ruby-on-rails - 回形针:继续编辑

Question

当用户在我的应用程序中编辑某些内容时，即使他们没有更改图像，他们也被迫通过回形针重新上传图像。不这样做会导致错误，因为我validate_presence_of :image。这很烦人。

如果用户根本没有在编辑时提供新图像，我如何才能使 Paperclip 不会更新其属性？

光 Controller 是从 Rails 的脚手架生成器中新鲜出来的。下面提供了其余的源代码。

模型/住宿.rb

class Accommodation < ActiveRecord::Base
  attr_accessible :photo
  validates_presence_of :photo
  has_one :photo
  has_many :notifications
  belongs_to :user
  accepts_nested_attributes_for :photo, :allow_destroy => true
end

Controller /accommodation_controller.rb

class AccommodationsController < ApplicationController
  def index
    @accommodations = Accommodation.all
  end

  def show
    @accommodation = Accommodation.find(params[:id])
    rescue ActiveRecord::RecordNotFound
      flash[:error] = "Accommodation not found."
      redirect_to :home
  end

  def new
    @accommodation = current_user.accommodations.build
    @accommodation.build_photo
  end

  def create
    @accommodation = current_user.accommodations.build(params[:accommodation])
    if @accommodation.save
      flash[:notice] = "Successfully created your accommodation."
      redirect_to @accommodation
    else
      @accommodation.build_photo
      render :new
    end
  end

  def edit
    @accommodation = Accommodation.find(params[:id])
    @accommodation.build_photo
    rescue ActiveRecord::RecordNotFound
      flash[:error] = "Accommodation not found."
      redirect_to :home
  end

  def update
    @accommodation = Accommodation.find(params[:id])
    if @accommodation.update_attributes(params[:accommodation])
      flash[:notice] = "Successfully updated accommodation."
      redirect_to @accommodation
    else
      @accommodation.build_photo
      render :edit
    end
  end

  def destroy
    @accommodation = Accommodation.find(params[:id])
    @accommodation.destroy
    flash[:notice] = "Successfully destroyed accommodation."
    redirect_to :inkeep
  end

end

模型/照片.rb

class Photo < ActiveRecord::Base
  attr_accessible :image, :primary
  belongs_to :accommodation
  has_attached_file :image,
    :styles => {
      :thumb=> "100x100#",
      :small  => "150x150>" }
end

Answer 1

你不应该需要 @accommodation.build_photo除了在 new 之外的任何地方行动。