RoR - 在多对多连接表上创建记录

Question

我有以下型号：

Client.rb
  has_many :establishments
  accepts_nested_attributes_for :establishments

  has_many :addressess, through: :establishments
  accepts_nested_attributes_for :addresses


Establishment.rb
  belongs_to :address
  belongs_to :client


Address.rb
  has_many :establishments 

在Client 的show 视图中，我创建了一个<%= link_to "New Establishment", new_client_address_path(@client)%>，以便为客户创建一个新的地址记录和一个新的机构。

在AddressController 我有：

定义新 @client = Client.find(params[:client_id]) @address = @client.addresses.build 结尾

  def create
    @address = Address.new(address_params)

    respond_to do |format|
     if @address.save
      format.html { redirect_to @address, notice: 'Estabelecimento criado com sucesso.' }
      format.json { render action: 'show', status: :created, location: @address }
     else
      format.html { render action: 'new' }
      format.json { render json: @address.errors, status: :unprocessable_entity }
     end
    end
   end

这将创建新地址，但不会创建新机构。这可以自动创建链接Client 和Address 的新机构吗？在你问之前，我真的需要这个Establishment 模型。

Answer 1

首先 - 您将无法使用 accepts_nested_attributes_for :addresses 调用 - 您只能通过直接连接的模型传递关联数据

我会解释如何传递你想要的数据，但首先让我解释一下如何正确地做到这一点：

--

收集数据

如果你想通过一个连接表关联两个现有对象，你可以使用collection methods in ActiveRecord中的一些，即other_ids

#app/views/clients/new.html.erb
<%= form_for @client do |f| %>
   <%= f.collection_select :establishment_ids, Establishment.all, :id, :name %>
   <%= f.submit %>
<% end %>

这将在您的Client 模型中填充[other]_ids 方法，该方法实质上将填充您拥有的has_many :through 连接模型。

这只有在您已经希望将Establishment 记录与新创建的Client 关联时才有效。

--

嵌套属性

如果您想创建一个新的Establishment 记录，您必须将数据发送到Address 模型，然后然后 发送到Establishment 模型：

#app/models/client.rb
class Client < ActiveRecord::Base
   has_many :establishments
   has_many :addresses, through: :establishments
end

#app/models/establishment.rb
class Establishment < ActiveRecord::Base
   belongs_to :client
   belongs_to :address
   accepts_nested_attributes_for :address
end

#app/models/address.rb
class Address < ActiveRecord::Base
   has_many :establishments
   has_many :clients, through: :establishments
end

这将允许您调用：

#app/controllers/clients_controller.rb
class ClientsController < ApplicationController
   def new
     @client = Client.new
     @client.establishments.build.build_address
   end

   def create
      @client = Client.new client_params
      @client.save
   end

   private 

   def client_params
      params.require(:client).permit(establishments_attributes: [address_attributes:[]])
   end
end

这将允许您使用以下表格：

#app/views/cients/new.html.erb
<%= form_for @client do |f| %>
   <%= f.fields_for :establishments do |e| %>
      <%= e.fields_for :address do |a| %>
         ...
      <% end %>
   <% end %>
   <%= f.submit %>
<% end %>

Answer 2

这里：

在你的模型中：

Client.rb
  has_many :establishments
  accepts_nested_attributes_for :establishments

  has_many :addresses, through: :establishments
  accepts_nested_attributes_for :addresses


Establishment.rb
  belongs_to :address
  belongs_to :client


Address.rb
  has_many :establishments
  has_many :clients, through: :establishments

在您的控制器中：

class AddressController < ApplicationController

  def new
    @client = Client.find(params[:client_id])
    @client.establishments.build.build_address
    # if you have a column in establishment, for example: name
    # you can do something like this to set establishment's name:
    # @client.establishments.build(name: 'First connection').build_address
  end

  # create method doesn't need to be changed!!

end

在你看来：

<%= form_for(@client) do |form| %>
  <%= form.input :name %>

  <%= form.fields_for(:establishments) do |establishment_form| %>
    <% establishment = establishment_form.object.name.titleize %>
    <%= establishment_form.input :name, as: :hidden %>
    <%= establishment_form.fields_for(:address) do |address_form| %>
      <%= address_form.input :address1, label: "#{establishment} address1" %>
      <%= address_form.input :address2, label: "#{establishment} address2" %>
    <% end %>
  <% end %>

  <%= form.submit "Submit" %>
<% end %>

一切准备就绪！