jQuery UI DateTime extensions

UiExtensions.js

var App = { namespace: 'foo' };

(function (factory) {
    'use strict';
    if (typeof define === 'function' && define.amd) {
        // Register as an anonymous AMD module:
        define([
            'jquery'
            , 'jqueryui' 
            , App
        ], factory);
    } else {
        // Browser globals:
        factory(window.jQuery, window.jQuery.ui, App || {});
    }
}(function ($, ui, App) {
    'use strict';
  
	App.UiExtensions = function(options) {
		if (!(this instanceof App.UiExtensions))
			throw new Error('Constructor invoked as a function!');

    if (typeof $ === undefined)
      throw new Error('The following dependency was not satisfied: jQuery');
      
    if (typeof $.ui === undefined)
      throw new Error('The following dependency was not satisfied: jQuery.ui');

		this.defaults = {  
      dateTimeSelector: 'input.datetime:not(.hasDatepicker)'
      , zIndex: 200
      , dateFormat: 'dd/mm/yy'
      , changeMonth: true
      , changeYear: true
      , maxDate: 0
      , minDate: new Date(1970, 0, 1)
      , yearRange: '-40:+0'
		};

		this.settings = $.extend({}, this.defaults, options);
	};
	
	App.UiExtensions.prototype = function() {
		return {
			initDatePicker: function () {
				var self = this
					, zIndex = self.settings.zIndex
					, dateFormat = self.settings.dateFormat
					, changeMonth = self.settings.changeMonth
					, changeYear = self.settings.changeYear
					, maxDate = self.settings.maxDate
					, minDate = self.settings.minDate
					, yearRange = self.settings.yearRange;

				$(document).on('focus', this.settings.dateTimeSelector, function (event) {
					$(this).datepicker({
						dateFormat: dateFormat,
						changeMonth: changeMonth,
						changeYear: changeYear,
						maxDate: maxDate,
						minDate: minDate,
						yearRange: yearRange,
						onSelect: function () { $(this).valid(); }
					}).css('z-index', zIndex);

					// fix for ie8 whereby the datepicker div is not hidden
					//setTimeout(function () { $(".ui-datepicker").hide(); }, 20);
				});
			}
		};
	}();
}));