The UMD pattern typically attempts to offer compatibility with the most popular script loaders of the day (e.g RequireJS amongst others). In many cases it uses AMD as a base, with special-casing added to handle CommonJS compatibility.
// Uses Node, AMD or browser globals to create a module.
// If you want something that will work in other stricter CommonJS environments,
// or if you need to create a circular dependency, see commonJsStrict.js
// Defines a module "returnExports" that depends another module called "b".
// Note that the name of the module is implied by the file name. It is best
// if the file name and the exported global have matching names.
// If the 'b' module also uses this type of boilerplate, then
// in the browser, it will create a global .b that is used below.
// If you do not want to support the browser global path, then you
// can remove the `root` use and the passing `this` as the first arg to
// the top function.
(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. Does not work with strict CommonJS, but
// only CommonJS-like environments that support module.exports,
// like Node.
module.exports = factory(require('b'));
} else {
// Browser globals (root is window)
root.returnExports = factory(root.b);
}
}(this, function (b) {
//use b in some fashion.
// Just return a value to define the module export.
// This example returns an object, but the module
// can return a function as the exported value.
return {};
}));
// if the module has no dependencies, the above pattern can be simplified to
(function (root, factory) {
if (typeof define === 'function' && define.amd) {
// AMD. Register as an anonymous module.
define([], factory);
} else if (typeof module === 'object' && module.exports) {
// Node. Does not work with strict CommonJS, but
// only CommonJS-like environments that support module.exports,
// like Node.
module.exports = factory();
} else {
// Browser globals (root is window)
root.returnExports = factory();
}
}(this, function () {
// Just return a value to define the module export.
// This example returns an object, but the module
// can return a function as the exported value.
return {};
}));