def load_filters
      filters_config = self.params["filters_config" ]
      if !filters_config.nil? && File.exists?(filters_config)
        begin
          YAML::load_file(filters_config)
        rescue 
          on_error.trigger($!, $@)
        end
      end
    end
def load_filters
      filters_config = self.params["filters_config" ]
      if !filters_config.nil? && File.exists?(filters_config)
        begin
          YAML::load_file(filters_config)
        rescue 
          on_error.trigger($!, $@)
        end
      end
    end
load the YAML file that is specified in the params