/Ruby on Rails 7.0

class ActionController::Renderer


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:


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)





Public Class Methods

for(controller, env = {}, defaults = DEFAULTS.dup) Show source
# File actionpack/lib/action_controller/renderer.rb, line 48
def self.for(controller, env = {}, defaults = DEFAULTS.dup)
  new(controller, env, defaults)

Create a new renderer instance for a specific controller class.

new(controller, env, defaults) Show source
# File actionpack/lib/action_controller/renderer.rb, line 65
def initialize(controller, env, defaults)
  @controller = controller
  @defaults = defaults
  @env = normalize_keys defaults, env

Accepts a custom Rack environment to render templates in. It will be merged with the default Rack environment defined by ActionController::Renderer::DEFAULTS.

Public Instance Methods

new(env = {}) Show source
# File actionpack/lib/action_controller/renderer.rb, line 53
def new(env = {})
  self.class.new controller, env, defaults

Create a new renderer for the same controller but with a new env.

render(*args) Show source
# File actionpack/lib/action_controller/renderer.rb, line 91
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)

Render templates with any options from ActionController::Base#render_to_string.

The primary options are:

  • :partial - See ActionView::PartialRenderer for details.

  • :file - Renders an explicit template file. Add :locals to pass in, if so desired. It shouldn’t be used directly with unsanitized user input due to lack of validation.

  • :inline - Renders an ERB template string.

  • :plain - Renders provided text and sets the content type as text/plain.

  • :html - Renders the provided HTML safe string, otherwise performs HTML escape on the string first. Sets the content type as text/html.

  • :json - Renders the provided hash or object in JSON. You don't need to call .to_json on the object you want to render.

  • :body - Renders provided text and sets content type of text/plain.

If no options hash is passed or if :update is specified, then:

If an object responding to render_in is passed, render_in is called on the object, passing in the current view context.

Otherwise, a partial is rendered using the second parameter as the locals hash.

Also aliased as: render_to_string
Alias for: render
with_defaults(defaults) Show source
# File actionpack/lib/action_controller/renderer.rb, line 58
def with_defaults(defaults)
  self.class.new controller, @env, self.defaults.merge(defaults)

Create a new renderer for the same controller but with new defaults.

© 2004–2021 David Heinemeier Hansson
Licensed under the MIT License.