Interface HelperAdapter

All Known Implementing Classes:
InterpretedHelper

public interface HelperAdapter
This interface defines the methods which need to be added to a helper class in order for it to plug in to the rule system. In the case of the default helper class, Helper, this interface is implemented by a pre-defined subclass, InterpretedHelper which interprets the rule parse tree. Given any user-supplied helper class the rule compiler can generate a HelperAdapter class which interprets the rule tree and invokes builtin methods using reflection. The compiler can also generate a HelperAdapter whose bind(), test() and fire() methods are compiled from bytecode derived from the parse trees of, respectively, the rule's event, condition and action. Bytecode compilation is applicable to rules which employ the default helper as well as rules which employ user-defined helpers.