The Universal Module Definition (UMD) pattern creates JavaScript libraries that load seamlessly across CommonJS (Node.js), AMD (RequireJS), and browser <script> environments.
UMD with External Dependencies
;(function (root, factory) {
if (typeof define === 'function' && define.amd) {
// AMD. Register as an anonymous module.
define(['b'], factory);
} else if (typeof module === 'object' && module.exports) {
// Node.js / CommonJS
module.exports = factory(require('b'));
} else {
// Browser globals (root is window)
root.myModule = factory(root.b);
}
}(typeof self !== 'undefined' ? self : this, function (b) {
// Module implementation
function myModule() {}
myModule.prototype.doSomething = function () {};
return myModule;
}));
Standalone UMD Without Dependencies
;(function (root, factory) {
if (typeof define === 'function' && define.amd) {
define([], factory);
} else if (typeof module === 'object' && module.exports) {
module.exports = factory();
} else {
root.myUtility = factory();
}
}(typeof self !== 'undefined' ? self : this, function () {
return {
greet: function (name) {
return 'Hello, ' + name + '!';
}
};
}));