staticify

A better static asset handler for node.js / express.js

Provides helpers to add a version identifier to your static asset's public URLs, and to remove the hash before serving the file from the file system.

How your URLs are transformed:

/home.css --> /home.<md5 hash of contents>.css

For example:

/home.css --> /home.ae2b1fca515949e5d54fb22b8ed95575.css
/js/script.js --> /js/script.3205c0ded576131ea255ad2bd38b0fb2.js

The version hashes are the md5 of the contents of the static asset. Thus, every file has it's own unique version identifier. When a file changes, only it's own hash changes. This lets you have a far-futures expires header for your static assets without worrying about cache-invalidation, while ensuring that the user only downloads the files that have changed since your last deployment.

With express.js

var staticify = require("staticify")(path.join(__dirname, "public"));

...
app.use(staticify.middleware);

app.helpers({getVersionedPath: staticify.getVersionedPath});

And in your template:

<link href="${getVersionedPath('/home.css')}" rel="stylesheet">

Usage

Install from npm:

npm install staticify

Initialise the staticify helper with the path of your public directory:

var statificy = require("staticify")(path.join(__dirname, "public"));

This returns an object with the following helpers:

.getVersionedPath(path)

Does the following transformation to the path, and returns immediately:

staticify.getVersionedPath('/path/to/file.ext'); // --> /path/to/file.<md5 of the contents of file.ext>.ext

This method is meant to be used inside your templates.

This method is really fast (simply an in-memory lookup) and returns immediately. When you initialize this module, it crawls your public folder synchronously at startup, and pre-determines all the md5 hashes for your static files. This slows down application startup slightly, but it keeps the runtime performance at its peak.

.middleware(req, res, next)

Convenience wrapper over .serve to handle static files in express.js.

app.use(staticify.middleware)  // `app` is your express instance

.replacePaths(string)

Takes the input string, and replaces any paths it can understand. For example:

staticify.replacePaths("body { background: url('/index.js') }");

returns

"body { background: url('/index.d766c4a983224a3696bc4913b9e47305.js') }"

Perfect for use in your build script, to modify references to external paths within your CSS files.

.stripVersion(path)

Removes the md5 identifier in a path.

staticify.stripVersion('/path/to/file.ae2b1fca515949e5d54fb22b8ed95575.ext'); // --> /path/to/file.ext

Note, this function doesn't verify that the hash is valid. It simply finds what looks like a hash and strips it from the path.

.refresh()

Rebuilds the md5 version cache described above. Use this method sparingly. This crawls your public folder synchronously (in a blocking fashion) to rebuild the cache. This is typically only useful when you are doing some kind of live-reloading during development.

.serve(req)

Handles an incoming request for the file. Internally calls .stripVersion to strip the version identifier, and serves the file with a maxage of a year, using send. Returns a stream that can be .piped to a http response stream.

staticify.serve(req).pipe(res)

License

MIT

SunnyGurnani / staticify