如何使用accept_nested_attributes_for手動構建正確的嵌套窗體？

Question

我正在嘗試爲測試目的手動構建表單域。我有以下型號：

class Bedroom < ActiveRecord::Base 
    has_many :booked_bedrooms 
    has_many :bookings, :through => :booked_bedrooms 
end 

class Booking < ActiveRecord::Base 
    has_many :booked_bedrooms 
    has_many :bedrooms, :through => :booked_bedrooms 
    accepts_nested_attributes_for :booked_bedrooms 
end 

class BookedBedroom < ActiveRecord::Base 
    belongs_to :booking 
    belongs_to :bedroom 
    # fields: bedroom_id, :booking_id 
end 

當我嘗試在控制檯下面，登記，相關booked_bedroom獲取保存：

>> b = Booking.new({ :booked_bedrooms_attributes => { 0 => { :bedroom_id => 1 } } }) 
=> #<Booking id: nil, start_date: nil, end_date: nil, created_at: nil, updated_at: nil> 
>> b.save 
=> true 
>> b.booked_bedrooms 
=> [#<BookedBedroom id: 1, booking_id: 1, bedroom_id: 1, created_at: "2010-06-22 18:55:57", updated_at: "2010-06-22 18:55:57">] 

所以我建立這樣一種形式：

<% form_for @booking do |form| %> 
<% for bedroom in @available_bedrooms %> 

      <%= check_box_tag "booked_bedrooms_attributes[#{bedroom.id}][bedroom_id]", bedroom.id %> <%= bedroom.name %> 
      as 
      <%= select_tag "booked_bedrooms_attributes[#{bedroom.id}][booking_type_id]", options_for_select(bedroom.booking_types.map {|p| [p.name, p.id]}) %> 
<% end %> 
<% end %> 

但這不行。預訂得到保存，但沒有新的預訂臥室記錄。有人能告訴我什麼是錯的嗎？

我知道我可以使用formtastic或一些fields_for，但我想解決硬編碼形式的問題，用於演示目的。

Answer 1

我相信它應該像

<%= check_box_tag "booking[booked_bedrooms_attributes][][bedroom_id]", 
    bedroom.id %> 

<%= select_tag "booking[booked_bedrooms_attributes][][booking_type_id]", 
    options_for_select(bedroom.booking_types.map {|p| [p.name, p.id]}) %>