Recently, I was creating some in_place_editors for a polymorphic controller I’m working on. Although the problems not particular to polymorphic controllers, I didn’t want to embed too much model information within the controller. I came up with a way to use meathod_missing to define the in_place_editor_for on demand:
Rails offers three forms of caching within your controller: page, action and fragment. Page caching results in the fastest access times, as the results of the first call to an action are saved in a file so that subsequent accesses never even hit rails. However, for most applications, this isn’t useful, as there may be dynamic content on a page, and this does not allow for authentication. Fragment caching is the most detailed, and allows different parts of a page to be cached and allows you to check for the presence of a cached fragment within your controller (or view), but it requires the most maintenance of cache keys. Action caching is a nice compromise between the two. It allows the controller to get into the action but takes care of cache key creation. It also allows for a dynamic layout using the :layout option. However, in some actions, the amount of work done by the controller may be non-trivial, so it would be nice to check for the presence of the cache within the body of the controller action. This can be solved by borrowing some code from within ActionController::Caching::Actions.