
Not sure where new lines have gone from your email – it makes it very hard to read!
I’ve also been working on a project which uses decision tables and I couldn’t find any way to use from statements either. I’m hoping to get some time within
the project to work on the drools decision table code to add some improvements, providing support for the from clause is one of these however I’m not sure whether I will get time or not.
However I think you may be able to restructure your code so that you don’t need the from cause however I’ve not fully tested it. The code relies on their
existing a constructor which takes the promotion code and the equals is defined that P1.equals(P2) when P1.code.equals(P2.code).
If you wanted to match that a promotion of a particular name exists then I think you can use the rule
Rule “existsPromotion” when
Line(promos contains (new Promotion("HOTBUY"))) then ...
However the expression language doesn’t support “not contains” which means you have to full back to use java:
rule " contains d"
when
line : Line(eval(!line.getPromos().contains(new Promotion("HOTBUY"))))
then
...
end
If you prefer you could also define a method on Line containsPromotionWithCode(code) which would let you choose how to do the match.
As a spreadsheet the above would then look something like the following:
|
RuleTable Hotbuys |
|
|
|
NAME |
CONDITION |
ACTION |
|
|
l :Line |
|
|
|
eval(!l.getPromos().contains(new Promotion("$param"))) |
System.out.println("$param"); |
|
Rule Name |
Number Directors |
Warning |
|
example1 |
Hotbuys |
Hotbuys missing |
Hope that helps,
Thomas
From: rules-users-bounces@lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org]
On Behalf Of groovenarula
Sent: 03 December 2009 06:51
To: rules-users@lists.jboss.org
Subject: [rules-users] Can we use 'from' CE in Decision Tables ?
Hello all, Is it possible to define the follow rule in a decision table : rule "Activate Promotion" when l : Line( ) not ( Promotion ( code == "HOTBUY" ) from l.promos ) then #do some action end The rule above works perfectly for what I
need when defined in a rule file. However, when I try to define it in a decision table so that the 'code' can be feed from a spreadsheet, I use the following values in the rules cells : RuleTable HOTBUYS CONDITION ACTION l : Line not ( Promotion ( code ==
"$param" ) from l.promos ) System.out.println("$param added"); PROMOTION PROMOTION HOTBUY BESTBUY I'm getting the following parser errors [10,17]: [ERR 101] Line 10:17 no viable alternative at input 'Promotion' in rule "_11" in pattern Line [10,29]: [ERR 101]
Line 10:29 no viable alternative at input 'code' in rule "_11" [10,63]: [ERR 102] Line 10:63 mismatched input ')' expecting 'then' in rule "_11" java.lang.IllegalArgumentException: Could not parse knowledge. at com.sample.DecisionTableTest.readKnowledgeBase(DecisionTableTest.java:85)
at com.sample.DecisionTableTest.main(DecisionTableTest.java:28) Also in Eclipse IDE, I get the following error : "Unknown error while parsing. This is a bug. Please contact the Development team." NewPromotions.xls Is it possible to use 'from' conditional element
in decision tables ? If so, what am I doing wrong. If not, then what's the best approach to implement the rule above in a decision table. I'm running Drools 5.1.0M1 in Eclipse. Help truly appreciated. Gurvinder
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Can we use 'from' CE in Decision Tables ?
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