RoR-在多对多联接表上创建记录

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视图上，我创建了<%= link_to "New Establishment", new_client_address_path(@client)%> ，以便为客户端创建新的地址记录和新的Establishment。

在AddressController我有：

def new
        @client = Client.find(params[:client_id])
        @address = @client.addresses.build
      end


  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

这将创建新的地址，但不会创建新的场所。 这样可以自动创建将Client和Address链接起来的新场所吗？ 在您问之前，我真的需要使用此Establishment模型。

Answer 1

这里：

在您的模型中：

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

在您看来：

<%= 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 %>

你们都准备好了！！

Answer 2

首先是第一件事-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

我将解释如何传递所需的数据，但首先让我解释如何正确执行此操作：

-

收集资料

如果要通过连接表将两个现有对象关联起来，则可以使用ActiveRecord中的某些collection方法 ，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 %>

这将填充Client模型中的[other]_ids方法，从本质上将填充has_many :through连接模型。

仅当您具有已经希望与新创建的Client关联的Establishment记录时，此方法才起作用。

-

嵌套属性

如果要创建新的Establishment记录，则必须将数据发送到Address模型， 然后再发送到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

这将使您可以致电：

#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形式：

#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 %>