Module: MppReader::RtfText

Defined in:
lib/mpp_reader/rtf_text.rb

Overview

Minimal RTF-to-plain-text conversion for notes fields. MS Project stores notes as simple RTF (font/color tables, par breaks, hex and unicode escapes); anything not starting with {rtf is returned as-is.

Constant Summary collapse

SKIP_GROUPS =

Destination groups whose text is not document content.

%w[fonttbl colortbl stylesheet info pict object header
footer generator].freeze

Class Method Summary collapse

Class Method Details

.strip(text) ⇒ Object 



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# File 'lib/mpp_reader/rtf_text.rb', line 12

def strip(text)
  return text if text.nil? || text.empty? || !text.start_with?("{\\rtf")

  out = +""
  pos = 0
  bytes = text.b
  # Each entry mirrors the group nesting: true while inside a skipped
  # destination group.
  skip_stack = [false]
  pending_unicode_skip = 0

  while pos < bytes.bytesize
    ch = bytes[pos]
    case ch
    when "{"
      skip_stack.push(skip_stack.last)
      pos += 1
    when "}"
      skip_stack.pop if skip_stack.size > 1
      pos += 1
    when "\\"
      pos = control(bytes, pos, out, skip_stack) { pending_unicode_skip = _1 }
    else
      if pending_unicode_skip.positive?
        pending_unicode_skip -= 1
      elsif !skip_stack.last && ch != "\r" && ch != "\n"
        out << ch
      end
      pos += 1
    end
  end
  out.sub!(/\n\z/, "") # formal RTF always ends with one extra \par
  out.force_encoding(Encoding::UTF_8).valid_encoding? ? out.force_encoding(Encoding::UTF_8) : out
end