jquery select下拉选项框 二级联动 rails后台

当选择大分类的时候 小分类跟着改变

 

model

 

class Category < ActiveRecord::Base
  has_many :subcategories
end

 

class Subcategory < ActiveRecord::Base
  belongs_to :category
end

 

view

 

<%= collection_select(:usedbook,:name,@categories,:id,:name) %>
 <span id="next_select"> <%= collection_select(:usedbook,:subcategory_id,@subcategories,:id,:name) %> </span>

 

<%= select(:usedbook, :subcategory_id, @subcategories) %>

 

控制器

 def select_with_ajax
    @subcategories=Subcategory.all(:conditions => ["category_id=?",params[:category_id]]).collect{|subcategory|
                                                 [subcategory.name,subcategory.id]}
    render(:layout=>false)
  end

 

Jquery

 

$('#usedbook_name').change(function(){


           v =$(this).val();
           $("#next_select").hide();


           $('#next_select').load("select_with_ajax",{category_id:v}).show();
          });