铁路2：has_many：通过验证？

Question

Rails 2.1.0（由于几个约束，目前无法升级）我正在尝试实现这一目标。有提示吗？

1. 一个项目通过加入模型有许多用户
2. 用户通过加入模型有许多项目
3. 管理类继承用户类。它还具有一些管理特定的内容。
4. 管理员和管理者的继承类似
5. 项目有一名管理员，一名主管和许多运营商。

现在，我要1.在单个项目表2中提交项目，管理员，主管和运营商的数据2.验证所有内容并在项目表格上显示错误。

Project has_many :projects_users ; has_many :users, :through => :projects_users
User has_many :projects_users ; has_many :projects, :through => :projects_users
ProjectsUser = :id integer, :user_id :integer, :project_id :integer
ProjectUser belongs_to :project, belongs_to :user
Admin < User # User has 'type:string' column for STI
Supervisor < User
Operator < User

方法正确吗？欢迎所有建议。

Answer 1

我最终使用了管理员，主管和运营商的虚拟属性

Answer 2

我猜单个表格和嵌套表格可能会在这里为您提供帮助。您可能想在文档中阅读有关它的信息。 http://api.rubyonrails.org/classes/activerecord/base.html

Answer 3

我发现答案在于用has_many的单个表继承：

class Project < ActiveRecord::Base
  has_many :projects_users, :dependent => :destroy
  has_many :users, :through => :projects_users, :dependent => :destroy
  has_one :admin, :through => :projects_users, :source => :user, :conditions => {:type => "Admin"}
  has_one :supervisor, :through => :projects_users, :source => :user, :conditions => {:type => "Supervisor"}
  has_many :operators, :through => :projects_users, :source => :user, :conditions => {:type => "Operator"}
  validates_presence_of :name
  validates_associated :admin

  def admin_attributes=(attributes)
    # build an admin object and apply to this relation
  end

  def supervisor_attributes=(attributes)
    # build a supervisor object and apply to this relation
  end

  def operator_attributes=(operator_attributes)
    operator_attributes.each do |attributes|
      # build an operator object for each set of attributes and apply to this relation
    end
  end
end

class User < ActiveRecord::Base
  has_many :projects_users, :dependent => :destroy
  has_many :projects, :through => :projects_users, :dependent => :destroy
  validates_presence_of :name
  validates_associated :projects
end

class ProjectsUser < ActiveRecord::Base
  belongs_to :project
  belongs_to :user
end

class Admin < User
end

class Supervisor < User
end

class Operator < User
end

现在我们可以有以下内容

project1.users # User objects for admin, supervisor and operators
project1.admin # User object for Admin
project1.supervisor # User object for Supervisor
project1.operators # User objects for Operator

包括所有这些都可以有的复杂形式

<% form_for :project ...
    <% fields_for "project[admin_attributes]", @project.admin do |admin_form|
    ...
    <% @project.operators.each do |operator| %>
        <% fields_for "project[operator_attributes][]", operator do |operator_form| %>

等等...