facebook posting

facebook.rb

class Facebook
  attr_accessor :user

  def initialize(user)
    self.user = user
  end

  def post(user, params={})
    params = normalize_params(params, %w(message picture link name caption description source))
    client = OAuth2::Client.new(app_id, app_secret, :site => 'https://graph.facebook.com/', :parse_json => true)
    client.request(:post, "/#{user_token}/feed", fbparams.merge({ :access_token => access_token }))
  end

  def access_token
    if @access_token.nil?
      provider = user.authentications.find_by_provider("facebook")
      @access_token = provider.token if provider.present?
    end
    @access_token
  end

  private
    def normalize_params(params, allowed_params)
      Hash[ *allowed_params.map do |k|
        [k.to_sym, params[k.to_sym]] if params[k.to_sym].present?
      end.select(&:present?).flatten ]
    end
  
    def credentials
      @credentials ||= YAML.load_file(Rails.root.join('config', 'omniauth.yml'))['facebook'].symbolize_keys
    end

    def app_id
      credentials[:app_id]
    end

    def app_secret
      credentials[:app_secret]
    end
end