Rails :inverse_of误差

Question

class User < ActiveRecord::Base
  attr_accessible :email, :password, :picture, :username
  has_many :entries, :class_name => "Entry", :inverse_of => :user

  has_many :sent_messages, :inverse_of => :sender, :class_name => "Message", :foreign_key => "sender_id"
  has_many :recieved_messages, :inverse_of => :target, :class_name => "Message", :foreign_key => "target_id"

  has_many :mails, :inverse_of => :user
  ...
end

class Message < ActiveRecord::Base
  attr_accessible :message, :seen, :title
  belongs_to :sender, class_name => "User", :inverse_of => :sent_messages
  belongs_to :target, class_name => "User", :inverse_of => :recieved_messages
end

class CreateMessages < ActiveRecord::Migration
  def change
    create_table :messages do |t|
      t.references :sender
      t.references :target
      t.string :title
      t.string :message
      t.boolean :seen

      t.timestamps
    end
  end
end

我有这两个模特。当我试图获取用户发送的消息(user.sent_messages)时，会收到如下错误：

Could not find the inverse association for sent_messages (:sender in Message)

这是我使用Rails的第二天，所以这可能很简单，但我没有看到。

PS:如果我从类用户中删除:inverse_of =>：:inverse_of，user.sent_messages可以工作，但据我所知，：inverse_of很重要。

PPS:发现错误！在消息类中，我使用的是class_name而不是:class_name.。

Answer 1

这就是为什么我喜欢在可能的情况下使用新样式的散列。

class Message < ActiveRecord::Base
attr_accessible :message, :seen, :title
belongs_to :sender, class_name: 'User', inverse_of: :sent_messages
belongs_to :target, class_name: 'User', inverse_of: :recieved_messages
end

虽然和很多事情一样，这往往是个人品味的问题:)