module ActionController::Rendering
Constants
Public instance methods
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 nothtml_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 "<h1>Hello, World!</h1>"
: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 callingto_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 callingformat
on the renderable if it responds toformat
, falling back totext/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
ortrue
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 165
def render(*args)
raise ::AbstractController::DoubleRenderError if response_body
super
end
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 174
def render_to_string(*)
result = super
if result.respond_to?(:each)
string = +""
result.each { |r| string << r }
string
else
result
end
end