在我的应用中,用户有很多对话,而对话有很多消息。我想创建一个新的对话:我必须指定用户(读者)和(第一个)消息。我试过以下,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
控制器
def new
@conversation = Conversation.new
2.times do
users = @conversation.users.build
end
messages = @conversation.messages.build
end
def create
@conversation = Conversation.new(params[:conversation])
if @conversation.save
redirect_to username_conversations_path(current_username)
else
redirect_to new_username_conversation_path(current_username)
end
end
查看
<% form_for([current_user, @conversation]) do |f| %>
<% f.fields_for :users do |builder| %>
<%= builder.text_field :id %>
<% end %>
<% f.fields_for :messages do |builder| %>
<%= builder.text_area :content %>
<% end %>
<%= f.submit "Submit" %>
<% end %>
current_user和current_username是如下定义的辅助方法:
def current_user
@current_user ||= User.find(session[:user_id]) if session[:user_id]
end
def current_username
@current_username ||= current_user.username if current_user
end
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'
conversations_controller第26行:@conversation = Conversation.new(params[:conversation])
我怎样才能让它发挥作用?
感谢。
答案 0 :(得分:6)
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
控制器
def new
@conversation = Conversation.new
2.times{ users = @conversation.conversation_users.build }
messages = @conversation.messages.build
end
并形成
<%= 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 %>
就是这样。
答案 1 :(得分:1)
替换:
<% f.fields_for :users do |builder| %>
使用:
<%= f.fields_for :users do |builder| %>
同样缺少&#39; =&#39;稍低一点。
答案 2 :(得分:1)
<% form_for([current_user, @conversation]) do |f| %>
应该是
<%= form_for([current_user, @conversation]) do |f| %>
和
<% f.fields_for :messages do |builder| %>
# and
<% f.fields_for :users do |builder| %>
应该是
<%= f.fields_for :messages do |builder| %>
# and
<%= f.fields_for :users do |builder| %>