defunctzombie / polyfill-middleware

selectively serve javascript polyfills based on user-agent

polyfill-middleware

http and express middleware serves selective polyfills for javascript based on the requesting user-agent.

which polyfills?

See the polyfill project for details about which polyfills and browsers are supported.

install

npm install polyfill-middleware

use with express

You can use the polyfill middleware with express by specifying which path to serve the dynamically generated js from.

The below examples assumes the following script tag <script src="/assets/polyfill.js"></script>

var polyfill = require('polyfill-middleware');

app.use('/assets/polyfill.js', polyfill());

// alternatively you can limit to just `get` requests
app.get('/assets/polyfill.js', polyfill());

use with node.js http server

The middleware function takes 3 arguments (request, response, done). done should be a function and will be called if the polyfill middleware encountered an error. If there was no error, polyfill middleware will respond to the request.

var middleware = polyfill();

http.createServer(function(req, res) {
    // .. some logic to determine if the request should be handled by polyfill
    middleware(req, res, function(err) {
    });
});

examples

More examples are available in the examples directory.

polyfill-middleware's Issues

caching

Cache files in memory.

Not sure at what layer to cache yet. Possibly at the final bundle (we can actually precompute those on startup). Or just each file.

compress

need an option to compress the final js output

separate lib from middleware

would be cool if the polyfill-creating portion was separated into its own lib, then have the middleware be a separate lib again. just because.