module ActionController::Renderers::ClassMethods

+controller._renderers+ will be nil, and the action will fail.
You must specify a +use_renderer+, else the +controller.renderer+ and

end
end
render json: record
def show

use_renderers :json

include ActionController::Renderers
include ActionController::Rendering
include AbstractController::Rendering
class MetalRenderingController < ActionController::Metal

(+_render_with_renderer_json+) might look like:
+use_renderers+. For example, a controller that includes only the :json renderer
you may specify which renderers to include by passing the renderer name or names to
Rather than including ActionController::Renderers::All and including all renderers,

and ActionController::Renderers, and have at least one renderer.
must include AbstractController::Rendering, ActionController::Rendering,
Since ActionController::Metal controllers cannot render, the controller

available in the controller. See Renderers::RENDERERS and Renderers.add.
include ActionController::Renderers::All, making all renderers
Both ActionController::Base and ActionController::API

otherwise to add an available renderer proc to a specific controller.
It is useful when rendering from an ActionController::Metal controller or

to call within controller actions.
Adds, by name, a renderer or renderers to the +_renderers+ available

def use_renderers(*args)
  renderers = _renderers + args
  self._renderers = renderers.freeze
end