node-ensure
A simple library that shims asynchronous module loading into Node.js to help
with building module bundlers and client-side loaders for isomorphic apps.
This library is super slim (read the source) and mainly represents an agreement
between developers and users of a particular bundler/loader.
NOTE: This module is not compatible with Browserify. It is for developers that
want to split their bundles for the client. For example, see
dynapack.
Syntax is inspired by the CommonJS
Modules/Async/A proposal.
Installation
npm install node-ensure
Example
var ensure = require('node-ensure');
ensure(['superagent', 'react'], function(err) {
var request = require('superagent');
var React = require('react');
});
If your bundler needs require.ensure
, do this instead:
require.ensure = require('node-ensure');
require.ensure(['superagent', 'react'], function(err) {
var request = require('superagent');
var React = require('react');
});
Usage
The returned function takes an array of strings and a callback, in that
order (see the example above). The callback takes a single error argument, which
usually indicates a network problem or other client-side loader-specific runtime
error (it should never receive an error when used in Node.js).
Within the ensure callback, load modules with standard require calls.
Bundlers/Loaders
This library primarily constitutes an agreement between users and developers of
module bundlers and (client-side) loaders. The users agree to the usage instructions
supplied above.
Bundlers and/or loaders must adhere to the following:
- The bundler/loader uses the package.json
"browser"
property for replacing
server-only modules with browser-ready counterparts (a la Browserify). - The
require
function passed to a module must have a require.ensure
function. - Each
require.ensure
must accept the same arguments as described in Usage. - Each
require.ensure
must not access variables via closure unless those variables
are shared by all require.ensure
functions. - Each
require.ensure
may access properties
on this
. However, this assumes users have attached node-ensure to require
via
require.ensure = require('node-ensure')
.
Happy loading!
License
MIT