Question

如果表单验证失败，则has_many关联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

如果我将此代码段添加到我的表单

-  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

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

或

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

在控制器中，但它不起作用，并且在验证失败时字段会再次消失。

创建行动：

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

my -form

= 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

房地产模型

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

Answer 1

要保持失败的对象仍然存在于#new中，您可以避免在旧的对象存在时创建新对象。像这样：

@realty = || Realty.new

这样#new将使用旧的失败对象而不是新的。

对于@realty对象，它会起作用。但是对于用户和地址等进一步的关联，我之前没有做过类似的事情，所以你需要自己验证它。

p.s代码依赖于即时变量，这就是我担心如何保存obj的原因。希望这可能有点帮助：）

Answer 2

我认为你混淆了两个动作：new和create。仅在访问/ realties / new中的空白表单时才会调用“新”操作。并且在提交表单时会调用“创建”操作。

仅在“新”操作中添加6个样本图像。在创建操作中，Realty.new将丢弃空白（未填写）的图像。这就是为什么你会看到它们消失的原因。您需要在验证错误时重新添加它们。您可以将常用设置提取到方法中：

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

Answer 3

@Billy Chan感谢您的建议，您真的很帮助我。我对这个问题的解决方案有点粗糙，但效果很好

在创建动作中添加

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

如果@ 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

如果表单验证失败，则不显示has_many的nester属性

3 个答案: