Question

我使用has_many：through建立了一个自我参照联盟，基本上就像这个Railscast：http://railscasts.com/episodes/163-self-referential-association所描述的那样。

某些“活动”有点像“文章”，并且有一组相关的其他活动，因此命名了连接表。这有点令人困惑......我知道。

我很难把事情做好保存。这就是我所拥有的......

activity.rb

class Activity < ActiveRecord::Base
  has_many :article_activities
  has_many :activities, :through => :article_activities
  accepts_nested_attributes_for :activities
end

article_activity.rb

class ArticleActivity < ActiveRecord::Base
  attr_accessible :article_id, :activity_id
  belongs_to :activity
  belongs_to :article, :class_name => "Activity"
end

articles_controller.rb

class ArticlesController < ApplicationController

  def new
    @activity = Activity.new
    @activity.is_article = true
    @user_activities = current_user.activities
  end

  def create
    @activity = Activity.new params[:activity]
    @activity.is_article = true
    @activity.user = current_user

    if @activity.save
      redirect_to root_path, :notice => "Article created!"
    else
      render :action => "new"
    end
  end

new.html.haml

= simple_form_for @activity, :url => articles_path do |f|
  / Other fields omitted for clarity
  = f.association :activities, :collection => @user_activities

因此，在提交表单后，@activity操作中的create具有预期的@activity.activities。但是，在保存@activity并重新加载记录后，@activity.activities为空。

如何保存关联的任何想法？

Answer 1

我想出了这个。我不得不在模型中添加：foreign_key作为“文章”......

class ArticleActivity < ActiveRecord::Base
  attr_accessible :article_id, :activity_id
  belongs_to :activity
  belongs_to :article, :class_name => "Activity", :foreign_key => "article_id"
end

class Activity < ActiveRecord::Base
  belongs_to :user
  has_many :article_activities, :foreign_key => "article_id"
  has_many :activities, :through => :article_activities 
end

如何保存has_many：通过自我引用关联

1 个答案: