simple_form_for错误：未定义的方法-关联的模型

问题描述

| 在我的rails应用程序中，我有两个关联的模型，分别称为Magazine和Article。 杂志

class Magazine < ActiveRecord::Base
  has_many :articles
end

文章

class Article < ActiveRecord::Base
  belongs_to :magazine
end

路线

Magazineapp::Application.routes.draw do
  resources :magazines do
    resources :articles
  end
end

schema.rb

create_table \"articles\",:force => true do |t|
  t.string   \"title\"
  t.string   \"author\"
  t.integer  \"magazine_id\"
  t.datetime \"created_at\"
  t.datetime \"updated_at\"
end

create_table \"magazines\",:force => true do |t|
  t.string   \"title\"
  t.datetime \"created_at\"
  t.datetime \"updated_at\"
end

我正在尝试从文章的新页面创建与杂志相关的新文章。因此，我在杂志的显示页面上创建了一个链接，以将所选杂志传递到新文章的页面。 views / magazines / show.html.erb

<p id=\"notice\"><%= notice %></p>
<p>
  <b>Title:</b>
  <%= @magazine.title %>
</p>

<%= link_to \'Edit\',edit_magazine_path(@magazine) %> |
<%= link_to \'Back\',magazines_path %> |
<%= link_to \'New Article\',new_magazine_article_path(@magazine) %>

在文章的新页面中呈现的部分内容是： views / articles / _form.html.erb

<%= simple_form_for([@magazine,@article]) do |f| %>
  <%= f.error_notification %>

  <div class=\"inputs\">
    <%= f.input :title %>
    <%= f.input :author %>
  </div>

  <div class=\"actions\">
    <%= f.button :submit %>
  </div>
<% end %>

从文章的控制器创建方法是：

def create

  @magazine = Magazine.find(params[:magazine_id])    
  @article = @magazine.articles.create(params[:article])

  respond_to do |format|
    if @article.save
      format.html { redirect_to(@article,:notice => \'Article was successfully created.\') }
      format.xml  { render :xml => @article,:status => :created,:location => @article }
    else
      format.html { render :action => \"new\" }
      format.xml  { render :xml => @article.errors,:status => :unprocessable_entity }
    end
  end
end

但是，当我尝试创建与该杂志相关的新文章时，我收到了错误消息：

Showing /home/wilson/magazineapp/app/views/articles/_form.html.erb where line #1 raised:

undefined method `articles_path\' for #<#<Class:0x00000001944070>:0x00000001926ed0>
Extracted source (around line #1):

1: <%= simple_form_for([@magazine,@article]) do |f| %>
2:   <%= f.error_notification %>
3: 
4:   <div class=\"inputs\">

Request

Parameters:

{\"magazine_id\"=>\"2\"}

耙路

    magazine_articles GET    /magazines/:magazine_id/articles(.:format)          {:action=>\"index\",:controller=>\"articles\"}
                      POST   /magazines/:magazine_id/articles(.:format)          {:action=>\"create\",:controller=>\"articles\"}
 new_magazine_article GET    /magazines/:magazine_id/articles/new(.:format)      {:action=>\"new\",:controller=>\"articles\"}
edit_magazine_article GET    /magazines/:magazine_id/articles/:id/edit(.:format) {:action=>\"edit\",:controller=>\"articles\"}
     magazine_article GET    /magazines/:magazine_id/articles/:id(.:format)      {:action=>\"show\",:controller=>\"articles\"}
                      PUT    /magazines/:magazine_id/articles/:id(.:format)      {:action=>\"update\",:controller=>\"articles\"}
                      DELETE /magazines/:magazine_id/articles/:id(.:format)      {:action=>\"destroy\",:controller=>\"articles\"}
            magazines GET    /magazines(.:format)                                {:action=>\"index\",:controller=>\"magazines\"}
                      POST   /magazines(.:format)                                {:action=>\"create\",:controller=>\"magazines\"}
         new_magazine GET    /magazines/new(.:format)                            {:action=>\"new\",:controller=>\"magazines\"}
        edit_magazine GET    /magazines/:id/edit(.:format)                       {:action=>\"edit\",:controller=>\"magazines\"}
             magazine GET    /magazines/:id(.:format)                            {:action=>\"show\",:controller=>\"magazines\"}
                      PUT    /magazines/:id(.:format)                            {:action=>\"update\",:controller=>\"magazines\"}
                      DELETE /magazines/:id(.:format)                            {:action=>\"destroy\",:controller=>\"magazines\"}

我怎么解决这个问题？在这种情况下，传递给simple_form_for的正确参数是什么？     

解决方法

嵌套资源后，必须确保始终在请求之间传递更高级别的资源。 您的路线将是使用耙路时注意到的路线。 该表格应如下所示：

<%= simple_form_for([@magazine,@article]) do |f| %>
  <%= f.error_notification %>

  <div class=\"inputs\">
    <%= f.input :title %>
    <%= f.input :author %>
  </div>    
  <div class=\"actions\">
    <%= f.button :submit %>
  </div>
<% end %>

这样，您现在必须在文章控制器和文章查看页面（其中包括杂志本身）上的所有地方使用新路线。 您在控制器中的创建动作将是：

def create

  @magazine = Magazine.find(params[:magazine_id])    
  @article = @magazine.articles.create(params[:article])

  respond_to do |format|
    if @article.save
      format.html { redirect_to([@magazine,@article],:notice => \'Article was successfully created.\') }
      format.xml  { render :xml => @article,:status => :created,:location => @article }
    else
      format.html { render :action => \"new\" }
      format.xml  { render :xml => @article.errors,:status => :unprocessable_entity }
    end
  end
end

因此，现在您的所有路线也都应引用@magazine。     ,在控制台中运行

rake routes

，并确保存在

articles_path

。 似乎应该命名为

magazines_articles_path(...)