Flash [：notice]虚拟属性未定义方法错误

Question

我的目标是创建一个搜索表单，以查看用户列表并在下一页显示。如果未填写f_name和l_name字段，则用户将在下一页上收到flash消息。我使用attr_accessor在模型中设置要在控制器中访问的虚拟属性，但我最终得到以下错误：

ArgumentError in AttendeesController#index
wrong number of arguments (0 for 2) 

编辑1 -  或者，当我在rails控制台中键入Attendee.flash（'f_name'，l_name'）时，我经常会收到错误。

NoMethodError: undefined method `flash_notice=' for #<Class:0x007ffe12b5dc28>

为什么说我的参数数量错误？

这是我的控制器：

1 class AttendeesController < ApplicationController
2   # GET /attendees
3   # GET /attendees.json
4   def index
5     @attendees = Attendee.search(params[:f_name], params[:l_name])
6     
7     flash[:notice] = @attendees.flash(params[:f_name], params[:l_name])
8     
9     respond_to do |format|
10       format.html # index.html.erb
11       format.json { render json: @attendees }
12     end
13   end
14   

这是我的模特：

1 class Attendee < ActiveRecord::Base
2   attr_accessor :flash_notice 
3 
4   def self.search(f_name, l_name) 
5     if f_name.presence && l_name.presence
6       where("f_name = ? AND l_name = ?", f_name, l_name) 
7       
8     else
9      self.flash
10    end
11   end
12 
13   def self.flash(f_name, l_name)
14       self.flash_notice = "First name is present but last name is not present." if f_name.presence == true && l_name.presence == nil 
15       self.flash_notice = "First name is not present but last name is present." if f_name.presence == nil && l_name.presence == true 
16       self.flash_notice = "Both names aren't present!" if f_name.presence && l_name.presence == nil 
17   end