[rules-users] Rule does not fire after 'Modify/Update' of a fact - Drools 5.1.1 !

[groovenarula]

Hello all,

For some reason I have a rule that does not fire after a Modify/Update.

I have 2 facts - Product and Option. The relationship between them is that a
'Product' can have 0 - N 'Option'(s).

Based on that, I added a 'product' field to the 'Option' object. I'm
creating and inserting my facts 
using the following code :

			Product prod = new Product ("001","002", "A");
			prod.setPrice(new BigDecimal("300.00"));
			Option opt = new Option ("H1","",prod);
		
			ksession.insert(prod);
			ksession.insert(opt);
		

Now in my .DLR, I have the following rule :

rule "Set Options price"
	salience 50

	when

		$prod : Product ( price != null )
		$option : Option ( product == $prod ) 

	then
		
		System.out.println( "Getting Options " + $prod ); 
		
end

This gives me the correct output in the console :

  Getting Options Product [category=001, grade=A, price=300.00, style=002]

The rule fired successfully.

I start running into problems when I try to update the 'price' field using a
rule, instead of through code. 

So for example, if I have the following rule also defined in the same drl
file : 

rule "Set price"
	salience 500

	when

		$prod : Product ( category == "001", price == null )

	then

		$prod.setPrice ( new BigDecimal ( "300.00" ) );
		update( $prod );
		System.out.println( $prod ); 
		
end

And then change my code as follows (remove the setPrice call) :

 		Product prod = new Product ("001","002", "A");
		Option opt = new Option ("H1","",prod);
		
		ksession.insert(prod);
		ksession.insert(opt);

I only get the following output :

Product [category=001, grade=A, price=300.00, style=002]

What am I missing here ? I thought the rule 'Set Price' should update the
product fact with 
the new price and the rules would get re-evaluated. After the re-evaluation,
the LHS of 'Set Options Price' should now be true and it should have fired.
But it does not. 

Am I mis-understanding something about activation here ? If I am, can
someone please help explain what the gap is and how to re-write the rules so
that I can achieve the above objective ?

Any help will be appreciated. I've spend several hours trying different
permutations and combinations and got no where.
 
Thanks
Gurvinder


--
View this message in context: http://drools-java-rules-engine.46999.n3.nabble.com/Rule-does-not-fire-after-Modify-Update-of-a-fact-Drools-5-1-1-tp2778508p2778508.html
Sent from the Drools - User mailing list archive at Nabble.com.