rails carrierwave default_url无效

Question

我不认为我正确理解这一点,但我如何为用户提供默认图像？

   def default_url
      "/images/fallback/" + [version_name, "default.png"].compact.join('_')
   end

我的images/fallback目录中有一个名为'default.png'的图像.我在网上看到人们也将版本名称更改为"微小",但这对我来说似乎也不起作用.这是怎么回事？版本名称究竟是什么？

我尝试过类似的东西

   def default_url
      "/images/fallback/default.png"
   end

但这也不起作用.我有什么误会？谢谢!

编辑:

class ImageUploader < CarrierWave::Uploader::Base

  # Include RMagick or MiniMagick support:
  include CarrierWave::RMagick

  storage :file

  def store_dir
    "uploads/#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}"
  end

  # Provide a default URL as a default if there hasn't been a file uploaded:
   def default_url
      ???????
   end

  # Create different versions of your uploaded files:
   version :thumb do
     process :resize_to_fill => [80, 80]
   end

end





class User < ActiveRecord::Base
  # Include default devise modules. Others available are:
  # :token_authenticatable, :encryptable, :confirmable, :lockable, :timeoutable and :omniauthable
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :validatable

  # Setup accessible (or protected) attributes for your model
  attr_accessible :name, :email, :password, :password_confirmation,
     :remember_me, :image, :remote_image_url, :image_cache

  mount_uploader :image, ImageUploader
end

Answer 1

如果您正在使用资产管道,那么您不需要在文件路径中包含"images",因为image_tag它将自动路由到该assets/images文件夹,然后在那里查找文件名.因此,default_url方法中需要的路径是images文件夹之后的路径.在我的情况下,它只是default.png,因为我在images文件夹中没有子文件夹.

    def default_url
       'default.png'
    end

Answer 2

例如,你有这样的上传者:

class MyUploader < CarrierWave::Uploader::Base

  version :thumb do
    process resize_to_fill: [280, 280]
  end

  version :small_thumb, :from_version => :thumb do
    process resize_to_fill: [20, 20]
  end

   def default_url
      "/images/fallback/" + [version_name, "default.png"].compact.join('_')
   end
end

/images/fallback/default.png代表原始图像,small_thumb版本路径是/images/fallback/small_thumb_default.png,等等.

如果您想要处理后图像实际保存的路径,则需要 store_dir

  def store_dir
    'public/my/upload/directory'
  end