property.js is a JavaScript Library that Provides Simpler Usage of the Native Properties (as specified in ECMAScript 5, see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/defineProperty for browser support).

• Create properties in a simple way
• Observe changes to the properties
• Use privacy for separation of concern

	var HiSayer = function(){
		property.mixin(this);
		
		this.addProperty("phrase", "hello, my name is");
		this.addProperty("name", "Roberto");
		this.addProperty("greeting").
			getter(function(){ return this.phrase + " " + this.name; }).
			setter(false);
	}

	var hiSayer = new HiSayer();

	console.log(hiSayer.greeting); //console: hello, my name is Roberto
	hiSayer.name = "Alejandro";
	console.log(hiSayer.greeting); //console: hello, my name is Alejandro

	var HiSayer = function(){
		property.mixin(this);
		this.addProperty("phrase", "hello, my name is");
		this.addProperty("name", "Roberto").observe(function(newVal, oldVal){
			console.log("Did you just change name from " + oldVal + " to " + newVal + "?")
		});
	}

	var hiSayer = new HiSayer();

	hiSayer.name = "Alejandro"; //console: Did you just change name from Roberto to Alejandro?

	var HiSayer = function(){
		property.mixin(this);	
		var phrase 		= this.addProperty("phrase", "hello, my name is"),
			name 		= this.addProperty("name", "Roberto").setter(true, true), //second argument specifies that setter is private
			greeting 	= this.addProperty().
				getter(function(){ return this.phrase + " " + this.name; }, true).
				setter(false);

		name("Alejandro"); //Use the private handle to set, this uses same syntax as ex. JQuery Properties
		console.log(greeting()); //Use the private handle to get!
	}

	var hiSayer = new HiSayer();

	console.log(hiSayer.greeting); //Undefined because property is fully private
	hiSayer.name = "Alejandro"; //throws error: Attempt to change private setter publicly

	var HiSayer = function(){
		property(this, "phrase", "hello world");
		console.log(this.phrase);	
	}

The Getters and Setters are powerful, and allows you to use the properties in a flexible manner:

• The first argument allows you to specify a custom Getter/Setter Method, or alternatively a truthy value to use the default Method (directly getting and setting the internal value of the property), or a falsy value to remove the Getter/Setter completely. Both getters and setters are expected to return a value, for the setter this is the value that's gonna get stored internally.
• The second argument specifies whether the Property is private or not (public is default). A private Setter/Getter is only accessable from the private property handle (which is the variable returned from addProperty), whereas a public Setter/Getter will be available as a property on the object.