source: Dev/trunk/src/client/dijit/form/CurrencyTextBox.js

define([
        "dojo/currency", // currency._mixInDefaults currency.format currency.parse currency.regexp
        "dojo/_base/declare", // declare
        "dojo/_base/lang", // lang.hitch
        "./NumberTextBox"
], function(currency, declare, lang, NumberTextBox){

        // module:
        //              dijit/form/CurrencyTextBox

        /*=====
        var __Constraints = declare([NumberTextBox.__Constraints, currency.__FormatOptions, currency.__ParseOptions], {
                // summary:
                //              Specifies both the rules on valid/invalid values (minimum, maximum,
                //              number of required decimal places), and also formatting options for
                //              displaying the value when the field is not focused (currency symbol,
                //              etc.)
                // description:
                //              Follows the pattern of `dijit/form/NumberTextBox.__Constraints`.
                //              In general developers won't need to set this parameter
                // example:
                //              To ensure that the user types in the cents (for example, 1.00 instead of just 1):
                //      |               {fractional:true}
        });
        =====*/

        return declare("dijit.form.CurrencyTextBox", NumberTextBox, {
                // summary:
                //              A validating currency textbox
                // description:
                //              CurrencyTextBox is similar to `dijit/form/NumberTextBox` but has a few
                //              extra features related to currency:
                //
                //              1. After specifying the currency type (american dollars, euros, etc.) it automatically
                //                      sets parse/format options such as how many decimal places to show.
                //              2. The currency mark (dollar sign, euro mark, etc.) is displayed when the field is blurred
                //                      but erased during editing, so that the user can just enter a plain number.

                // currency: [const] String
                //              the [ISO4217](http://en.wikipedia.org/wiki/ISO_4217) currency code, a three letter sequence like "USD"
                currency: "",

                /*=====
                // constraints: __Constraints
                //              Despite the name, this parameter specifies both constraints on the input
                //              (including minimum/maximum allowed values) as well as
                //              formatting options.
                constraints: {},
                ======*/

                baseClass: "dijitTextBox dijitCurrencyTextBox",

                // Override NumberTextBox._formatter to deal with currencies, ex: converts "123.45" to "$123.45"
                _formatter: currency.format,

                _parser: currency.parse,

                _regExpGenerator: currency.regexp,

                parse: function(/*String*/ value, /*Object*/ constraints){
                        // summary:
                        //              Parses string value as a Currency, according to the constraints object
                        // tags:
                        //              protected extension
                        var v = this.inherited(arguments);
                        if(isNaN(v) && /\d+/.test(value)){ // currency parse failed, but it could be because they are using NumberTextBox format so try its parse
                                v = lang.hitch(lang.delegate(this, { _parser: NumberTextBox.prototype._parser }), "inherited")(arguments);
                        }
                        return v;
                },

                _setConstraintsAttr: function(/*Object*/ constraints){
                        if(!constraints.currency && this.currency){
                                constraints.currency = this.currency;
                        }
                        this.inherited(arguments, [ currency._mixInDefaults(lang.mixin(constraints, { exponent: false })) ]); // get places
                }
        });
});