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facebookherokusinatrafacebook-canvaskoala

Facebook canvas app not loading, scraper shows correct document

I've created a FB application, hosted on Heroku. The app is written in Ruby.

  1. The app used to load correctly inside facebook iframe.
  2. Now, if I open the app through app.facebook.com/app_namespace, an empty screen is shown. When I have enabled exception trace, it now shows as if the access_token for graph koala object is nil.
  3. If I open Canvas URL, e.g. the "direct" URL everything works fine, but I have to first call direct authroization on facebook through "/auth/facebook".
  4. The iframe now shows koala "Unsupported get method", but through debugging it is evident that access_token obtained from graph is nil.
  5. Behavior is the same for generated test users as well as developer users.

Already tried:

  1. I've tried to debug the Canvas URL through online FB debugger, and Scraper seems to see correct HTML.
  2. Try to reauthorize the app, to no avail.
Solution

  • By default Sinatra uses rack-protection to set the X-Frame_Options header. It looks like this is what is causing your problems.

    You can disable it with this line in your application:

    set :protection, :except => :frame_options