Ruby on rails 3 如果表单验证失败，则不会显示多个的nester属性

如果表单验证失败，则具有多个关联的字段将从视图中消失：

我的新动作看起来像

def new
  @realty = Realty.new
  @realty.build_user
  @realty.build_address
  #user, address are has_one association, and they stay in view after failed validation
  6.times { @realty.realty_images.build } # and this one vanishes away 
  respond_to do |format|
    format.html # new.html.erb
    format.json { render json: @realty }
  end
end

如果我在表单中添加此代码段

-  if @realty.realty_images.empty?
  - 6.times { @realty.realty_images.build }

字段再次显示，但有点粗糙

我试过了

6.times { @realty.realty_images.build } if @realty.realty_images.empty?

或

在控制器中，但它不工作，验证失败时字段再次消失

创建操作：

def create
    @realty = Realty.new(params[:realty]) 
    respond_to do |format|
      if @realty.save
        format.html { redirect_to @realty, notice: 'Realty was successfully created.' }
        format.json { render json: @realty, status: :created, location: @realty }
      else
        format.html { render action: "new" }
        format.json { render json: @realty.errors, status: :unprocessable_entity }
      end
    end
 end

我的表格

= simple_form_for(@realty) do |f|
  = f.error_notification

  .form-inputs
    = f.input :offer_type
    = f.input :realty_type
    = f.input :rent_type
    = f.input :price
    = f.input :description
    = f.input :state, as: :hidden
    = f.input :number_of_rooms
    = f.input :floor
    = f.input :service, as: :hidden
    = f.simple_fields_for :address do |address_f|
      = address_f.input :city, :required => true
      = address_f.input :state, :required => true
      = address_f.input :street, :required => true
    - unless user_signed_in?
      = f.simple_fields_for :user do |user_f|  
        = user_f.input :name, :autofocus => true, :required => true
        = user_f.input :phone, :required => true
        = user_f.input :email, :required => true
        = user_f.input :password, :required => true
        = user_f.input :password_confirmation, :required => true
    -  if @realty.realty_images.empty?
      - 6.times { @realty.realty_images.build } 
    = f.simple_fields_for :realty_images do |image_f|
      = image_f.input :image, as: :file

  .form-actions
    = f.button :submit

不动产模型

class Realty < ActiveRecord::Base
  attr_accessible :description, :floor, :user_id, :number_of_rooms, :price, :service, :state, :realty_images_attributes, :address_attributes, :user_attributes, :offer_type, :realty_type, :rent_type

  belongs_to :user, :dependent => :destroy, :class_name => "User"
  has_many :realty_images, :dependent => :destroy
  has_one :address, :dependent => :destroy

  validates :offer_type, :presence => true, :length => { :in => 1..256 }
  validates :realty_type, :presence => true, :length => { :in => 1..256 }
  validates :state, :presence => true, :length => { :in => 1..256 }
  validates :description, :length => { :maximum => 2000 }
  validates :service, :presence => true, :length => { :in => 1..256 }
  accepts_nested_attributes_for :realty_images
  accepts_nested_attributes_for :user
  accepts_nested_attributes_for :address
end

class Realty：destroy，：class\u name=>“user”
拥有多个：不动产\u图像，：dependent=>：destroy
有一个：地址，：依赖=>：销毁
验证：offer_type，：presence=>true，：length=>{:in=>1..256}
验证：realty_type，：presence=>true，：length=>{:in=>1..256}
验证：state，：presence=>true，：length=>{:in=>1..256}
验证：description，：length=>{：max=>2000}
验证：服务，：presence=>true，：length=>{:in=>1..256}
接受：realty\u图像的\u嵌套\u属性\u
接受用户的\u嵌套\u属性\u
接受地址的\u嵌套\u属性\u
结束

