在Rails应用程序中实例化错误

时间:2012-08-16 13:59:05

标签: ruby-on-rails ruby-on-rails-3 model-view-controller controller instantiation

我正在开发一个Rails应用程序,其中我有两个模型,即chef模型和dish模型。

class Dish < ActiveRecord::Base
  belongs_to :chef
  attr_accessible :description, :photo, :price
  validates :chef_id, presence: true
  has_attached_file :photo
end 

class Chef < ActiveRecord::Base
  attr_accessible :name, :email, :mobile ,:password, :password_confirmation, :postcode
  has_many :dishes
  has_secure_password 
end

我(厨师)正试图通过转到/上传网址创建一个菜,其视图是

<%= form_for(@dish) do |d| %>  
  <%= d.label :description, "Please name your dish..."%>
  <%= d.text_field(:description)%>

  <%= d.label :price, "What should the price of the dish be..."%>
  <%= d.number_field(:price)%>

  <%= d.submit "Submit this Dish", class: "btn btn-large btn-primary"%>
<% end %> 

我希望创建的菜肴出现在厨师的展示页面上,

<% provide(:title, @chef.name)%>       
  <div class = "row">
    <aside class = "span4">
      <h1><%= @chef.name %></h1>
      <h2><%= @chef.dishes%></h2>       
     </aside>
   <div>
<% end %>

而且,dishes_controller是:

class DishesController < ApplicationController  

  def create
    @dish = chef.dishes.build(params[:dish])
    if @dish.save
      redirect_to chef_path(@chef)
    else
      render 'static_pages/home'
    end

但是当我尝试从/ upload url创建一个菜时,我在dishes_controller中收到以下错误:

NameError undefined local variable or method `chef' for #<DishesController:0x3465494>   

app/controllers/dishes_controller.rb:5:in `create'

我想我已经实例化了所有变量,但问题仍然存在。

1 个答案:

答案 0 :(得分:1)

在这一行:

@dish = chef.dishes.build(params[:dish])

chef变量未实例化。你必须做这样的事情:

@chef = Chef.find(params[:chef_id])
@dish = @chef.dishes.build(params[:dish])

这样在使用@chef变量之前就会填充它。