Create YUI3 Module For Moodle

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Please see How to create a YUI 3 module for more up to date information.

Introduction

The flexibility of JavaScript is potential for good or evil. For one side, it enables you to write really smart code, for another side, it could decrease the readability of your source code, for complex project like Moodle, readability is an essential factor to write code.

Since we introduce YUI3 in moodle 2.0, the use of JavaScript in Moodle has been improved a lot. We are creating more and more YUI3 modules to replace previous all-in-one javascript-static.js to make JavaScipt Scalable. It is time to have a standard way to create YUI3 modules for Moodle. So I wrote this proposal for further development, feel free to comment/change this page.

Methods

The YUI3 recommended way

Registering and defining a module by YUI3 method.

NOTE: It is not necessary to use Y.filepicker here, we can also register to M.filepicker

Sample code

YUI.add('filepicker', function(Y) {
    var filepicker = function(args) {
        filepicker.superclass.constructor.apply(this, arguments);
    }
    filepicker.NAME = "MoodleFilePicker";
    Y.extend(filepicker, Y.Base, {
        initializer: function(args) {
        }
    });
    Y.filepicker = filepicker;
}, '3.0.1', {requires: ['io', 'node', 'event']});

To use this module:

Y.use('filepicker', function(Y) {
    var fp = new Y.filepicker({});
});

Pros

• No Global Namespace Pollution
• YUI3 standard way to create modules

Cons

• Maybe incompatible with future YUI4

Use anonymous function

Sample code

M.filepicker = (function() {
    var filepicker = function(args) {
        filepicker.superclass.constructor.apply(this, arguments);
    }
    filepicker.NAME = "MoodleFilePicker";
    Y.extend(filepicker, Y.Base, {
        initializer: function(args) {
        }
    });
    return filepicker;
})();

To use this module:

Y.use('filepicker', function(Y) {
    var fp = new M.filepicker({});
});

Pros

• No Global Namespace Pollution

Use init() method

Sample code

M.filepicker = {
    init: function(args) {
        var filepicker = function(args) {
            filepicker.superclass.constructor.apply(this, arguments);
        }
        filepicker.NAME = "MoodleFilePicker";
        Y.extend(filepicker, Y.Base, {
            initializer: function(args) {
                // initialize object
            }
        });
        new filepicker;
    }
};

To use this module:

Y.use('filepicker', function(Y) {
    M.filepicker.init({});
});

Pros

• No Global Namespace Pollution

Cons

• Not quite OOP

Use M.core_modulename as namespace and add module related static methods and class to it

Sample code

M.core_filepicker = {};

// define a class
M.core_filepicker.ui = function() {
    this.classname = '';
}
M.core_filepicker.prototype.instancemethod = function() {
}
//static method
M.core_filepicker.init = function() {
    new M.core_filepicker.ui();
}

Reference

• How to create a YUI 3 module
• Building YUI 3 Custom Modules
• Scalable JavaScript Application Architecture
• Migrating to YUI3, filepicker, filemanager, comment and form