如何同时创建父元素和子元素

问：

我想同时创建一个和关于。While Invoice 和 InvoiceItem .如何在 Rails 7 中执行此类操作，以便用户可以通过 Turbo 将多个 invoiceItems 添加到他们的发票中？我不需要知道 TurboStreams 和其他东西是如何工作的，因为我很熟悉，但我只是无法让 InvoiceItems 与 Invoice 同时创建。 我已经找到了这篇文章，但无法从中获得任何有用的信息。InvoiceInvoiceItemshas_many :invoice_itemsbelongs_to :invoice

模型

发票.rb

class Invoice < ApplicationRecord
  belongs_to :project
  
  has_many :invoice_items, foreign_key: :invoice_id # not sure if this foreign_key is necessary
  accepts_nested_attributes_for :invoice_items
end

invoice_item.rb

class InvoiceItem < ApplicationRecord
  belongs_to :invoice
end

控制器

Invoice_controller.rb

  def create
    @project = Project.find(params[:project_id])
    @client = Client.find(params[:client_id])
    @invoice = @project.invoices.new(invoice_params)
    @invoice_item = @invoice.invoice_items.new
    @invoice.invoice_items_attributes = [:invoice_id, :amount]

    @invoice.client_id = @client.id

    respond_to do |format|
      if @invoice.save

....

    def invoice_params
      params.require(:invoice).permit(... :invoice_item, invoice_item_attributes: [:id, :invoice_id, :amount, ...])
    end

目前，我尝试使用发票表单的内部，例如：form_for

<%= form.fields_for @invoice.invoice_items.build do |lorem| %>

这让我在控制台中出现以下错误（但按预期保存发票：

Unpermitted parameter: :invoice_item. Context: { controller: InvoicesController, action: create, request: #<ActionDispatch::Request:0x000000010a0c8d88>, params: {"authenticity_token"=>"[FILTERED]", "invoice"=>{..., "invoice_item"=>{"invoice_id"=>"", "amount"=>"3"}}, "button"=>"", "controller"=>"invoices", "action"=>"create", "user_id"=>"1", "client_id"=>"1", "project_id"=>"1"} }

请注意，invoice_id不会传递给invoice_item。

通过控制台，类似

@invoice = Invoice.new
@invoice.invoice_items.new(amount: "3", ...)
@invoice.save!

确实工作得很奇怪，但它不能转化为我的代码。 我在这里做错了什么？