motion/input_helpers.rb
def bind
      raise ModelNotSetError.new("You must set the model before binding it.") unless @model

      fields do |field|
        view_obj = self.view.viewWithTag(field.tag)
        @model.send("#{field.name}=".to_sym, view_obj.text) if view_obj.respond_to?(:text)
      end
    end
def bind
      raise ModelNotSetError.new("You must set the model before binding it.") unless @model

      fields do |field|
        view_obj = self.view.viewWithTag(field.tag)
        @model.send("#{field.name}=".to_sym, view_obj.text) if view_obj.respond_to?(:text)
      end
    end
+bind+ fetches all mapped fields from
 any subview of the current +UIView+
 and transfers the contents to the
 corresponding fields of the model
 specified by the +model+ method.