ruby-on-rails-3 - Carrierwave：设置图片路径并跳过上传

Question

我想设置一些图像而不上传。（它们已经存在，或者另一个任务保存了它们......）

如果我尝试（在 Rails 控制台中）：

user = User.last
user.picture = '/some/picture.jpg'
user.save
user.picture # nil

唯一的方法是设置remote_picture_url，然后删除上传（这很愚蠢）

在carrierwave中是否有任何方法可以让您只修改文件名？

Answer 1

class User < ActiveRecord::Base
  attr_accessible :picture
  # Don't want to write to the database, but want to be able to check
  attr_writer :skip

  # set a default value
  def skip
   @skip ||= false
  end

  mount_uploader :image, PictureUploader

  # Make sure that the skip callback comes after the mount_uploader
  skip_callback :save, :before, :store_picture!, if: :skip_saving?

  # Other callbacks which might be triggered depending on the usecase
  #skip_callback :save, :before, :write_picture_identifier, id: :skip_saving?

  def skip_saving?
    skip
  end
end

class PictureUploader < Carrierwave::Uploader::Base
  # You could also implement filename=
  def set_filename(name)
    @filename = name
  end
end

假设你有上面的设置，在你的控制台中：

user = User.last
user.picture.set_filename('/some/picture.jpg')
user.skip = true
# Save will now skip the callback store_picture!
user.save
user.picture # /some/picture.jpg

应该注意的是，如果您在控制台中并更新具有附加文件（即 user.picture.file）的现有记录，它将显示旧的 url/位置。如果您退出控制台（假设您未处于沙盒模式）并返回并查询相同的对象，它将具有更新的 url/位置。