requirejs amd module load example

/** * This example make use of requireJS to provide a clean and simple way to split JavaScript class definitions * into separate files and avoid global namespace pollution. ?http://requirejs.org/ * * We start by defining the definition within the require block inside a function; this means that any * new variables / methods will not be added to the global namespace; requireJS simply requires us to return * a single value (function / Object) which represents this definition. ?In our case, we will be returning * the Class‘ function. */define(function () { ???// Forces the JavaScript engine into strict mode: http://tinyurl.com/2dondlh ???"use strict"; ???/** ????* This is our classes constructor; unlike AS3 this is where we define our member properties (fields). ????* To differentiate constructor functions from regular functions, by convention we start the function ?????* name with a capital letter. ?This informs users that they must invoke the Person function using ????* the `new` keyword and treat it as a constructor (ie: it returns a new instance of the Class). ????*/ ???function Person(name) { ???????// This first guard ensures that the callee has invoked our Class‘ constructor function ???????// with the `new` keyword - failure to do this will result in the `this` keyword referring ????????// to the callee‘s scope (typically the window global) which will result in the following fields ???????// (name and _age) leaking into the global namespace and not being set on this object. ???????if (!(this instanceof Person)) { ???????????throw new TypeError("Person constructor cannot be called as a function."); ???????} ???????// Here we create a member property (field) for the Person‘s name; setting its value ???????// what the one supplied to the Constructor. ?Although we don‘t have to define ???????// properties ahead of time (they can easily be added at runtime as all Object / functions ????????// in JavaScript are dynamic) I believe it makes your code easier to follow if you list your ???????// classes intentions up front (eg: in the Constructor function). ???????this.name = name; ???????// Here we are defining a private member. As there is no `private` keyword in JavaScript ???????// there is no way for us to hide this data (without resorting to inelegant hacks); instead ???????// we choose to use a naming convention where a leading underscore indicates a property ???????// is private and should not be relied upon as part of the Classes public API. ???????this._age = -1; ???} ???/** ????* Adding static properties is as simple as adding them directly to the constructor ????* function directly. ????*/ ???Person.RETIREMENT_AGE = 60; ???/** ????* Public Static methods are defined in the same way; here‘s a static constructor for our Person class ????* which also sets the person‘s age. ????*/ ???Person.create = function (name, age) { ???????var result = new Person(name); ???????result.setAge(age); ???????return result; ???}; ???/** ????* Any functions not added to the Person reference won‘t be visible, or accessible outside of ????* this file (closure); however, these methods and functions don‘t belong to the Person class either ????* and are static as a result. ????*/ ???function formatNameAndAge(person) { ???????// Note that `this` does not refer to the Person object from inside this method. ???????if (person._age === -1) { ???????????return "We don‘t know how old " + person.name + " is!"; ???????} ???????return (person.name + ", is " + person._age + " years old and " ???????????+ ((person.canRetire()) ? "can" : "can‘t") + " retire"); ???}; ???/** ????* The prototype is a special type of Object which is used as a the blueprint for all instances ????* of a given Class; by defining functions and properties on the prototype we reduce memory ????* overhead. ?We can also achieve inheritance by pointing one classes‘ prototype at another, for ????* example, if we introduced a BankManager class which extended our Person class, we could write: ????* ????*`BankManager.prototype = Person.prototype` ????*`BankManager.prototype.constructor = BankManager` ????* ????* However, due to the dynamic nature of JavaScript I am of the opinion that favouring composition ????* over inheritance will make your code easier to read and re-use. ????*/ ???Person.prototype = { ???????/** ????* Whenever you replace an Object‘s Prototype, you need to repoint ????* the base Constructor back at the original constructor Function, ?????* otherwise `instanceof` calls will fail. ????*/ ???constructor: Person, ???????????/** ????????* All methods added to a Class‘ prototype are public (visible); they are able to ?????????* access the properties and methods of the Person class via the `this` keyword. ?Note that ????????* unlike ActionScript, usage of the `this` keyword is required, failure to use it will ?????????* result in the JavaScript engine trying to resolve the definition on the global object. ????????*/ ???????greet: function () { ???????????// Note we have to use the `this` keyword. ???????????return "Hello, " + this.name; ???????}, ???????/** ????????* Even tho the `_age` property is accessible; it still makes a lot of sense to provide ????????* mutator methods (getters / setters) which make up the public API of a Class - here we ????????* validate the supplied value; something you can‘t do when a field is modified directly ????????*/ ???????setAge: function (value) { ???????????// Ensure the supplied value is numeric. ???????????if (typeof (value) !== ‘number‘) { ???????????????throw new TypeError(typeof (value) + " is not a number."); ???????????} ???????????// Ensure the supplied value is valid. ???????????if (isNaN(value) || value < 0) { ???????????????throw new RangeError("Supplied value is out of range."); ???????????} ???????????this._age = value; ???????}, ???????/** ????????* This method access both a member property and a static property. ????????*/ ???????canRetire: function() { ???????????return this._age >= Person.RETIREMENT_AGE; ???????}, ???????/** ????????* Finally we can also access ‘static‘ functions and properties. ????????*/ ???????toString: function() { ???????????// Note that as `formatNameAndAge` is static we must supply a reference ???????????// to `this` so it can operate on this instance. ???????????return formatNameAndAge(this); ???????} ???}; ???// As mentioned up top, requireJS needs us to return a value - in this files case, we will return ???// a reference to the constructor function. ???return Person;});

 ???require([‘site‘],function(Person){ ???????var jonny = new Person("Jonny"); ???????jonny.setAge(29); ???????console.log(jonny.toString()); ???});