require "set" module ActionController # See Renderers.add def self.add_renderer(key, &block) Renderers.add(key, &block) end # See Renderers.remove def self.remove_renderer(key) Renderers.remove(key) end # See Responder#api_behavior class MissingRenderer < LoadError def initialize(format) super "No renderer defined for format: #{format}" end end module Renderers extend ActiveSupport::Concern # A Set containing renderer names that correspond to available renderer procs. # Default values are :json, :js, :xml. RENDERERS = Set.new included do class_attribute :_renderers, default: Set.new.freeze end # Used in ActionController::Base # and ActionController::API to include all # renderers by default. module All extend ActiveSupport::Concern include Renderers included do self._renderers = RENDERERS end end # Adds a new renderer to call within controller actions. # A renderer is invoked by passing its name as an option to # AbstractController::Rendering#render. To create a renderer # pass it a name and a block. The block takes two arguments, the first # is the value paired with its key and the second is the remaining # hash of options passed to +render+. # # Create a csv renderer: # # ActionController::Renderers.add :csv do |obj, options| # filename = options[:filename] || 'data' # str = obj.respond_to?(:to_csv) ? obj.to_csv : obj.to_s # send_data str, type: Mime[:csv], # disposition: "attachment; filename=#{filename}.csv" # end # # Note that we used Mime[:csv] for the csv mime type as it comes with Rails. # For a custom renderer, you'll need to register a mime type with # Mime::Type.register. # # To use the csv renderer in a controller action: # # def show # @csvable = Csvable.find(params[:id]) # respond_to do |format| # format.html # format.csv { render csv: @csvable, filename: @csvable.name } # end # end def self.add(key, &block) define_method(_render_with_renderer_method_name(key), &block) RENDERERS << key.to_sym end # This method is the opposite of add method. # # To remove a csv renderer: # # ActionController::Renderers.remove(:csv) def self.remove(key) RENDERERS.delete(key.to_sym) method_name = _render_with_renderer_method_name(key) remove_method(method_name) if method_defined?(method_name) end def self._render_with_renderer_method_name(key) "_render_with_renderer_#{key}" end module ClassMethods # Adds, by name, a renderer or renderers to the +_renderers+ available # to call within controller actions. # # It is useful when rendering from an ActionController::Metal controller or # otherwise to add an available renderer proc to a specific controller. # # Both ActionController::Base and ActionController::API # include ActionController::Renderers::All, making all renderers # available in the controller. See Renderers::RENDERERS and Renderers.add. # # Since ActionController::Metal controllers cannot render, the controller # must include AbstractController::Rendering, ActionController::Rendering, # and ActionController::Renderers, and have at least one renderer. # # Rather than including ActionController::Renderers::All and including all renderers, # you may specify which renderers to include by passing the renderer name or names to # +use_renderers+. For example, a controller that includes only the :json renderer # (+_render_with_renderer_json+) might look like: # # class MetalRenderingController < ActionController::Metal # include AbstractController::Rendering # include ActionController::Rendering # include ActionController::Renderers # # use_renderers :json # # def show # render json: record # end # end # # You must specify a +use_renderer+, else the +controller.renderer+ and # +controller._renderers+ will be nil, and the action will fail. def use_renderers(*args) renderers = _renderers + args self._renderers = renderers.freeze end alias use_renderer use_renderers end # Called by +render+ in AbstractController::Rendering # which sets the return value as the +response_body+. # # If no renderer is found, +super+ returns control to # ActionView::Rendering.render_to_body, if present. def render_to_body(options) _render_to_body_with_renderer(options) || super end def _render_to_body_with_renderer(options) _renderers.each do |name| if options.key?(name) _process_options(options) method_name = Renderers._render_with_renderer_method_name(name) return send(method_name, options.delete(name), options) end end nil end add :json do |json, options| json = json.to_json(options) unless json.kind_of?(String) if options[:callback].present? if content_type.nil? || content_type == Mime[:json] self.content_type = Mime[:js] end "/**/#{options[:callback]}(#{json})" else self.content_type ||= Mime[:json] json end end add :js do |js, options| self.content_type ||= Mime[:js] js.respond_to?(:to_js) ? js.to_js(options) : js end add :xml do |xml, options| self.content_type ||= Mime[:xml] xml.respond_to?(:to_xml) ? xml.to_xml(options) : xml end end end