npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

express-negotiator

v1.1.0

Published

Express/connect middleware that does HTTP content negotiation for static files

Downloads

15,745

Readme

express-negotiator

Express/connect middleware for doing content negotiation with static files on disc. Heavily inspired by Apache's mod_negotiation.

Negotiator rewrites req.url to the negotiated file name based on these factors (in descending order of importance):

  • Whether req.url matches a file name on disc exactly
  • The locale GET parameter
  • The value of a locale cookie (optional, specified by options.cookieName)
  • The Accept-Language and Accept headers

... and of course the availability of suitable files on disc. If no acceptable match is found, req.url is left untouched.

Like mod_negotiation, express-negotiator interprets the extensions of the files on disc as an unordered set. A file called foo.html.fr would be treated the same as one called foo.fr.html except when the request url specifies an exact match.

The negotiator middleware is intended to run right before static pointed at the same directory as options.root.

If options.cookieName is specified, the cookieParser middleware must also be in the middleware chain.

Conditional requests

When the url is rewritten, negotiator sets the ETag header to the same value as the static middleware would ("<size>-<modificationTime>"), but with the negotiated Content-Type and locale id bits suffixed. This prevents false positive 304 responses with If-None-Match when the same client (or reverse proxy) requests the same url later with different headers (eg. after a locale cookie change). That would happen if the files happened to have the same size and modification times.

Also, the If-Modified-Since header is removed since that would cause the static middleware to reply 304 Not Modified in similar situations. ETags are a superior concept anyway.

Installation

Make sure you have node.js and npm installed, then run:

$ npm install express-negotiator

Example usage

var express = require('express'),
    negotiator = require('express-negotiator'),
    root = '/path/to/static/files',
    app = express.createServer();

app
    .use(express.cookieParser())
    .use(negotiator({root: root, cookieName: 'mycookie'}))
    .use(express.static(root))
    .listen(1337);

If the root dir contains the files index.en.html, index.da.html, and foo.png these example requests would be rewritten as follows:

GET / HTTP/1.1
Accept: text/html
Accept-Language: en

=> /index.en.html
Response ETag: "<size>-<modificationTime>-text/html-en"
GET /?locale=da HTTP/1.1
Accept: text/html
Accept-Language: en

=> /index.da.html
Response ETag: "<size>-<modificationTime>-text/html-da"
GET /index HTTP/1.1
Cookie: mycookie=da
Accept: text/html
Accept-Language: en

=> /index.da.html
Response ETag: "<size>-<modificationTime>-text/html-da"
GET /foo HTTP/1.1
Accept: image/*

=> /foo.png
Response ETag: "<size>-<modificationTime>-image/png"

See the test suite for more examples.

License

express-negotiator is licensed under a standard 3-clause BSD license -- see the LICENSE file for details.