要使失败的对象仍然存在于#new中，如果存在旧对象，可以避免创建新对象。像这样：

@realty = || Realty.new

这样#new将使用旧的失败对象而不是新对象

对于@realty对象，它将起作用。但对于用户和地址等进一步的关联，我以前没有做过类似的事情，所以您需要自己验证

---

p、 代码依赖于即时变量，这就是为什么我关心如何保存obj。希望这能有点帮助：）

@Billy Chan谢谢你的建议，你真的帮了我。我对这个问题的解决方案有点粗糙，但效果很好

在创建操作中添加

6.times { @realty.realty_images.build } if @realty.realty_images.empty?

if@realty.save返回false

看起来像这样

 def create
    @realty = Realty.new(params[:realty]) 
    @realty.user = current_user if user_signed_in?
    respond_to do |format|
      if @realty.save
        format.html { redirect_to @realty, notice: 'Realty was successfully created.' }
        format.json { render json: @realty, status: :created, location: @realty }
      else
        6.times { @realty.realty_images.build } if @realty.realty_images.empty?
        format.html { render action: "new" }
        format.json { render json: @realty.errors, status: :unprocessable_entity }
      end
    end
  end

---

我认为你混淆了两个动作：新建和创建。只有当在/Realths/NeXT中访问空白窗体时才调用“新建”操作。提交表单时会调用“创建”操作

仅在“新建”操作中添加6个示例图像。在创建操作中，

Realty.new

将丢弃空白（未填充）的图像。这就是为什么你会看到他们消失。您需要在验证错误时重新添加它们。您可以将公共设置提取到一个方法中：

class RealtiesController
  def new
    @realty = Realty.new
    @realty.populate
  end

  def create
    @realty = Realty.new(params[:realty])
    if @realty.save
      # ...
    else
      @realty.populate
      render 'new'
    end
  end
end

class Realty
  # you could also place it in the controller
  # if you feel it fits better there
  def populate
    6.times{ self.realty_images.build }
  end
end

---

请展示#创建，这是关键。我把它添加到我的问题中。但这是相当标准的：）似乎不好。你没有逻辑在create中保存用户、地址和图像？我删除了这个剪掉的“@realty.user=current\u user if user\u signed\u in？”因为在这个问题中不需要它。事实上，验证失败后的地址和用户字段是存在的，如果验证通过，创建操作将创建所有必要的字段。稍后我将为此编写测试，因为它对我来说有点新，但我在rails控制台和realty.user中调试它，realty.address显示有效的用户和地址它接受\u嵌套的属性\u for:realty\u图像接受\u嵌套的属性\u for:user接受\u嵌套的属性\u for:address你是说@realty | |=realty.new？这并不能解决问题。我只有接受嵌套属性的问题：realty\u images字段，在验证失败后它们消失，所有其他字段都保留在那里。谢谢你的帮助。我已经将应用程序部署到我的VPS，您可以在这里查看@AndreyAsinishyn，我以前没有类似的案例。但我认为解决方案是使用一个image实例来构建表单，并保留此实例不变，并在创建失败时交付给#new if#create。你是什么意思？如何实现这一点？可能使用我在view“6.times{@realty.realty\u images.build}if@realty.realty\u images.empty”中的粗略方法？然后像噩梦一样忘记它？你的意思是像这样

def create…。if@realty.save…。否则6.times{@realty.realty\u images.build}如果@realty.realty\u images.empty？…end

原则上，这解决了问题。请将其添加为答案。这通常是相同的，但更优雅的方法。这是可行的，但与realty\u images表单字段相关的验证错误不会显示：（是的，它们与主模型（realty）是分开的。您必须获取并显示每个模型的realty_image.errors。

class RealtiesController
  def new
    @realty = Realty.new
    @realty.populate
  end

  def create
    @realty = Realty.new(params[:realty])
    if @realty.save
      # ...
    else
      @realty.populate
      render 'new'
    end
  end
end

class Realty
  # you could also place it in the controller
  # if you feel it fits better there
  def populate
    6.times{ self.realty_images.build }
  end
end