从new动作创建User嵌套StockShipment记录时遇未授权参数错误

你遇到的Unpermitted parameter: :stock_shipments错误，核心是表单结构、控制器逻辑和强参数三者不匹配：

1. 你试图通过User的嵌套属性创建多个StockShipment，但表单却以[@user, @stock_shipment]为模型，导致参数结构混乱；
2. 控制器create方法错误地尝试单独构建StockShipment，而非通过User的嵌套属性批量创建；
3. 强参数配置的是StockShipment的嵌套属性，但实际参数结构不符合预期。

1. 修正表单结构 #

表单应以User为核心模型，利用fields_for生成多个StockShipment的嵌套字段：

<%= form_with model: @user do |form| %>
  <!-- 循环生成多个StockShipment字段，默认构建2个可按需调整 -->
  <%= form.fields_for :stock_shipments do |shipment_form| %>
    <%= render 'shared/shipment_fields', form: shipment_form, locals: { user: current_user, user_stock: @user_stock } %>
  <% end %>

  <!-- 添加提交按钮 -->
  <%= form.submit "Confirmar envíos" %>
<% end %>

2. 调整控制器逻辑 #

new动作：为用户预构建多个空的StockShipment #

def new
  @user = current_user
  # 预构建2个StockShipment，可根据需求修改数量
  2.times { @user.stock_shipments.build }
  # 按需获取UserStock，若参数来自路由可调整为params[:user_stock_id]
  @user_stock = UserStock.find(...)
end

create动作：通过User更新批量创建StockShipment #

def create
  @user = current_user
  @user_stock = UserStock.find(params[:user][:stock_shipments_attributes].values.first[:user_stock_id])

  if @user.update(user_params)
    # 给每个新创建的StockShipment发送通知邮件
    @user.stock_shipments.last(params[:user][:stock_shipments_attributes].size).each do |shipment|
      ShipmentNotificationMailer.new_shipment_notification(shipment).deliver_later
    end
    redirect_to user_stock_shipments_path(current_user), status: :see_other
  else
    puts @user.errors.full_messages.inspect
    render :new
  end
end

3. 修正强参数配置 #

现在需要允许User模型的stock_shipments_attributes，而非StockShipment的嵌套属性：

private

def user_params
  params.require(:user).permit(
    stock_shipments_attributes: [
      :id, :country, :phone, :email, :name, :quantity, :address, :city,
      :province, :postalcode, :surname, :user_id, :campaign_id, :gift_selection_id,
      :delivery_date, :stock_variation, :description, :user_stock_id, :_destroy
    ]
  )
end

4. 确认关联关系 #

确保User和StockShipment的关联定义正确：

# app/models/user.rb
class User < ApplicationRecord
  has_many :stock_shipments, dependent: :destroy
  accepts_nested_attributes_for :stock_shipments, reject_if: :all_blank, allow_destroy: true
end

# app/models/stock_shipment.rb
class StockShipment < ApplicationRecord
  belongs_to :user
end

• 表单以User为模型后，提交的参数会变为user[stock_shipments_attributes][...]，与强参数配置匹配；
• 通过@user.update(user_params)触发嵌套属性的批量创建，无需单独调用build和save；
• 如果需要支持动态添加/删除StockShipment字段，可结合JavaScript实现，但当前方案先解决批量创建的核心问题。

内容的提问来源于stack exchange，提问作者user3074558