Simple Browserify middleware for Express with basic in-memory caching and watchify support.

README.md

Simple Browserify middleware for Express with basic in-memory caching and watchify support.

I created this as a Gist instead of Node module because Browserify bundles are one of those things better left customizable. This function, as it stands, is very limited. It has no support for things like transforms and plugins. Copy this into your app and add any desired functionality there.

Depends on:

• Browserify - tested on v6.1, expected to work on v4.0+
• Watchify - tested on v2.0, expected to work on v1.0+. Watchify is optional. Remove watchify require statement if not desired.
• Express - tested with v4.9, expected to work with v3.0+

Usage

browserifyMiddleware( entryFileName [, options ] )

• entryFileName (String) - The entry file to be browserified. Relative to current working directory.
• options (Object) - A hash of options. A few properties are specific to this middleware and the rest are passed to the Browserify bundle.
  • watchify (Boolean) - Use watchify. Clears the cache whenever files change, forcing the bundle to be rebuilt on next request. Useless if cacheResult is false.
  • cacheResult (Boolean) - Cache the result in memory. Without watchify enabled, the browserify bundle will only compile once. The default value is true.

Example

This example creates a bundle from the file client/index.js, with watchify and serves it up at /browser.js.

app.get("/browser.js", browserifyMiddleware("client/index.js", { debug: true, watchify: true });

License

(c) 2014 Tyler Johnson MIT License

browserify-middlware.js

/* Node Dependencies */
var browserify = require("browserify"),
	watchify = require("watchify"),
	path = require("path");

/* Middlware Generator */
var browserifyMiddleware =
module.exports = function(jsfile, options) {
	var bundle, cached_src;
	
	// set up options
	options = options || {};
	options.cacheResult = options.cacheResult == null ? true : options.cacheResult;
	options.watchify = options.watchify && options.cacheResult;
	
	// apply watchify options
	if (options.watchify) Object.keys(watchify.args).forEach(function(key) {
		if (typeof options[key] === "undefined") options[key] = watchify.args[key];
	});

	// create a new browserify bundle
	bundle = browserify(options);
	
	// apply watchify
	if (options.watchify) {
		watchify(bundle);

		bundle.on("update", function(ids) {
			cached_src = null;
		});
	}
	
	// add the initial file
	bundle.add(path.resolve(jsfile));
	
	// sends the js source
	function send(res, src) {
		res.type("js");
		res.status(200);
		res.send(src);
	}

	// the actual middleware
	return function(req, res, next) {
		// check for cached copy
		if (options.cacheResult && cached_src) {
			return send(res, cached_src);
		}

		// otherwise build a new one
		bundle.bundle(function(err, src) {
			if (err) return next(err);
			if (options.cacheResult) cached_src = src
			send(res, src);
		});
	}
}