Introduction to cloj-rules-engine

cloj-rules-engine is a very simple rules engine written in Clojure and designed to work with Java.

Features:

• Each rule has a condition (composed of conditional expressions -written in Clojure- that refer to facts), and a set of actions that are activated if the condition is satisfied. Facts are the data upon which rules operate. The fired actions are a represented as a set of identifiers (strings).

• Rules are expressed in a simple and easy to read Clojure format (clojure maps)

{
  :RULE_1 {:cond "(and (< #A 10) (> #B 50))"
           :actions ["action-1"]}
  ...
}

• Facts can be expressed via clojure maps (Clojure) or via PersistentArrayMap objects (Java):

(update-map-facts {"#A" "14"})

PersistentArrayMap facts_map = new PersistentArrayMap(new Object[] {
		"#A", "14"
	});
clrules.updateMapFacts(facts_map);

• This library can be used from Java or Clojure code

• Third party libraries used in this project:

Libs	Version	License
clojure	1.8.0
tools.logging	0.3.1
log4j	1.2.17
data.json	0.2.6
proto-repl	0.3.1
math.numeric-tower	0.0.4

• Main methods:

  • initialize loads rules map from absolute or relative path. Returns true if everything is okay.

  (initialize "rules.clj")
  

  clrules.initialize("rules.clj");
  

  • update-map-facts update / initialize facts

  (update-map-facts {"#A" "14"})
  

  clrules.updateMapFacts(facts_map);
  

  • get-rules-actions evaluates rules based on current facts, and return a list (String) of 'fired' actions

  (get-rules-actions)
  

  clrules.getRulesActions();
  

  • get-fired-rules

  • initialize-from-json