Question

我是RoR的新手，我正在尝试开发一个幻灯片共享应用，用户可以通过该应用上传和共享包含幻灯片（每页一张幻灯片）的多页PDF。然后，观看者可以在“显示”页面上查看这些幻灯片。

在幕后我试图将多页pdf转换成几个.png文件（1 pdf页面 - ＆gt; 1.png文件），然后以轮播/滑块方式显示它们。

这是我的上传者：

# encoding: utf-8

class DocUploader < CarrierWave::Uploader::Base

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

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

# Override the directory where uploaded files will be stored.
# This is a sensible default for uploaders that are meant to be mounted:
  def store_dir
  #  'public/doc_uploads/'
    "uploads/#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}"
  end

  process :filename
  process :generate_png

  def generate_png
    pdf = MiniMagick::Image.new(self.file.path)
    pdf.pages.each_with_index do |page, index|
      page.write("page#{index}.png")
    end
  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(pdf)
    end

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

end

当我尝试上传多页pdf文档时，它会抛出此错误：行'identify /public/uploads/tmp/1443619784-406-3861/doc.pdf' failed with error:

pdf.pages.each_with_index do |page, index|

我尝试了不同的解决方案来转换文档，但到目前为止，它们都没有对我有用。为什么磨机.pdf文件的运行会失败minimagick的验证？有什么办法可以避免遇到这个问题吗？任何建议将不胜感激！

Minimagick gem无法将多页PDF转换为多个png图像

0 个答案: