Rails 3中私有消息建模的首选方法

Question

我计划在成员之间实现私人消息系统.我想知道什么是首选方法.

要求是

1. 我应该可以像这样轻松地检索它们

   @user.conversations               #Should return User objects that I sent or received messages from (but not me)
   @user.conversations.messages      #Messages from all or specific user objects.
   @user.conversations.messages.unread      #Unread messages
   

2. 当调用@ user.conversations时,应仅检索向我发送消息的人或我发送消息的人.应排除current_user.

3. 如果我是sender_id = 5并发送to_id = 10那么,另一个人将回复发送者= 10 to_id = 5.这应该被视为并理解为相同的会话对象.

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关于最后一点.我不确定什么是首选的建模方法.

最好使用一个Conversation模型来处理所有消息,例如

    attr_accessible :user_id, :friend_id, :message, :read
    belongs_to :user

或者,最好创建一个Conversation模型来处理关联和消息的Message模型.

我想看看如何实现这种关系的示例案例,以及是否有其他方法可以实现.

我在这里有点失落.

Answer 1

一个更简单的模型是捕获每个消息:

class Message < ActiveRecord::Base
  belongs_to :from_user,  :class_name => 'User' # from_user_id field fk Users
  belongs_to :to_user,    :class_name => 'User' # to_user_id field fk Users
  belongs_to :thread, :class_name => 'Message'  # Reference to parent message
  has_many :replies,  :class_name => 'Message', :foreign_key => 'thread_id'

  named_scope :in_reply_to, lambda { |message| :conditions => {:thread => message}, :order => 'created_at' }
end

class User < ActiveRecord::Base
  has_many :messages_received,  :class_name => 'Message', :foreign_key=> 'to_user_id'
  has_many :messages_sent,      :class_name => 'Message', :foreign_key=> 'from_user_id'
end

如果您需要捕获消息线程,那么任何回复消息都可以存储对开始对话(又称为线程)的初始消息的引用.例如:

first_msg   = Message.new(:to_user => bob, :from_user => sally, :body => 'Hello!')
sally_reply = first_msg.replies.build(:to_user => bob, :from_user => sally, :body => 'hi back')
bob_reply   = first_msg.replies.build(:to_user => sally, :from_user => bob, :body => 'later')