Module: ActionController::Rendering

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.

class Greeting
  def render_in(view_context)
    view_context.render html: "<h1>Hello, World</h1>"
  end

  def format
    :html
  end
end

render(Greeting.new)
# => "<h1>Hello, World</h1>"

render(renderable: Greeting.new)
# => "<h1>Hello, World</h1>"

#### 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\"}"

:renderable : Renders the provided object by calling render_in with the current view

context. The response format is determined by calling {format} on the
renderable if it responds to {format}, falling back to {text/html} by
default.

    render renderable: Greeting.new
    # => renders "<h1>Hello, World</h1>"

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