Watch a Scrivener project for changes and update Marked.app

scrivwatcher.rb

#!/usr/bin/env ruby
# scrivwatch.rb by Brett Terpstra, 2011
# Modifications to merge into one file for Markdown viewing in Marked by BooneJS, 2012
# Modified to use REXML and add titles by Brett Terpstra, 2012 <https://gist.github.com/1676667>
#
# Watch a Scrivener project for changes and update a preview file for Marked
# Usage: scrivwatch.rb /path/to/document.scriv
# <http://markedapp.com>

require 'fileutils'
require 'rexml/document'

def get_children(ele,path,files,depth)
  ele.elements.each('*/BinderItem') do |child|
        id = child.attributes["ID"]
        title = child.elements.to_a[0].text
        file = "#{path}/Files/Docs/#{id}.rtf"
        filepath = File.exists?(file) ? file : false
        files << { 'path' => filepath, 'title' => title, 'depth' => depth }
        get_children(child,path,files,depth+1)
  end
end

# Take the path to the scrivener file and open the internal XML file.
def get_rtf_file_array(scrivpath)
  scrivpath = File.expand_path(scrivpath)
  files = []
  scrivx = File.basename("#{scrivpath}", ".scriv") + ".scrivx"

  doc = REXML::Document.new File.new("#{scrivpath}/#{scrivx}")
  
  drafts = nil
  doc.elements.each('ScrivenerProject/Binder/BinderItem') do |ele|
    if ele.attributes['ID'] == "0"
      get_children(ele,scrivpath,files,1)
    end    
  end

return files
end

trap("SIGINT") { exit }

if ARGV.length != 1 || ARGV[0] !~ /\.scriv\/?$/
  puts "Usage: scrivwatch.rb /path/to/document.scriv"
  exit
end

marked_note = File.expand_path("~/Marked Preview.md")
FileUtils.touch(marked_note)
%x{open -a /Applications/Marked.app "#{marked_note}"}


path = File.expand_path(ARGV[0].gsub(/\/$/,''))
first = true


while true do # repeat infinitely
  notetext = ""
  files = get_rtf_file_array(path)
  new_hash = files.collect {|f| [ f['path'], File.stat(f['path']).mtime.to_i ] if f['path'] } # create a hash of timestamps
  hash ||= new_hash
  diff_hash = new_hash - hash # check for changes
  
  unless first==false and diff_hash.empty? # if changes were found in the timestamps
    first = false
    hash = new_hash
    # All attempts to pass more than 1 file to textutil failed. Do it one-at-a-time.
    files.each{ |f|
      note = f['path'] ? %x{/usr/bin/textutil -convert txt -stdout "#{f['path']}"} : ''
      leader = ""
      f['depth'].times { leader += "#" }
      notetext = notetext + "#{leader} #{f['title']}\n\n" + note + "\n\n"
    }
    # write the result to the preview file
    watch_note = File.new("#{marked_note}",'w') 
    watch_note.puts notetext
    watch_note.close
  end
  
  sleep 1
end