source: Dev/trunk/src/client/dojox/form/MonthTextBox.js

define([
        "dojo/_base/kernel",
        "dojo/_base/lang",
        "dojox/widget/MonthlyCalendar",
        "dijit/form/TextBox",
        "./DateTextBox",
        "dojo/_base/declare"
        ], function(kernel, lang, MonthlyCalendar, TextBox, DateTextBox, declare){
                kernel.experimental("dojox/form/DateTextBox");
                return declare( "dojox.form.MonthTextBox", DateTextBox,
                {
                        // summary:
                        //              A validating, serializable, range-bound date text box with a popup calendar that contains only months

                        // popupClass: String
                        //              The popup widget to use. In this case, a calendar with just a Month view.
                        popupClass: MonthlyCalendar,

                        selector: "date",

                        postMixInProperties: function(){
                                this.inherited(arguments);
                                this.constraints.datePattern = "MM";
                        },

                        format: function(value){
                                if(!value && value !== 0){
                                        return 1;
                                }
                                if(value.getMonth){
                                        return value.getMonth() + 1;
                                }
                                return Number(value) + 1;
                        },

                        parse: function(value, constraints){
                                return Number(value) - 1;
                        },

                        serialize: function(value, constraints){
                                return String(value);
                        },

                        validator: function(value){
                                var num = Number(value);
                                var isInt = /(^-?\d\d*$)/.test(String(value));
                                return value == "" || value == null || (isInt && num >= 1 && num <= 12);
                        },

                        _setValueAttr: function(value, priorityChange, formattedValue){
                                if(value){
                                        if(value.getMonth){
                                                value = value.getMonth();
                                        }
                                }
                                TextBox.prototype._setValueAttr.call(this, value, priorityChange, formattedValue);
                        },

                        openDropDown: function(){
                                this.inherited(arguments);

                                this.dropDown.onValueSelected = lang.hitch(this, function(value){
                                        this.focus(); // focus the textbox before the popup closes to avoid reopening the popup
                                        setTimeout(lang.hitch(this, "closeDropDown"), 1); // allow focus time to take
                                        TextBox.prototype._setValueAttr.call(this, value, true, value);
                                });
                        }
                });
});