gistfile1.txt

class TwitterReverseAuthController < ApplicationController
  def api_key_exchange
    credential_args = [:screen_name, :token, :secret].map{|x| params[x]}

    user_credentials = UserCredentials.new(*credential_args)
    if user_credentials.valid?
      user  = user_credentials.user
      token = params[:token]
      device = Device.find_or_create_by_token!(:token       => user_credentials.token,
                                               :description => params[:description],
                                               :user_id     => @user.id)
      render :json => { :api_key => device.api_key }
    else
      render :json => { :error => user_credentials.first_error}, :status => :unprocessable_entity }
    end
  end
end

class UserCredentials
  def initialize(screen_name, token, secret)
    # ...
  end

  def valid?
    # ...
  end

  def first_error
    # ...
  end
end

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