Makes CommonJS-incompatible modules browserifyable.
**Table of Contents** *generated with [DocToc](http://doctoc.herokuapp.com/)*
browserify . -d -o bundle.js
- You Will Always
- You will sometimes
- a) Expose global variables via
- b) Use aliases
- c) Provide an external shim config
- d) Diagnose what browserify-shim is doing
- a) Expose global variables via
- Multi Shim Example including dependencies
- More Examples
npm install browserify-shim
For a version compatible with email@example.com run
npm install firstname.lastname@example.org instead.
For a version compatible with the v2 API
npm install email@example.com instead.
The core features of browserify-shim are:
- Shims non-CommonJS modules in order for them to be browserified by specifying an alias, the path to the file,
and the identifier under which the module attaches itself to the global
dependsfor shimming libraries that depend on other libraries being in the global namespace.
- applies shims configured inside the dependencies of your package
Additionally, it handles the following real-world edge cases:
- Modules that just declare a
var foo = ...on the script level and assume it gets attached to the
windowobject. Since the only way they will ever be run is in the global context — "ahem, … NO?!"
undefined, in order to fix improperly-authored libraries that need shimming but try anyway to use AMD or CommonJS. For more info read the comment inside this fixture
- removes invalid requires, i.e.
'jquery'isn't installed due to the library being improperly published or installed incorrectly via a downloader like bower
browserify-shim is a proper
browserify transform you can publish packages with files that need to be shimmed,
granted that you specify the shim config inside the
browserify resolves your package it will run the
browserify-shim transform and thus shim what's necessary
when generating the bundle.
In most cases you want to install it as a devDependency via:
npm install -D browserify-shim
The above includes
./js/vendor/jquery.js (relative to the
package.json) in the bundle and exports
Additionally it exposes
three, so you can
var three = require('three'). More info
jquery does not depend on other shimmed modules and thus has no
depends field, we used the short form to
specify its exports, however the example above is equivalent to:
In some cases the libraries you are using are very large and you'd prefer to add them via a script tag instead to get the following benefits:
- faster bundling times since the library is not included in the bundle
- pull libraries from a CDN which allows it to be pulled straight from the user's browser cache in case it was downloaded before
We'll show how this works by taking the rather huge yet awesome
THREE.js library as an example:
<!-- index.html -->
In case you are using an external shim config, you may achieve the same by specifying the global via an
moduleexports ='three': exports: 'global:THREE'
var THREE = require'three';
You want to avoid spreading the knowledge that
THREE is a global and stay consistent in how you resolve dependencies.
THREE would ever be published to npm and you decide to install it from there,
you don't have to change any of your code since it already is
requireing it properly.
You may expose files under a different name via the
browser field and refer to them under that alias in the shim config:
This also allows you to require this module under the alias, i.e.:
var $ = require('jquery').
The external shim format is very similar to the way in which the shim is specified inside the
below for more details.
You may encounter problems when your shim config isn't properly setup. In that case you can diagnose them via the
Simply set the flag when building your bundle, i.e.:
BROWSERIFYSHIM_DIAGNOSTICS=1 browserify -d . -o js/bundle.js
or in a
build.js script add:
process.env.BROWSERIFYSHIM_DIAGNOSTICS=1 to the top.
Some libraries depend on other libraries to have attached their exports to the window for historical reasons :(. (Hopefully soon we can truly say that this bad design is history.)
In this contrived example we are shimming four libraries since none of them are commonJS compatible:
- x exports window.$
- x-ui exports nothing since it just attaches itself to x. Therefore x-ui depends on x.
- y exports window.Y and also depends on x expecting to find it on the window as $.
- z exports window.zorro and depends on x and y. It expects to find x on the window as $, but y on the window as YNOT, which is actually different than the name under which y exports itself.
We will be using the
depends field in order to ensure that a dependency is included and initialized before a library
that depends on it is initialized.
Below are three examples, each showing a way to properly shim the above mentioned modules.
depends array consists of entries of the format
depends entries make use of the aliases as well
moduleexports ='../vendor/x.js' : 'exports': '$''../vendor/x-ui.js' : 'depends': '../vendor/x.js': null'../vendor/y.js' : 'exports': 'Y' 'depends': '../vendor/x.js': '$''../vendor/z.js' : 'exports': 'zorro' 'depends': '../vendor/x.js': '$' '../vendor/y.js': 'YNOT'
Note: all paths are relative to
./config/shim.js instead of the
The main difference to
a) is the
depends field specification. Instead it being an array of strings it expresses its dependencies as a hashmap:
- value: the name under which it is expected to be attached on the window
- the tests are a great resource to investigate the
different ways to configure shims and to understand how shims are applied to packages found inside the
node_modulesof your package