Comments on: Caching and MIME Types in Rails

By: Ilya Grigorik

Ilya Grigorik — Tue, 01 Jul 2008 00:36:03 +0000

Cedric, awesome, thank you for sharing the Apache config! It looks like we came up with the same solution, albeit for Nginx at AideRSS: Nginx and Memcached.

By: Cédric DELTHEIL

Cédric DELTHEIL — Wed, 25 Jun 2008 07:22:27 +0000

Ilya,

Forcing type is a nice trick!

On my own, I experienced some other problems with the combination of page caching and REST style architecture while using different formats (ie. Rails respond_to).
In other words, I noticed that your rewriting rules should be robust enough to handle the use or not of format as query string:

GET /foo/1?format=json GET /foo/1.json

So how can we handle MIME type and various format together? I suggest the following Apache configuration that does the trick:

# 1. Rewrite when the format is specified as a query string # eg. /foo/1?format=json => /foo/1.json RewriteCond %{QUERY_STRING} format=(html|xml|json) RewriteRule ^(.*)$ $1.%1


# 2. Rewrite to check for static

# eg. /foo/1.json => /cache/foo/1.json

RewriteRule ^(.+\.(html|xml|json))$ /cache$1
# 3. Force the MIME type with 'type' special flag

# eg. remember /cache/foo/1.json to have MIME-type 'application/json'

RewriteCond $1 ^.+\.json$

RewriteRule ^(.*)$ $1 [T=application/json]

# etc such forcing other types or redirecting non-statics requests

Hope it’ll be useful to someone else!

By: Ilya Grigorik

Ilya Grigorik — Tue, 18 Mar 2008 12:36:34 +0000

Nick, I submitted the patch to Chris before, but it never made it in. And you’re right, I also had to modify the code when porting to Rails 2.x - unfortunately I wasn’t smart enough to make a diff at the time! Any chance you can submit your changes?

With luck it’ll get integrated this time.

By: Nick Grandy

Nick Grandy — Tue, 11 Mar 2008 03:40:50 +0000

Ilya,
Great patch, thanks a ton. I was having trouble caching RJS actions in Rails - that is, actions that product javascript. I’d think this is a pretty critical workaround for anyone trying to do the same. FYI, The patch no longer seems entirely compatible with cache fu. I had to get in there and apply part of the patch manually. But all the better - now I actually see what’s going on. Would be great if this gets incorporated into cache fu. Chris just opened up a new git repository to help accomodate changes.

By: Ilya Grigorik

Ilya Grigorik — Thu, 31 Jan 2008 06:28:18 +0000

Andrew, I don’t think the patch made it into the trunk. Having said that, I’m aware of at least several sites that are using it now!

As for page caching, yes that would be ideal. However, in a lot of cases you simply can’t rely on file extensions due to URI structure, and hence all MIME magic tends to break down.

By: Andrew Turner

Andrew Turner — Tue, 29 Jan 2008 18:33:45 +0000

Was this ever acccepted into cache_fu proper?

Also, it seems awkward to require a different action to handle just RSS. This is the purpose of the respond_to block for single action logic, different methods of rendering.

What would be the best would be if the page caching stored the static page with the appropriate extension and MIME-Type.