Hello,
I've only been working with Drools for a little over a month or so now and I've
begun integrating it into my application via Eclipse and creating DRL files. The nature
of this application is to take a data record from one file and create a new data record in
another file. This is done in a batch of any number of records, depending on the number
of records sent to us in the first file. To accomplish this I have two classes, one
representing each file, and I create and object for each of them, inserting them into the
knowledge session and then fire the rule.
ksession.insert(myObjectIn);
ksession.insert(myObjectOut);
ksession.fireAllRules();
The first object has around 1,000 fields and the second has 250, so my class structure is
quite broad.
In a DRL file I have created the following rule:
rule "Primary Diagnosis Code"
when
$ccl : anObjectIn(IncomingDiag1 != null)
$cdl : anObjectOut()
then
$cdl.PrimaryDiag = $ccl.IncomingDiag1;
end
This rule fires great and the PrimaryDiag field in myObjectOut is updated with what iss in
myObjectIn.IncomingDiag. I can then write the object back out the the database fine.
A requirement of my project is that I allow users (analysts) to create their own rules
that are above and beyond those I might create in a .drl file. To do so we are looking to
deploy Guvnor and let them use the Guided editor to create rules. I've already loaded
my fact models into Guvnor and have them available in the drop down conditions.
The questions that are hitting me now are:
1) On the LHS when I've chosen the fiels IncomingDiag the only options I have for
conditions are "equal to", "not equal to", "matches", and
"sounds like". I don't see an option for null or notnull. If I were to
choose "not equal to" I then have the options for Literal Values, New Formulas,
or Expression Editor (which has none by default). I haven't seen any examples where
someone is evaluating a field in Guvnor for being either "" or null. How would
one accomplish this? The literal value does not allow you to leave it blank as in
"" and if you type "" in it, the source shows
"""".
2) On the LHS, if I were to want to evaluate IncomingDiag1 == IncomingDiag2 I
don't see a method except if I were to choose New Formula and type in the field name
Incoming Diag2. Is there another way that they could be prompted for the field choises
again?
3) On the RHS, when I go to add a new then, I'm prompted to choose only to either
"insert fact anObjectIn" or to "logically insert fact anObjectIn" or
to manually enter DRL logic. Both of the inserts appear to create logic that would create
a new object with the data in it:
anObjectIn fact0 = new anObjectIn ();
fact0. IncomingDiag1 ( 11 );
insertLogical(fact0 );
But what I really want is something similar to my DRL from above. Am I missing
something? Or would this have to be a case where they would manually enter the DRL
statement?
Thank you!
Dean Whisnant
Senior Software Developer
basys, inc.