Question

This should be simple, but I am still lost.
There is a very similar post here: How to share data between Drools rules in a map?
but it doesn’t fix my problem:

I have a set of rules and, before launching them, I insert a Map<String, Object> as a fact.
In these rules I use the map to write some conclusions like:

when
   $map : Map();
   something ocurrs;
then
   $map.put("conclusion1", 100);

Now I would like to use these intermediate conclusions in other rules, something like:

when
   $map : Map(this["conclusion1"] > 50)
then
   do something cool;

The problem is that when I execute the rules it is like the second rule doesn’t see the conclusions of the first one, and it does not fire.
I have tried putting a break point and analysing the working memory, and, in fact, the Map would contain the conclusion1, 100 after the first rule is fired.
I have also tried by making an update($map) in the conclusion, but that would trigger an infinite loop.

Any idea of why this wouldn’t work, or any alternative solution to my problem?

Thanks !

Answer 1

When you modify a fact you need to notify the engine you are doing so. One of the ways of doing that is by using modify(). E.g.:

when
   $map : Map();
   something ocurrs;
then
   modify( $map ) { 
      put("conclusion1", 100)
   }
end