Module: StickyFlag::Tags::PDF

Defined in:
lib/stickyflag/tags/pdf.rb

Class Method Summary collapse

Class Method Details

.clear(file_name, pdftk_path = 'pdftk') ⇒ Object 



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# File 'lib/stickyflag/tags/pdf.rb', line 95

def clear(file_name, pdftk_path = 'pdftk')
  write_tags_to(file_name, [], pdftk_path)
end

.config_values ⇒ Object 



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# File 'lib/stickyflag/tags/pdf.rb', line 14

def config_values
  [ :pdftk_path ]
end

.extensions ⇒ Object 



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# File 'lib/stickyflag/tags/pdf.rb', line 11

def extensions
  [ '.pdf' ]
end

.get(file_name, pdftk_path = 'pdftk') ⇒ Object 



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# File 'lib/stickyflag/tags/pdf.rb', line 18

def get(file_name, pdftk_path = 'pdftk')
  stdout_str = ''
  stderr_str = ''

  begin
    Open3.popen3(pdftk_path, file_name.to_s, 'dump_data_utf8') do |i, o, e, t|
      out_reader = Thread.new { o.read }
      err_reader = Thread.new { e.read }
      i.close
      stdout_str = out_reader.value
      stderr_str = err_reader.value

      stdout_str.force_encoding("UTF-8") if RUBY_VERSION >= "1.9.0"
      stderr_str.force_encoding("UTF-8") if RUBY_VERSION >= "1.9.0"
    end
  rescue Exception
    raise Thor::Error.new("ERROR: Failed to get tags for #{file_name}; pdftk call failed")
  end
  if stderr_str.start_with?("Error: ") || stderr_str.include?("Errno::ENOENT")
    raise Thor::Error.new("ERROR: Failed to get tags for #{file_name}; pdftk call failed")
  end

  # More than one of these shouldn't be possible, but try to recover if
  # it somehow happens.
  matches = stdout_str.scan(/InfoKey: X-StickyFlag-Flags\nInfoValue: (.*?)\n/)
  return [] if matches.empty?

  tags = []

  matches.each do |m|
    match_string = m[0]
    match_tags = match_string.split(',').map { |t| t.empty? ? nil : t.strip }.compact
    next if match_tags.empty?
  
    tags.concat(match_tags)
  end

  tags
end

.set(file_name, tag, pdftk_path = 'pdftk') ⇒ Object 



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# File 'lib/stickyflag/tags/pdf.rb', line 77

def set(file_name, tag, pdftk_path = 'pdftk')
  tags = get(file_name, pdftk_path)
  return if tags.include? tag

  tags << tag
  
  write_tags_to(file_name, tags, pdftk_path)
end

.unset(file_name, tag, pdftk_path = 'pdftk') ⇒ Object 



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# File 'lib/stickyflag/tags/pdf.rb', line 86

def unset(file_name, tag, pdftk_path = 'pdftk')
  tags = get(file_name, pdftk_path)
  return unless tags.include? tag

  tags.delete(tag)
  
  write_tags_to(file_name, tags, pdftk_path)
end

.write_tags_to(file_name, tags, pdftk_path = 'pdftk') ⇒ Object 



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# File 'lib/stickyflag/tags/pdf.rb', line 58

def write_tags_to(file_name, tags, pdftk_path = 'pdftk')
  info = Tempfile.new_with_encoding ['sfpdftag', '.txt']
  begin
    info.write("InfoKey: X-StickyFlag-Flags\n")
    info.write("InfoValue: #{tags.join(', ')}\n")
    info.close
  
    outpath = File.tmpnam('.pdf')
    ret = system(pdftk_path, file_name, 'update_info', info.path, 'output', outpath)
    unless ret == true
      raise Thor::Error.new("ERROR: Failed to write tag for #{file_name}; pdftk call failed")
    end
    
    FileUtils.mv outpath, file_name
  ensure
    info.unlink
  end
end