Minified Cache is a Ruby on Rails Plugin that takes rails built-in asset caching one step further by optimizing javascript_include_tag..cache=>... to be minified!

Check out the official github page at:

Sample file reductions:

prototype.js (version from 127kb to 94kb saves 33kb (26% size reduction)
prototype.js, effects.js, dragdrop.js, controls.js (rails :defaults): from 229kb to 168kb saves 61kb (27% size reduction)

Note: this plugin was put together on rails 2.2.2. It probably needs some tweaking for older rails versions.

Minified Cache README:
This monkey patch of ActionView::Helpers::AssetTagHelper uses the jsmin library to minify cached
javascript so that you can pass the YSlow test! When you call:
    <%= javascript_include_tag 'application', 'other_js_source', :cache => 'application_cached' %>
then the resulting generated #{RAILS_ROOT}/public/javascripts/application_cached.js will be
served minified (assuming config.action_controller.perform_caching = true)
git clone git:// vendor/plugins/minified_cache && rm -rf vendor/plugins/minified_cache/.git
In order to minify your javascript, it must be formatted with appropriate function closure and
braces eg:
    if(condition) alert('msg')
    else alert('othermsg')
is handled gracefully by browsers (thanks to the newline), however when it gets compressed to:
    if(condition) alert('msg')else alert('othermsg')
you can expect some kaboom.
check out to verify your scripts
Copyright (c) 2009 Jason Kotchoff, released under the MIT license