Question

My problem is on facebook callback url. I am using fbgraph gem on Rails 3.0.

I ask for extended permissions on my tab application. So in the callback I wait code parameter and access_token.

I extract this code from fbgraph official GIT repository.

    def authorize
        begin
          @auth.client.authorization_code = params[:code]
#In access_token line should return me access__token but throw a error message (see below)
          access_token = @auth.client.access_token! # => Rack::OAuth2::AccessToken
          @facebook_user = FbGraph::User.me(access_token).fetch # => FbGraph::User
    #MORE CODE WITHOUT IMPORTANCE
          redirect_to :controller => "dashboard", :action => "index"
        rescue Exception => e
           logger.info(e.message)
        end
      end

Throw this error message:

Rack::OAuth::Client::Error # => @status = 400, Message => Missing redirect uri

Please I need help quickly. Excuse me and thanks in advance

Answer 1

I’m using the fb_graph gem which is similar. In order to get the access_token you also need to supply the callback URI – this is the fb_graph version:

client.redirect_uri = "http://your.callback.uri"
client.authorization_code = params[:code]
access_token = client.access_token!

Update:

Looking at the fbgraph gem documentation I think you need to replace these two lines:

@auth.client.authorization_code = params[:code]
access_token = @auth.client.access_token!

With this:

access_token = @auth.client.authorization.process_callback(params[:code], :redirect_uri => callback_url)

To be honest I looked at using the fbgraph gem but the documentation was so bad that I switched to fb_graph instead which is similar and actually has some useful examples in the documentation.