@js gist: loading test.

constants.js

self.Constants = function () {
    var _constants = {};
    return {
        get: function (name) {
            return _constants[name];
        },
        add: function (name, value) {
            if(typeof _constants[name] != "undefined") {
                return value;
            }
            _constants[name] = value;
            return _constants[name] == value;
        },
        del: function (name) {
            return delete _constants[name];
        },
        all: function () {
            return _constants;
        }
    };
};

self.constant = Constants();