ruby-on-rails - 组成的＆fields_for

Question

所以我已经阅读并重新阅读了关于该主题的 Stephen Chu 文章（http://www.stephenchu.com/2008/05/rails-composedof-validation.html），但是我没有任何运气。

根据货币 gem 文档 money.rubyforge .org 中提供的示例

模型

class Payment < ActiveRecord::Base
  composed_of :amount,
    :class_name => "Money",
    :mapping => [%w(cents cents), %w(currency currency_as_string)],
    :constructor => Proc.new { |cents, currency| Money.new(cents || 0, currency || Money.default_currency) }
end

漂亮的瘦控制器

class PaymentsController < ApplicationController
  def create
    @payment = Payment.new(params[:payment])
    ...
  end
end

查看 (HAML)

- form_for @payment do |p|
  - p.fields_for :amount, @payment.amount do |a|
    = a.label :cents
    = a.text_field :cents
    = a.label :currency
    = a.text_field :currency, :value => :usd

我收到的错误是：{"cents"=>"6.66", "currency"=>"usd"}:HashWithIndifferentAccess 的未定义方法`cents'

'amount' 散列被作为'cents' 传递给composer_of，但根据文章，它应该在表单的参数中使用'amount' 的属性。我真的被困住了：/

Answer 1

编辑：我之前误解了你的问题。是的，在您的表格中，您需要以amount这种方式引用：

- form_for @payment do |p|
   = a.label :dollars
   = a.text_field :amount
   = a.label :currency
   = a.text_field :currency, :value => :usd