Rails Ruby on Rails → 3.x

Comments and changes to this ticket

• 

  Jeff Kreeftmeijer November 1st, 2010 @ 05:03 PM

  • Importance changed from “” to “Low”

  Automatic cleanup of spam.

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  Bob Lail December 30th, 2010 @ 08:31 PM

  • Tag set to “actioncontroller workaround doublerendererror render bug”

  Although abstract_controller/rendering.rb:91 would lead you to believe that response_body is only set when you call render (and not when you call render_to_string), that isn't the case in Rails 3.0.3. If you try an experiment along the following lines, you'll see that response_body has been written:

  def index
    test = render_to_string(:template => "main/index")
    Rails.logger.info response_body
    # ...
  end
  

  Because response_body is not nil, action_controller/metal/rendering.rb:16 raises AbstractController::DoubleRenderError. You'd think that you can refactor your example like this:

  class TestController < ApplicationController
    def test
      json = render_to_string(:json => "[]")
      response_body = nil
      render :text => json
    end
  end
  

  but there's a catch. There's a second response_body accessor! It's in abstract_controller/base.rb:14. So what you'd actually write is:

  class TestController < ApplicationController
    def test
      json = render_to_string(:json => "[]")
      @_response_body = nil
      render :text => json
    end
  end
  

  That should serve as a workaround for now.

• 

  Neeraj Singh January 21st, 2011 @ 07:21 PM

  • State changed from “new” to “open”
  • Milestone set to “3.x”
  • Tag changed from “actioncontroller workaround doublerendererror render bug” to “actioncontroller workaround doublerendererror render bug, patched”
  • Assigned user set to “José Valim”

  This is an edge case. You will run into this error only if you are using

  render_to_string(:json => '')
  render_to_string(:xml => '')
  render_to_string(:js => '')
  

  That is because of following code

      add :json do |json, options|
        json = json.to_json(options) unless json.kind_of?(String)
        json = "#{options[:callback]}(#{json})" unless options[:callback].blank?
        self.content_type ||= Mime::JSON
        self.response_body  = json
      end
  
      add :js do |js, options|
        self.content_type ||= Mime::JS
        self.response_body  = js.respond_to?(:to_js) ? js.to_js(options) : js
      end
  
      add :xml do |xml, options|
        self.content_type ||= Mime::XML
        self.response_body  = xml.respond_to?(:to_xml) ? xml.to_xml(options) : xml
      end
  

  I would say that render_to_string should always ensure that response_body is set to nil. I have attached a patch and a test.

• 

  Neeraj Singh January 21st, 2011 @ 07:23 PM

  LH did not attache my patch last time.

  • 5875_fix.diff 1.9 KB
• 

  José Valim January 21st, 2011 @ 07:24 PM

  Patch seems to be empty. Neeraj, just tell me the commit hash in your fork please. :)

• 

  José Valim January 21st, 2011 @ 07:25 PM

  @BobLail, your first response_body does not work because you are creating a local variable instead of calling a method. "self.response_body = nil" should do the trick.

• 

  Neeraj Singh January 21st, 2011 @ 07:26 PM

  LH is still not liking it . Here is the patch

  https://github.com/neerajdotname/rails/commit/fea223330ca8a5887b01c...

• 

  José Valim January 21st, 2011 @ 07:34 PM

  Neeraj, do we need to manipulate the instance variable directly? Couldn't we simply call self.response_body = nil?

• 

  Neeraj Singh January 21st, 2011 @ 08:05 PM

  My tests were failing with setting self.response_body = nil

  def render_to_string
  .....
  self.response_body = nil
  end
  
  #/metal/rendering.rb
  puts response_body #=> [nil]
  raise ::AbstractController::DoubleRenderError if response_body
  

  I did not dig into why it is this way. It worked with @_response_body = nil and I left it. Guess I was being lazy.

  Will look into it later.

• 

  Neeraj Singh January 21st, 2011 @ 08:49 PM

  Setting self.response_body = nil become [ nil ] because of this line of code

     # action_controller/metal.rb
     def response_body=(val)
        body = val.respond_to?(:each) ? val : [val]
        super body
      end
  

• 

  José Valim January 21st, 2011 @ 09:46 PM

  We could also change this file to properly handle nil. Wdyt?

• 

  Neeraj Singh January 22nd, 2011 @ 12:24 AM

  Here is an improved version.

  https://github.com/neerajdotname/rails/compare/master...t_5875app

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  Bob Lail January 22nd, 2011 @ 06:52 PM

  (oops. Good call, José.)

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  Bob Lail January 22nd, 2011 @ 06:52 PM

  (oops. Good call, José.)

• 

  José Valim January 25th, 2011 @ 07:14 PM

  • State changed from “open” to “resolved”

  Applied, thanks Neeraj!

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  bingbing March 26th, 2011 @ 01:33 AM

  gucci watches