Change HTTP Response Code using Rails and RABL

Question

I am using RABL for my REST API. However, currently, even if there is an error, the HTTP response code I get is 200. Is there a way to change this to a 4xx level code? It would be great for my client to read.

I am not using the render template: "api/v1/error.rabl” because if I do use it, there is an after filter that sets CORS access control headers which does not get executed.

I tried searching, but didn’t find a way.

Answer 1

Seems like this answer provides a good solution. For example,

class FoosController < ActionController::Base
  respond_to :json

  class ApiResponder < ActionController::Responder
    def to_format
      case
      when has_errors?
        controller.response.status = :unprocessable_entity
      when get? && !resource
        controller.response.status = :not_found
      when post?
        controller.response.status = :created
      end

      default_render
    rescue ActionView::MissingTemplate => e
      api_behavior(e)
    end
  end
  self.responder = ApiResponder

  def show
    @foo = Foo.find(params[:id])
    @foo.errors.add(:base, "foo bar") # e.g. of errors on the object
    respond_with @foo
  end
end

Although the wiki has a warning that "setting controller.response.status is like a default value", respond_with or render shouldn't explicitly set status and it seems like a call to render "my_template" triggers that 200 you mentioned. If you do want to reuse a single error template, something like the author's suggested template, this works:

  ...

  self.responder = ApiResponder

  def show
    @foo = Foo.find(params[:id])
    @foo.errors.add(:base, "foo bar") # e.g. of errors on the object
    respond_with @foo do |format|
      if @foo.errors.empty?
        flash[:notice] = 'Foo was successfully created.'
      else
        format.json { render "error" }
      end
    end
  end

# error.rabl
object false

node :errors do
  {
    :message => "Sorry, fubar'ed",
    :code => 12345
  }
end

This works with actions that write as well as read. The original bug discussion also has some interesting examples.