Rails 回形针图像保存答案

【问题标题】：Rails paperclip image saveRails 回形针图像保存
【发布时间】：2011-11-11 15:56:54
【问题描述】：

使用回形针时，如果我尝试像这样输入网址（在图片保存后的创建函数中

image = Magick::ImageList.new('public' + @picture.photo.url)

我得到了错误

Magick::ImageMagickError in PicturesController#create

no decode delegate for this image format `public/system/photos/115/original/Kitchener-2011103100531.jpg?1321026621' @ error/constitute.c/ReadImage/532

如果我尝试进入

@picture.latitude = EXIFR::JPEG.new('public' + @picture.photo.url).gps_lat

只处理我得到的 exif 数据

Errno::ENOENT in PicturesController#create

No such file or directory - public/system/photos/116/original/Kitchener-20111031-00531.jpg?1321026744

当我尝试在 rails 控制台中执行 photo.url 时，它提供了良好的格式，但在我的控制器中最后添加了一些奇怪的垃圾“？1321026621”。我该如何解决？（一个正则表达式看起来很容易解决这个问题，但有没有比这更好的方法）

【问题讨论】：

标签： ruby-on-rails imagemagick paperclip exif

【解决方案1】：

来自paperclip github project：

https://github.com/thoughtbot/paperclip/blob/master/lib/paperclip/attachment.rb

# Returns the public URL of the attachment with a given style. This does
# not necessarily need to point to a file that your Web server can access
# and can instead point to an action in your app, for example for fine grained
# security; this has a serious performance tradeoff.
#
# Options:
#
# +timestamp+ - Add a timestamp to the end of the URL. Default: true.
# +escape+    - Perform URI escaping to the URL. Default: true.
#
# Global controls (set on has_attached_file):
#
# +interpolator+  - The object that fills in a URL pattern's variables.
# +default_url+   - The image to show when the attachment has no image.
# +url+           - The URL for a saved image.
# +url_generator+ - The object that generates a URL. Default: Paperclip::UrlGenerator.
#
# As mentioned just above, the object that generates this URL can be passed
# in, for finer control. This object must respond to two methods:
#
# +#new(Paperclip::Attachment, Paperclip::Options)+
# +#for(style_name, options_hash)+
def url(style_name = default_style, options = {})
  default_options = {:timestamp => @options.use_timestamp, :escape => true}

  if options == true || options == false # Backwards compatibility.
    @url_generator.for(style_name, default_options.merge(:timestamp => options))
  else
    @url_generator.for(style_name, default_options.merge(options))
  end
end

默认情况下回形针附加一个时间戳参数，将:timestamp => false传递给附件的url方法：

image = Magick::ImageList.new('public' + @picture.photo.url(:original, :timestamp => false))

# => "public/system/photos/115/original/Kitchener-2011103100531.jpg"

编辑：实际上，看起来他们更改了选项名称，因为这不适用于 Paperclip 2.4.0。检查我自己的源代码后，选项是 :use_timestamp，但在 github 上是 :timestamp - 根据您使用的回形针版本选择哪一个。

【讨论】：