theluk / BaseJs-Extended

Extended version of John Resig's Base.js for supporting getters and setters

Base.js Extended - Supporting JavaScripts getters and setters

I was working with Base.js (by John Resig) for a while and now I used it in Appcelerators Mobile Framework. I realised they support setting the properties getters and setters.

I then found Johns post http://ejohn.org/blog/javascript-getters-and-setters/ where he describes the syntax and possible implementations when you want to extend objects.

So I decided to mix it in Base.js

Usage of BaseEx.js

First You should know how to use John Resigs Base.js, details here: http://ejohn.org/blog/simple-javascript-inheritance/

var Person = Class.extend({
	init: function(options) {
		this.firstName = options.firstName;
		this.lastName = options.lastName;
	},
	get fullname() {
		return this.firstName + " " + this.lastName;
	},
	get message() {
		return "Person: " + this.fullname;
	}
});

var Employee = Person.extend({
	init: function(options) {
		this._super();
		this.department = options.department;
	},
	get message() {
		return this._super() + " Department: " + this.department;
	}
});

var person = new Person({
	firstName : "Mike",
	lastName : "Miller"
});

console.log(person.message);
//--> Person: Mike Miller

var employee = new Employee({
	firstName : "Mike",
	lastName: "Miller",
	department: "Sales"
});

console.log(employee.message);
//--> Person: Mike Miller Department: Sales

Additional Functionality

Class.override method

This helps to override getters and setters or functions on your prototype "override" can set new methods or getters/setter too.

"override" accepts 2 arguments, "name" and ("obj" or "fn"). if you specify an object with "get" or/and "set" then this override will delegate to the getters and setters. if you dont specify an object but a function just the function will be set onto the prototype. Both possibilities give you always the possibility to use the _super method/function.

var Person = Class.extend({});

var p, properties = "firstname lastname address".split(" ");

while((p = properties.shift())) {
	Person.override(p, {
		get : function() {
			return this["_" + p];
		},
		set : function(value) {
			this["_" + p] = value;
			// this needs some event provider
			this.trigger("Property " + p + " changed...";
		}
	});
}

var person = new Person();
person.firstname = "Mike";
//--> triggers "Property firstname changed..." (if some event provider implemented)