Cache sweeping is a mechanism which allows you to get around having a ton of +expire_{page,action,fragment}+ calls in your code. It does this by moving all the work required to expire cached content into a +ActionController::Caching::Sweeper+ class. This class is an Observer and looks for changes to an object via callbacks, and when a change occurs it expires the caches associated with that object in an around or after filter.
Cache sweeping is a mechanism which allows you to get around having a ton of +expire_{page,action,fragment}+ calls in your code. It does this by moving all the work required to expire cached content into an +ActionController::Caching::Sweeper+ subclass. This class is an observer and looks for changes to an object via callbacks, and when a change occurs it expires the caches associated with that object in an around or after filter.
Continuing with our Product controller example, we could rewrite it with a sweeper like this:
