13.30. The Conditional Element accumulate and Pluggability

Accumulate functions are all pluggable. That means that if needed, custom, domain specific functions can easily be added to the engine and rules can start to use them without any restrictions. To implement a new Accumulate Function all one needs to do is to create a Java class that implements the org.drools.runtime.rule.TypedAccumulateFunction interface and add a line to the configuration file or set a system property to let the engine know about the new function.