Module: ActionController::Rendering

Extended by:
ActiveSupport::Concern
Included in:
Base, DataStreaming
Defined in:
lib/action_controller/metal/rendering.rb

Defined Under Namespace

Modules: ClassMethods

Constant Summary collapse

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

Instance Method Summary collapse

Instance Method Details

#render(*args) ⇒ Object

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

– Check for double render errors and set the content_type after rendering.

Raises:



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# File 'lib/action_controller/metal/rendering.rb', line 165

def render(*args)
  raise ::AbstractController::DoubleRenderError if response_body
  super
end

#render_to_body(options = {}) ⇒ Object

:nodoc:



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# File 'lib/action_controller/metal/rendering.rb', line 185

def render_to_body(options = {}) # :nodoc:
  super || _render_in_priorities(options) || " "
end

#render_to_string ⇒ Object

Similar to #render, but only returns the rendered template as a string, instead of setting ‘self.response_body`. – Override render_to_string because body can now be set to a Rack body.



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# File 'lib/action_controller/metal/rendering.rb', line 174

def render_to_string(*)
  result = super
  if result.respond_to?(:each)
    string = +""
    result.each { |r| string << r }
    string
  else
    result
  end
end