Font Assets

This little gem helps serve font-face assets in Rails 3.1. It really does these two things:

Responds with "proper" mime types for woff, eot, tff, and svg font files, and
Sets Access-Control-Allow-Origin response headers for font assets, which Firefox requires for cross domain fonts.

In addition, it will also respond to the pre-flight OPTIONS requests made by supporting browsers (Firefox).

Important

This gem only works if you are NOT precompiling your assets in production, because it requires asset requests to go through the Rails app, and if you precompile your assets then you are most likely serving them through a web server like NGINX. If this is the case, don't use this gem but instead look into configuring the CORS headers for font requests. For example, here is a way to do that in NGINX.

Install

Add font_assets to your Gemfile:

gem 'font_assets'

Usage

By default, in a Rails application, this gem should Just Work™. However, the default settings allow any requesting site to use the linked fonts, due to the Allowed Origin being '*', by default. This is only useful for browsers which support this feature (Firefox), but restricting it to certain domains may be beneficial.

Set the origin domain that will get set in the Access-Control-Allow-Origin header:

# in config/environments/production.rb
config.font_assets.origin = 'http://codeschool.com'

The origin domain must match the domain of the site serving the page that is requesting the font, not the host of the font. For example, if you are using a CDN to serve your assets (like CloudFront), and the full path to the font asset is http://d3rd6rvl24noqd.cloudfront.net/assets/fonts/Pacifico-webfont-734f1436e605566ae2f1c132905e28b2.woff, but the URI the user is visiting is http://coffeescript.codeschool.com/level/1, you'd want to set the origin header to this:

config.font_assets.origin = 'http://coffeescript.codeschool.com'

To match the actual Origin value, omit the trailing slash (details).

An Example Response

Below is an example response for a .woff font asset on a Rails 3.1 application running behind several proxies and caches (including CloudFront):

$ curl -i http://d1tijy5l7mg5kk.cloudfront.net/assets/ubuntu/Ubuntu-Bold-webfont-4bcb5239bfd34be67bc07901959fc6e1.woff
HTTP/1.0 200 OK
Server: nginx
Date: Sat, 14 Jan 2012 19:45:19 GMT
Content-Type: application/x-font-woff
Last-Modified: Sat, 14 Jan 2012 16:58:14 GMT
Cache-Control: public, max-age=31557600
Access-Control-Allow-Origin: http://www.codeschool.com
Access-Control-Allow-Methods: GET
Access-Control-Allow-Headers: x-requested-with
Access-Control-Max-Age: 3628800
X-Content-Digest: 66049433125f563329c4178848643536f76459e5
X-Rack-Cache: fresh
Content-Length: 17440
X-Varnish: 311344447
Age: 289983
X-Cache: Hit from cloudfront
X-Amz-Cf-Id: 9yzifs_hIQF_MxPLwSR8zck3eZVXJ8LFKpMUpXnu2SmMuEmyrUbHdQ==,Lbh9kfjr0YRm77seSmOSQ6oFkUEMabvtFStJLhTOy9BfGrIXVneoKQ==
Via: 1.1 varnish, 1.0 2815dd16e8c2a0074b81a6148bd8aa3a.cloudfront.net:11180 (CloudFront), 1.0 f9e7403ca14431787835521769ace98a.cloudfront.net:11180 (CloudFront)
Connection: close

In it, you can see where this middleware has injected the Content-Type and Access-Control-* headers into the response.

And below is an example OPTIONS request response:

$ curl -i -X OPTIONS http://www.codeschool.com/
HTTP/1.1 200 OK
Server: nginx
Date: Wed, 18 Jan 2012 04:13:25 GMT
Connection: keep-alive
Access-Control-Allow-Origin: http://www.codeschool.com
Access-Control-Allow-Methods: GET
Access-Control-Allow-Headers: x-requested-with
Access-Control-Max-Age: 3628800
Vary: Accept-Encoding
X-Rack-Cache: invalidate, pass
Content-Length: 0

License

Font Assets is released under the MIT license.