使用Rails 3的嵌套资源来正确关联模型

Question

我想要获得更好的Rail的嵌套资源句柄，并且使用模型School和类作了测试应用。在我routes.rb文件，我有：

resources :schools do 
    resources :classes 
end 

随着学校和级以下车型的关系：

class School < ActiveRecord::Base 
    attr_accessible: name 
    has_many :classes 
end 

和

class Class < ActiveRecord::Base 
    attr_accessible: name, school_id 
    belongs_to :school 
end 

我有困难得到school_id与在像0这样的URL下创建的帖子相关联。更确切地说，我想定义一个像current_school这样的帮助器方法，它可以将URI的前半部分包含school_id，以允许我在控制器中编写函数，如current_school.posts.all，该函数将自动提取与school_id =网址中有什么。谢谢！

* 编辑

这是我在ClassController：

class ClassesController < ApplicationController 

    def index 
    @classes = current_school.classes.all 
    end 

    def new 
    @class = current_school.classes.build 
    end 

    def create 
    @class = current_school.classes.build(params[:post]) 
    if @class.save 
     redirect_to root_path #this will be further modified once I figure out what to do 
    else 
     redirect_to 'new' 
    end 
    end 

    private 

    def current_school 
    @current_school ||= School.find(params[:school_id]) 
    end 

end 

而在new.html.erb文件：

<div class="span6 offset3"> 
    <%= form_for([@school, @class]) do |f| %> 

     <%= f.label :name, "class title" %> 
     <%= f.text_field :name %> 

     <%= f.submit "Create class", class: "btn btn-large btn-primary" %> 
    <% end %> 
    </div> 

Answer 1

当你窝你的资源，你会得到一些帮助免费方法如解释here。您正在寻找的方法将被写成之一：

new_school_class_path(@school) 
new_school_class_path(@school_id) 

虽然你的类索引页将是：

school_classes_path(@school) 
school_classes_path(@school_id) 

在你ClassesController，你会做这样的事情：

def index 
    @classes = current_school.classes 
end 

def new 
    @class = current_school.classes.build 
end 

private 
def current_school 
    @current_school ||= School.find(params[:school_id]) 
end