軌道4的has_many通過 - 消息發送者接收與

Question

我試圖實現以下，關係和對象調用

用戶可以發送許多消息（user.sent_messages） 一個消息可以具有一個發送器（消息。發送者）

用戶可以接收許多消息（user.received_messages） 一個消息可以具有許多接收器（message.receivers）

我的模式是這樣的：

create_table "activities", force: true do |t| 
t.integer "sender_id" 
t.integer "message_id" 
t.datetime "created_at" 
t.datetime "updated_at" 
t.integer "receiver_id" 
end 

create_table "messages", force: true do |t| 
t.text  "body" 
t.datetime "created_at" 
t.datetime "updated_at" 
t.boolean "read",  default: false 
end 

個

我的模型是這樣的：

class User < ActiveRecord::Base 
has_many :activities, class_name: 'Activity', foreign_key: 'sender_id', dependent: :destroy 
has_many :sent_messages, through: :activities 

has_many :reverse_activities, class_name: 'Activity', foreign_key: 'receiver_id' 
has_many :received_messages, through: :reverse_activities 
end 

class Activity < ActiveRecord::Base 
belongs_to :sent_messages, class_name: 'User' 
belongs_to :received_messages, class_name: 'User' 
belongs_to :message 
end 

class Message < ActiveRecord::Base 
has_many :activities, foreign_key: 'sender_id' 
has_one :sender, through: :activities, foreign_key: 'sender_id', class_name: 'User' 

has_many :reverse_activities, foreign_key: 'receiver_id', class_name: 'User' 
has_many :receivers, through: :reverse_activities, source: :receiver 

end 

方法sent_messages & received_messages工作，但是它們指向直接返回給用戶表並返回該用戶，而不是信息的細節。

我還沒有試圖讓消息模型工作，因爲用戶模型是不正確的。

謝謝！

---

由於這兩個建議，我已經得到了以下工作

class User < ActiveRecord::Base 

has_many :activities, class_name: 'Activity', foreign_key: 'sender_id' 
has_many :sent_messages, through: :activities, foreign_key: 'message_id', class_name:  'Message', source: :sender 

has_many :reverse_activities, class_name: 'Activity', foreign_key: 'receiver_id' 
has_many :received_messages, through: :reverse_activities, foreign_key: 'message_id', class_name: 'Message', source: :receiver 
end 

class Message < ActiveRecord::Base 
has_one :sent_activities, class_name: 'Activity', foreign_key: 'message_id' 
has_one :sender, through: :sent_activities, foreign_key: 'sender_id', class_name: 'User' 

has_many :receiver_activities, class_name: 'Activity', foreign_key: 'message_id' 
has_many :receivers, through: :receiver_activities, foreign_key: 'receiver_id', class_name: 'User' 

validates :body, presence: true 
end 

class Activity < ActiveRecord::Base 
belongs_to :sender, class_name: 'User' 
belongs_to :receiver, class_name: 'User' 
belongs_to :receiver, class_name: 'Message' 
belongs_to :sender, class_name: 'Message' 
end 

根據需要方法的我正在努力的結果。

現在只是爲了讓創建操作工作！

Answer 1

有一些失誤模式消息：

class Message < ActiveRecord::Base 

不應該foreign_key是： 「MESSAGE_ID」？在foreign_key

has_many :activities, foreign_key: 'sender_id' 

同樣的問題：「SENDER_ID」，和其他可能的事情在以下

has_one :sender, through: :activities, foreign_key: 'sender_id', class_name: 'User' 

has_many :reverse_activities, foreign_key: 'receiver_id', class_name: 'User' 
has_many :receivers, through: :reverse_activities, source: :receiver 

end 

你看起來像使用消息的ID加入到其他表的發件人ID和接收ID。

class Activity < ActiveRecord::Base 

類名是「用戶」，所以sent_messages，received_messages返回用戶信息

belongs_to :sent_messages, class_name: 'User' 
belongs_to :received_messages, class_name: 'User' 
belongs_to :message 
end 

希望它能幫助。

Answer 2

太複雜

你爲什麼不試試這個：

#app/models/message.rb 
Class Message < ActiveRecord::Base 
    belongs_to :sender, class_name: "User", primary_key: "sender_id" 
    belongs_to :recipient, class_name: "User", primary_key: "recipient_id" 
end 

#app/models/user.rb 
Class User < ActiveRecord::Base 
    has_many :sent_messages, class_name: "Message", foreign_key: "sender_id" 
    has_many :received_messages, class_name: "Message", foreign_key: "recipient_id" 
end 

users 
id | name | email | created_at | updated_at 

messages 
id | sender_id | recipient_id | title | body | created_at | updated_at 

這將允許您加載這樣的數據：

@message.sender 
@message.recipient 

@user.sent_messages 
@user.received_messages 

要保存的數據，你可以使用：

#app/controllers/messages_controller.rb 
def new 
    @message = Message.new 
end 

def create 
    @message = Message.new(message_params) 
end 

private 

def message_params 
    params.require(:message).permit(:recipient_id, :title, :body).merge(sender_id: current_user.id) 
end 

#app/views/messages/new.html.erb (user has to be logged in) 
<%= form_for @message do |f| %> 
    <%= f.collection_select(:recipient_id, User.all, :id, :name) %> 
    <%= f.text_field :title %> 
    <%= f.text_area :body %> 
    <%= f.submit %> 
<% end %>