使用Rails应用程序中的ActionMailer，winmail.dat附件损坏

1 回答

• 1

  anexo.body.decoded方法调用附件的最适合编码（ Mail::Encodings ）的解码方法，在您的情况下为quoted_printable .

  其中一些编码（7bit，8bit和quoted_printable）执行转换，将不同类型的换行符更改为特定于平台的换行符 . * quoted_printable“调用.to_lf来破坏winmail.dat文件

  # Decode the string from Quoted-Printable. Cope with hard line breaks
    # that were incorrectly encoded as hex instead of literal CRLF.
    def self.decode(str)
      str.gsub(/(?:=0D=0A|=0D|=0A)\r\n/, "\r\n").unpack("M*").first.to_lf
    end
  

  邮件/ core_extensions / string.rb：

  def to_lf
    to_str.gsub(/\n|\r\n|\r/) { "\n" }
  end
  

  要解决这个问题，您可以在没有最后一个.to_lf的情况下执行相同的编码 . 为此，您可以创建一个新的编码，该编码不会损坏您的文件并使用它来编码您的附件 .

  创建文件：lib / encodings / tnef_encoding.rb

  require 'mail/encodings/7bit'
  
  module Mail
    module Encodings
  
      # Encoding to handle Microsoft TNEF format
      # It's pretty similar to quoted_printable, except for the 'to_lf' (decode) and 'to_crlf' (encode)
      class TnefEncoding < SevenBit
        NAME='tnef'
  
        PRIORITY = 2
  
        def self.can_encode?(str)
          EightBit.can_encode? str
        end
  
        def self.decode(str)
          # **difference here** removed '.to_lf'
          str.gsub(/(?:=0D=0A|=0D|=0A)\r\n/, "\r\n").unpack("M*").first
        end
  
        def self.encode(str)
          # **difference here** removed '.to_crlf'
          [str.to_lf].pack("M")
        end
  
        def self.cost(str)
          # These bytes probably do not need encoding
          c = str.count("\x9\xA\xD\x20-\x3C\x3E-\x7E")
          # Everything else turns into =XX where XX is a
          # two digit hex number (taking 3 bytes)
          total = (str.bytesize - c)*3 + c
          total.to_f/str.bytesize
        end
  
        private
  
        Encodings.register(NAME, self)
      end
    end
  end
  

  要使用自定义编码，首先必须注册它：

  Mail::Encodings.register('tnef', Mail::Encodings::TnefEncoding)
  

  然后，将其设置为附件的首选编码：

  anexo.body.encoding('tnef')
  

  那么你的测试将成为：

  it 'should extract winmail.dat from email and extract its contents' do
      file_path = "#{::Rails.root}/spec/files/winmail-dat-001.eml"
      message = Mail::Message.new(File.read(file_path))
      anexo = message.attachments[0]
  
      tmpfile_name = "#{::Rails.root}/tmp/#{anexo.filename}"
      Mail::Encodings.register('tnef', Mail::Encodings::TnefEncoding)
      anexo.body.encoding('tnef')
      File.open(tmpfile_name, 'w+b', 0644) { |f| f.write anexo.body.decoded }
      anexo = File.open(tmpfile_name)
  
      files = []
      Tnef.unpack(anexo) do |file|
          files << File.basename(file)
      end
      puts files.inspect
      files.size.should == 2
  end
  

  希望能帮助到你！

  回复于 2024-05-10T21:31:39+08:00