Ruby on rails Rails：在嵌套模型形式中使用接受嵌套属性

在我的应用程序中，用户有许多对话，对话有许多消息。我想创建一个新的对话：我必须指定用户（读者）和（第一条）消息。我尝试了以下方法，但失败了

模型

class Conversation < ActiveRecord::Base

  has_many :conversation_users
  has_many :users, :through => :conversation_users

  has_many :messages

  accepts_nested_attributes_for :users
  accepts_nested_attributes_for :messages

end

class Message < ActiveRecord::Base

  belongs_to :conversation
  belongs_to :user

end

class User < ActiveRecord::Base

  has_many :conversation_users
  has_many :conversations, :through => :conversation_users

end

看法

这是rails服务器的响应：

Started POST "/users/8/conversations" for 127.0.0.1 at Sun Jul 17 23:58:27 +0200 2011
  Processing by ConversationsController#create as HTML
  Parameters: {"commit"=>"Submit", "authenticity_token"=>"z6kL+NmVspgCKMr9whcw+a85mA59j3jssS9QeTiEbxc=", "utf8"=>"✓", "conversation"=>{"users_attributes"=>{"0"=>{"id"=>"9"}, "1"=>{"id"=>"10"}}, "messages_attributes"=>{"0"=>{"content"=>"freee"}}}, "user_id"=>"8"}
  User Load (0.3ms)  SELECT "users".* FROM "users" INNER JOIN "conversation_users" ON "users".id = "conversation_users".user_id WHERE "users"."id" IN (9, 10) AND (("conversation_users".conversation_id = NULL))

ActiveRecord::RecordNotFound (Couldn't find User with ID=9 for Conversation with ID=):
  app/controllers/conversations_controller.rb:26:in `new'
  app/controllers/conversations_controller.rb:26:in `create'

对话的第26行\u控制器：

@conversation=conversation.new（参数[：conversation]）

我怎样才能让它工作

谢谢。

更换：

   <% f.fields_for :users do |builder| %>

与：

同样丢失的“=”稍微低一点。

<% form_for([current_user, @conversation]) do |f| %>

应该是

<%= form_for([current_user, @conversation]) do |f| %>

<%= f.fields_for :messages do |builder| %>
# and
<%= f.fields_for :users do |builder| %>

及

#及

应该是

<%= form_for([current_user, @conversation]) do |f| %>

<%= f.fields_for :messages do |builder| %>
# and
<%= f.fields_for :users do |builder| %>

#及

和形式

<%= form_for([current_user, @conversation]) do |f| %>
  <%= f.fields_for :conversation_users do |builder| %>    
    <%= builder.text_field :user_id %>
    <%= builder.hidden_field :conversation_id %>
  <% end %>
  ...
<% end %>

...

---

就这样。

你说的“失败”是什么意思？有错误吗？我添加了错误回复。。。这是一个未找到的记录错误我在你的回答中看不到任何错误什么是

当前\u用户名

？show this helper codeccurrent\u username是当前登录用户的用户名。current_user返回当前登录的用户（在这两种情况下，都是创建新对话的用户）@apheading实际上反之亦然：）对，我正在创建一个新的“对话用户”对象，而不是“用户”对象！太好了：）谢谢你的帮助

<% f.fields_for :messages do |builder| %>
# and
<% f.fields_for :users do |builder| %>

<%= f.fields_for :messages do |builder| %>
# and
<%= f.fields_for :users do |builder| %>

class Conversation < ActiveRecord::Base
  has_many :conversation_users
  has_many :users, :through => :conversation_users
  has_many :messages
  # NEXT LINE IS CHANGED!
  accepts_nested_attributes_for :conversation_users
  accepts_nested_attributes_for :messages
end

def new
  @conversation = Conversation.new
  2.times{ users = @conversation.conversation_users.build }
  messages = @conversation.messages.build
end

<%= form_for([current_user, @conversation]) do |f| %>
  <%= f.fields_for :conversation_users do |builder| %>    
    <%= builder.text_field :user_id %>
    <%= builder.hidden_field :conversation_id %>
  <% end %>
  ...
<% end %>