ruby-on-rails - 通过 Active Admin 使用 HABTM 或 Has_many

Question

我已经阅读了很多关于通过关联将事件管理员与 has_many 结合使用的帖子，但我没有得到想要的结果。基本上我有 2 个模型“ session ”和“帐户”。我需要为一个 session 分配多个帐户，为一个帐户分配多个 session 。我是否使用 HABTM 或 has_many through 对我来说并不重要。我只需要能够在创建新 session 时看到下拉选择选项，反之亦然。

账户模型

class Account < ActiveRecord::Base
  attr_accessible :address, :city, :name, :phone, :state, :website, :zip
  has_many :contacts, :dependent => :destroy
  has_many :conferences, :through => :conferenceaccount
end

session 模型

class Conference < ActiveRecord::Base
  attr_accessible :address, :city, :conferencename, :eventdateend, :eventdatestart, :industry, :phone, :state, :website
  has_many :accounts, :through => :conferenceaccount
end

session 账号模型

class Conferenceaccount < ActiveRecord::Base
  belongs_to :conference
  belongs_to :account

  attr_accessible :account_id, :conference_id
end

session 管理模式

ActiveAdmin.register Conference do 
  form do |f|
      f.inputs "Details" do # Project's fields
          f.input :conferencename
          f.input :address
          f.input :city
          f.input :state         
          f.input :website
          f.input :phone
          f.input :eventdatestart
          f.input :eventdateend
          f.input :industry         
      end
      f.has_many :conferenceaccounts do |app_f|
         app_f.inputs "Conferences" do
           if !app_f.object.nil?
             # show the destroy checkbox only if it is an existing appointment
             # else, there's already dynamic JS to add / remove new appointments
             app_f.input :_destroy, :as => :boolean, :label => "Destroy?"
           end

           app_f.input :account # it should automatically generate a drop-down select to choose from your existing patients
         end
       end      
      f.buttons
  end
end

我不断收到以下错误

ActionView::Template::Error (undefined method `klass' for nil:NilClass):
    1: insert_tag renderer_for(:new)
  app/admin/conferences.rb:14:in `block (2 levels) in <top (required)>'

我怎样才能解决这个问题？

谢谢。

Answer 1

您是否尝试将以下几行添加到您的 session 模型中？

# conference.rb
attr_accessible : conferenceaccounts_attributes
has_many :conferenceaccounts

# This line after your your relations
accepts_nested_attributes_for : conferenceaccounts, :allow_destroy => true

见:accept nested attributes for has_many relationship