Convert FreeMind's *.mm file into text

mm2txt.rb

require 'rexml/document'

class Mm2Txt

  def self.convert(filename, out=STDOUT)
    contents = File.open(filename, 'r', &:read)
    doc = REXML::Document.new(contents)
    Impl.traverse(0, doc.elements['//map/node'], out)
  end

  class Impl

    def self.is_node_element(elem)
      elem.class == REXML::Element && elem.name == 'node'
    end

    def self.traverse(depth, node, out)
      out.write(" " * (depth * 4))
      out.write("#{node.attributes['TEXT'].to_s}\n")
      node.elements.select{ |e| is_node_element(e) }.each do |e|
        traverse(depth + 1, e, out)
      end
    end
  end
end


if $0 == __FILE__
  def usage
    puts "ruby mm2txt.rb target_mm_file_name"
    exit
  end

  usage() if ARGV.empty? 
  Mm2Txt.convert(ARGV[0])
end