require "active_support/core_ext/hash/keys" module ActionController # ActionController::Renderer allows you to render arbitrary templates # without requirement of being in controller actions. # # You get a concrete renderer class by invoking ActionController::Base#renderer. # For example, # # ApplicationController.renderer # # It allows you to call method #render directly. # # ApplicationController.renderer.render template: '...' # # You can use this shortcut in a controller, instead of the previous example: # # ApplicationController.render template: '...' # # #render allows you to use the same options that you can use when rendering in a controller. # For example, # # FooController.render :action, locals: { ... }, assigns: { ... } # # The template will be rendered in a Rack environment which is accessible through # ActionController::Renderer#env. You can set it up in two ways: # # * by changing renderer defaults, like # # ApplicationController.renderer.defaults # => hash with default Rack environment # # * by initializing an instance of renderer by passing it a custom environment. # # ApplicationController.renderer.new(method: 'post', https: true) # class Renderer attr_reader :defaults, :controller DEFAULTS = { http_host: "example.org", https: false, method: "get", script_name: "", input: "" }.freeze # Create a new renderer instance for a specific controller class. def self.for(controller, env = {}, defaults = DEFAULTS.dup) new(controller, env, defaults) end # Create a new renderer for the same controller but with a new env. def new(env = {}) self.class.new controller, env, defaults end # Create a new renderer for the same controller but with new defaults. def with_defaults(defaults) self.class.new controller, env, self.defaults.merge(defaults) end # Accepts a custom Rack environment to render templates in. # It will be merged with the default Rack environment defined by # +ActionController::Renderer::DEFAULTS+. def initialize(controller, env, defaults) @controller = controller @defaults = defaults @env = normalize_keys defaults.merge(env) end # Render templates with any options from ActionController::Base#render_to_string. def render(*args) raise "missing controller" unless controller request = ActionDispatch::Request.new @env request.routes = controller._routes instance = controller.new instance.set_request! request instance.set_response! controller.make_response!(request) instance.render_to_string(*args) end private def normalize_keys(env) new_env = {} env.each_pair { |k, v| new_env[rack_key_for(k)] = rack_value_for(k, v) } new_env end RACK_KEY_TRANSLATION = { http_host: "HTTP_HOST", https: "HTTPS", method: "REQUEST_METHOD", script_name: "SCRIPT_NAME", input: "rack.input" } IDENTITY = ->(_) { _ } RACK_VALUE_TRANSLATION = { https: ->(v) { v ? "on" : "off" }, method: ->(v) { v.upcase }, } def rack_key_for(key) RACK_KEY_TRANSLATION.fetch(key, key.to_s) end def rack_value_for(key, value) RACK_VALUE_TRANSLATION.fetch(key, IDENTITY).call value end end end