如何使用 rails_gem : cocoon, 一级分类-新增二级分类
效果实例：
1.添加gem: (Inside your Gemfile add the following:)
gem "cocoon"
2.application.js:
//= require cocoon
3.新增一级分类的增删改查和二级分类的model：
Suppose you have a GoodsFirstCategory model:
rails g scaffold GoodsFirstCategory name:string
新增二级分类的model和表：
rails g model RestaurantGoodsSecondCategory name:string goods_first_category_id:integer
4.添加model之间的关系：
class GoodsFirstCategory < ActiveRecord::Base
has_many :restaurant_goods_second_categories, :before_add => :set_second_category
accepts_nested_attributes_for :restaurant_goods_second_categories, allow_destroy: true
has_many :goods
def set_second_category(restaurant_goods_second_category)
restaurant_goods_second_category.goods_first_category ||= self
end
end
class RestaurantGoodsSecondCategory < ActiveRecord::Base
belongs_to :goods_first_category
has_many :goods
end
5.在 views/goods_first_categories/_form中添加代码：
<div id="second_category" style="display: none">
<div class="form-action">
<%= link_to_add_association '新增二级分类', f, :restaurant_goods_second_categories, class: 'btn btn-success',
'data-association-insertion-node' => '.restaurant_goods_second_categories',
'data-association-insertion-method' => 'append' %>
</div>
<div class="restaurant_goods_second_categories">
<%= f.fields_for :restaurant_goods_second_categories do |gsc| %>
<%= render 'restaurant_goods_second_category_fields', f: gsc %>
<% end %>
</div>
</div>
6.在 app/views/goods_first_categories/_restaurant_goods_second_category_fields.html.erb 添加：
<div class="detail-tr form-action">
<%= f.text_field :name, :class => 'form-control', placeholder: '例如: 猪肉' %>
<%= link_to_remove_association('删除', f,
{ wrapper_class: 'detail-tr' })%>
<%= f.hidden_field :id %>
</div>
现在应该能增加二级分类了。