Question

我尝试在rails 3.2应用程序中为某些图像上传设置carrierwave_direct，但似乎无法使用direct_upload_form_for标记呈现表单。

我收到错误“未定义的方法`direct_fog_url'用于＃＆lt; PostmarkerImage：0x007fdbe07b39f0＆gt;”加载包含表单的页面时。

PostmarkerImage是我安装上传器的模型：

class PostmarkerImage < ActiveRecord::Base
  attr_accessible :image, :image_cache

  belongs_to :postmarker

  validates :image, :presence => true

  mount_uploader :image, PostmarkerImageUploader
end

image列是一个字符串，我还确保已运行迁移以创建列。上传者现在看起来像这样：

class PostmarkerImageUploader < CarrierWave::Uploader::Base
  include CarrierWaveDirect::Uploader

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

  # Include the Sprockets helpers for Rails 3.1+ asset pipeline compatibility:
  include Sprockets::Helpers::RailsHelper
  include Sprockets::Helpers::IsolatedHelper

  # Choose what kind of storage to use for this uploader:
  # storage :file
  # storage :fog

  include CarrierWave::MimeTypes
  process :set_content_type

  # Provide a default URL as a default if there hasn't been a file uploaded:
  # def default_url
  #   # For Rails 3.1+ asset pipeline compatibility:
  #   # asset_path("fallback/" + [version_name, "default.png"].compact.join('_'))
  #
  #   "/images/fallback/" + [version_name, "default.png"].compact.join('_')
  # end

  # Process files as they are uploaded:
  # process :scale => [200, 300]
  #
  # def scale(width, height)
  #   # do something
  # end

  # Create different versions of your uploaded files:
  # version :thumb do
  #   process :scale => [50, 50]
  # end

  # Add a white list of extensions which are allowed to be uploaded.
  # For images you might use something like this:
  def extension_white_list
    %w(jpg jpeg gif png)
  end

  # Override the filename of the uploaded files:
  # Avoid using model.id or version_name here, see uploader/store.rb for details.
  # def filename
  #   "something.jpg" if original_filename
  # end

end

我还确保已经安装了carrierwave_direct，fog，mini_magick和Imagemagick。我可以知道我还错过了什么吗？看起来上传器的安装似乎没有做好。

Answer 1

管理解决问题:)以防万一有人遇到此问题：

我正在实现一个单独的模型来保存我的图像，而不是将列添加到现有表中。因此，direct_upload_form_for需要列（例如Image.new.image）而不是我返回的对象（例如Image.new）。我想我被form_for部分抛弃，通常需要一个对象！

Answer 2

对于遇到此错误的任何其他人，您可能无法将正确的对象传递给direct_upload_form_for。假设我们有一个带有头像列的用户模型。它应该看起来像。

型号：

class User < ActiveRecord::Base
  mount_uploader :avatar, AvatarUploader
end

控制器：

def edit # Could be any action, but I always direct upload to existing objects
  @uploader = @user.avatar
  @uploader.success_action_redirect = edit_registration_url(resource)
end

查看（错误）：

<%= direct_upload_form_for @uploader do |f| %>
  <%= f.file_field :image %>
<% end %>

注意@uploader对象实际上是列 @ user.avatar，而不是对象 @user。这就是OP在他的回答中所说的话。在他的情况下，这更令人困惑，因为对象不是用户，它是PostmarkerImage，我假设它是一个仅存在以保存图像的模型。当您希望一个对象（即邮戳）拥有多个图像时，这种情况很常见。因此，您只为图像创建模型，并在它们之间建立has_many关系。

陷阱：我在制作中也遇到了很多错误，因为我忘记将控制器中的代码从edit操作复制到update操作。如果由于验证而导致上传失败（如文件类型），则需要记住再次设置@uploader！同样，如果您在new中有上传者，请记得在create中分配@uploader。

rails carrierwave_direct无法呈现direct_upload_form_for表单

2 个答案: