composed_of & fields_for

Question

所以我读过&重新读过关于这个话题的文章(http://www.stephenchu.com/2008/05/rails-composedof-validation.html)，但是我没有任何运气。

根据money 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

好瘦控制器

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

视图(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:未定义的方法‘美分’用于{“美分”=>“6.66”，“货币”“=>”美元}：HashWithIndifferentAccess

‘composed_of’散列以‘美分’的形式传递到中，但根据本文的说法，它应该使用表单中的params中的'amount‘属性。我真的被困住了

Answer 1

编辑:我以前误解了你的问题。是的，在您的表单中，您需要这样引用amount：

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