Terminalogies

Rule unit

• a class that implements RuleUnitData
• which groups data sources, global variables and DRL rules
  • DataStore<UserDefinedInputClass> --> data sources
    • An UserDefinedInputClass object is called a Fact
  • Any variable within the class
• a new and recommended style for implementing rules in Drools 8

Data sources

• strongly typed sources of data that rule units can subscribe to for updates
• 2 kinds:
  • DataStream: append-only
  • DataStore: writable (adding/removing then notify all subscriberss)
  • SingletonStore: A writable storage option for setting or clearing a single element and then notifying all subscribers that the element has been modified. Works as global var
• DataSources can be shared across different units

Data processors

• subscribers to a data source
• implements DataProcessor<T> as event handlers

KieBase

• a repository of all the application’s knowledge definitions
• it contains rules, processes, functions, and type models
• itself does not contain data; instead, sessions are created from the KieBase into which data can be inserted and from which process instances may be started

KieSession

• it stores and executes on the runtime data
• created from KieBase

default KieSession

• An empty kmodule.xml will produce a single (default) KieBase that includes all files found under resources path
• Default means they can be created without knowing their names.
• vs Named KieSession defined in kmodule.xml

KieRuntime

• it provides methods that are applicable to both rules and processes, such as setting globals and registering channels