A better controller?

better_controller.rb

class WidgetsController

  def index
    IndexedResourceCommand.new(Widget).execute(params, default_responder)
  end

  def create
    CreateResourceCommand.new(Widget).execute(params, default_responder)
  end

  private

  def default_responder
    # could have a different responder for different content-types (e.g. respond_to)
    RenderOrRedirectResponder.new(self) # needs self to get access to controller rendering behaviour
  end

end

class ResourceCommand

  def initialize(scope)
    @scope = scope
  end

end

class IndexResourceCommand

  def execute(params, responder)
    responder.respond_with_collection(@scope.all)
  end

end

class CreateResourceCommand

  def execute(params, responder)
    instance = @scope.new(params)

    if instance
      responder.respond_with_saved_object(instance)
    else
      responder.respond_with_unsaved_object(instance)
    end
  end

end

class RenderOrRedirectResponder

  def respond_with_collection(collection)
    # set up assigns and render the appropriate template
  end

  def respond_with_saved_object(object)
    @controller.redirect_to url_for(object)
  end

  def respond_with_unsaved_object(object)
    # set up assigns and render template with errors
  end

end

So if I understand you right, your basically using the controller as a port where data comes in? If you were to cover them with integration tests, what would you assert on?

Well, I guess that would depend on the user stories.

I have no idea if this would actually be a good design having not explored it further, more than anything I feel that Rails controllers are probably the weakest part of an app from an OOP point of view and I'm interested in ways of investigating a better approach, whether or not this is it. :)