Rails - 如何设置与 class_name 的 has_many_through 关联

Question

我正在修改一个包含赞助商和成员的应用程序，并希望添加一个协会，让赞助商可以拥有许多可能是成员的联系人。成员可以是许多赞助商的联系人。这会是一个 has_many through 关系，其中联系人使用成员类吗？这是我尝试过的。

class Sponsor < ActiveRecord::Base
  has_many :member_contacts
  has_many :contacts, through: member_contacts, class_name: :member
end

class Contact < ActiveRecord::Base
  has_many :member_contacts
  has_many :sponsors, through: member_contacts
end

class MemberContact  < ActiveRecord::Base
  belongs_to :contact
  belongs_to :sponsor
end

class Member < ActiveRecord::Base
  has_many :subscriptions
  has_many :groups, through: :subscriptions
  has_many :member_notes
  has_many :chapters, -> { uniq }, through: :groups
  has_many :announcements, -> { uniq }, through: :groups
  validates_uniqueness_of :email
end

sponsors_controller.rb

class SponsorsController < ApplicationController
  def index
    @sponsors = Sponsor.joins(:sponsor_sessions).all
  end

  def new
    @sponsor = Sponsor.new
    @sponsor.contacts.build
  end
end

在 form.html.haml 中

= f.collection_select :contacts, Member.all, :id, :full_name, { selected: @sponsor.contacts.map(&:id) }, { multiple: true }

当我尝试访问 /sponsors/new 时，我得到了

'uninitialized constant Sponsor::member' 

指向sponsors_controller新方法中的行

@sponsor.contacts.build

谁能告诉我我做错了什么？

Answer 1

问题在于您的Sponsor 模型中的这一行

has_many :contacts, through: member_contacts, class_name: :member

应该是这样的

has_many :contacts, through: member_contacts, class_name: 'Member'