Rails 4嵌套属性更新时有多个记录 [英] Rails 4 nested attributes multiple records when updating

问题描述

我被卡住了，我不知道为什么它不能正常工作. 我有一个模型产品，其中有很多标签. 当我更新产品栏时，会正确更新产品属性，但会创建另一个标签记录，而不仅仅是更新它.

I'm stuck and i don't know why it is not working right. I have a model product wich has many tags. When i update the product rails update properly the products attributes but is creating another tag record instead of just updating it.

这是我的代码:

查看表单:

 <%= form_for ([@product.user, @product]), id: 'edit_form' do |f| %>
      <%= render 'shared/error_messages', object: f.object %>

      <div class="field">
        <%= f.label :name %><br>
        <%= f.text_field :name %>
      </div>
      <div class="field">
        <%= f.label :description %><br>
        <%= f.text_area :description %>
      </div>

      <div class="field">
        <%= f.fields_for :tags do |t| %>
          <%= t.label :name %>
          <%= t.text_field :name %>
        <% end %>
      </div>


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

产品型号:

 class Product < ActiveRecord::Base

      belongs_to :user, :foreign_key => "user_id"
      has_many :tags, :dependent => :destroy
      accepts_nested_attributes_for :tags, reject_if: :all_blank, allow_destroy: true, :update_only => true
    end

标签模型:

 class Tag < ActiveRecord::Base
        belongs_to :product, :foreign_key => "product_id"
        # before_save { name.downcase! }

    end

产品控制器:

 def edit
        user = User.find(params[:user_id])
        @product = user.products.find(params[:id])
        @tags = @product.tags.all

      respond_to do |format|
            format.html
            format.js
        end 
      end

      def update
          user = User.find(params[:user_id])
          @product = user.products.find(params[:id])
          @tags = @product.tags.all

        respond_to do |format|
          if  @product.update(product_params)
            format.html { redirect_to([@product.user, @product], :notice => 'Product successfully updated.') }
          else
            format.html { render :action => "edit" }
          end
        end
      end

    def product_params
          params.require(:product).permit(:name, :description, tags_attributes: :name)
        end

非常感谢

推荐答案

您必须在控制器的允许参数中传递标签ID

You have to pass the tag id in the permit params in your controller

def product_params
  params.require(:product).permit(:name, :description, tags_attributes: [:id,:name])
end

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