Defining RuleBooks

RuleBook basics, defineRules(), and the HelloWorld example.

Defining RuleBooks

The preferred approach is to create your own RuleBook that extends rulebox.models.RuleBook, with a method called defineRules(). In this method you define all the rules that apply to that RuleBook using the RuleBox DSL. Nothing stops you from creating rulebooks on the fly either, which lets you build dynamic or à la carte rules when needed - see The Builder.

RuleBooks should be transient objects, since they're reused when bound to facts. See Thread Safety.

A HelloWorld example

class extends="rulebox.models.RuleBook"{

	function defineRules(){
		// Add a new rule to this rulebook
		addRule(
			newRule( "MyRule" )
				.then( ( facts ) => println( "Hello " ) )
				.then( ( facts ) => println( "World" ) )
		)
	}

}

New rules are created by calling newRule() with an optional name you can use to identify the rule later, for auditing. You can also define a rule as a closure/lambda instead, with a slightly different syntax:

class extends="rulebox.models.RuleBook"{

	function defineRules(){
		addRule( ( rule ) => {
			rule
				.setName( "MyRule" )
				.then( ( facts ) => println( "Hello " ) )
				.then( ( facts ) => println( "World" ) )
		} )
	}

}

A RuleBook also has a name property, so you can attach a human-readable name to it via setName( name ).

...or use two separate rules:

class extends="rulebox.models.RuleBook"{

	function defineRules(){
		addRule(
			newRule()
				.then( () => println( "Hello " ) )
		)
		addRule(
			newRule()
				.then( () => println( "World " ) )
		)
	}

}

Now, run it:

getInstance( "HelloWorld" ).run()

Retrieving a RuleBook

Since a RuleBook subclass is just a WireBox-mapped CFC/BX class, you retrieve it the same way you'd retrieve any other transient:

var homeLoans = getInstance( "path.to.HomeLoanRateRuleBook" )