Skip to Content Skip to Search

module ActionController::Rendering

Constants

RENDER_FORMATS_IN_PRIORITY = [:body, :plain, :html]
 

Public instance methods

render(*args)

Permalink

Renders a template and assigns the result to self.response_body.

If no rendering mode option is specified, the template will be derived from the first argument.

render "posts/show"
# => renders app/views/posts/show.html.erb

# In a PostsController action...
render :show
# => renders app/views/posts/show.html.erb

If the first argument responds to render_in, the template will be rendered by calling render_in with the current view context.

Rendering Mode

:partial

See ActionView::PartialRenderer for details.

render partial: "posts/form", locals: { post: Post.new }
# => renders app/views/posts/_form.html.erb
:file

Renders the contents of a file. This option should not be used with unsanitized user input.

render file: "/path/to/some/file"
# => renders /path/to/some/file
:inline

Renders an ERB template string.

@name = "World"
render inline: "<h1>Hello, <%= @name %>!</h1>"
# => renders "<h1>Hello, World!</h1>"
:body

Renders the provided text, and sets the content type as text/plain.

render body: "Hello, World!"
# => renders "Hello, World!"
:plain

Renders the provided text, and sets the content type as text/plain.

render plain: "Hello, World!"
# => renders "Hello, World!"
:html

Renders the provided HTML string, and sets the content type as text/html. If the string is not html_safe?, performs HTML escaping on the string before rendering.

render html: "<h1>Hello, World!</h1>".html_safe
# => renders "<h1>Hello, World!</h1>"

render html: "<h1>Hello, World!</h1>"
# => renders "&lt;h1&gt;Hello, World!&lt;/h1&gt;"
:json

Renders the provided object as JSON, and sets the content type as application/json. If the object is not a string, it will be converted to JSON by calling to_json.

render json: { hello: "world" }
# => renders "{\"hello\":\"world\"}"

By default, when a rendering mode is specified, no layout template is rendered.

Options

:assigns

Hash of instance variable assignments for the template.

render inline: "<h1>Hello, <%= @name %>!</h1>", assigns: { name: "World" }
# => renders "<h1>Hello, World!</h1>"
:locals

Hash of local variable assignments for the template.

render inline: "<h1>Hello, <%= name %>!</h1>", locals: { name: "World" }
# => renders "<h1>Hello, World!</h1>"
:layout

The layout template to render. Can also be false or true to disable or (re)enable the default layout template.

render "posts/show", layout: "holiday"
# => renders app/views/posts/show.html.erb with the app/views/layouts/holiday.html.erb layout

render "posts/show", layout: false
# => renders app/views/posts/show.html.erb with no layout

render inline: "<h1>Hello, World!</h1>", layout: true
# => renders "<h1>Hello, World!</h1>" with the default layout
:status

The HTTP status code to send with the response. Can be specified as a number or as the status name in Symbol form. Defaults to 200.

render "posts/new", status: 422
# => renders app/views/posts/new.html.erb with HTTP status code 422

render "posts/new", status: :unprocessable_entity
# => renders app/views/posts/new.html.erb with HTTP status code 422
Source code GitHub
# File actionpack/lib/action_controller/metal/rendering.rb, line 137
def render(*args)
  raise ::AbstractController::DoubleRenderError if response_body
  super
end

render_to_string(*)

Permalink

Similar to render, but only returns the rendered template as a string, instead of setting self.response_body.

Source code GitHub
# File actionpack/lib/action_controller/metal/rendering.rb, line 146
def render_to_string(*)
  result = super
  if result.respond_to?(:each)
    string = +""
    result.each { |r| string << r }
    string
  else
    result
  end
end

Namespace

Definition files