balsamiq_export.rb

#!/usr/bin/env ruby

# This script will automatically export all the Balsamiq mock files to PDF and bundle them up
# into a nice PDF.  Just drop this script into the folder containing the mock files and 
# execute it from the command-line
# 
# For the PDF to work, you'd need to install "prawn" and "prawn-fast-png" gem, otherwise the PDF
# creation will be very slow.
# 
# Currently this script has been tested with Balsamiq Next.161 build (05/28/2010)
# and Ruby 1.8.7 running on Snow Leopard
#

require 'rubygems'
require 'prawn'
require "prawn/measurement_extensions"
require 'prawn/fast_png'
require 'ruby-debug'
 
balsamiq = "/Volumes/Macintosh HD/Applications/Balsamiq Mockups.app/Contents/MacOS/Balsamiq Mockups"

output_dir      = "./output"                      # output folder for images 
output_format   = "png"                           # The format that Balsamiq would export.  Currently png only
remove_old_images_from_output_dir = true         # Remove images in the Output folder and not in Input folder

ignored_files = [                                 # Any files in this array will be skipped.  File name is case-sensitive
  "blank.bmml",
  "ANOTHER_FILE.bmml"
]



export_to_pdf = true                              # Export to output_dir/mock.pdf
output_pdf    = "#{output_dir}/mock.pdf"          # Where the PDF file should be exported to
paper_size    = 'A4'                              # how big the page should be



# Setting up output dir to not clutter up the current folder
Dir.mkdir( output_dir ) unless ( File.exists?( output_dir ) or File.directory?( output_dir ) )

class Util
  def self.store obj, file_name
    marshal_dump = Marshal.dump(obj)
    file = File.new(file_name,'w')
    file.write marshal_dump
    file.close
    return obj
  end
  
  def self.load file_name
    return nil unless File.exists? file_name
    file = File.open(file_name, 'r')
    obj = Marshal.load file.read
    file.close
    return obj
  end
  
  def self.dimension_of png_file
    IO.read( png_file )[0x10..0x18].unpack('LL')
  end
end

# Time a running block.
def time( msg )
  start = Time.now
  puts "Begin #{msg}"
  yield
  puts "Finish #{msg} .  Time elapsed: #{Time.now - start} seconds" 
end


# File to save last run info about the files
checkpoint_file = "#{output_dir}/checkpoint"

# remove files in Output but not in input
if remove_old_images_from_output_dir
  images = Dir.glob "#{output_dir}/*.#{output_format}"
  files  = Dir.glob "*.bmml" || {}
  images.each do |image| 
   if files.collect{ |file| file if image.index(file) and image.index(file) > 0 }.compact.empty?
      puts "[DELETE] #{output_dir}/#{image} (old files)"
      File.delete "#{image}"
    end
  end
end

puts "==========="

# read in checkpoint file so that we can skip already generated files that are unchanged
last_run = Util.load checkpoint_file
last_run ||= {}

images = []
next_run = {}
files.each do |file|
  next if ignored_files.index( file )
  
  if last_run[ file ] != File.mtime( file ) 
    puts "[ADD] #{file} (to be exported to #{output_format})"
    next_run[ file ] = File.mtime( file )
  else 
    puts "[REUSE] #{file} (same as last time)"
  end

  # Enqueue the image to be generated and included in the PDF
  images << "#{output_dir}/#{file}.#{output_format}"
end


# now export 
time "Exporting Mocks" do
  next_run.each do |file, mtime|
    puts "[EXPORT] #{file}"
    cmd = %!"#{balsamiq}" export "#{File.expand_path file}" "#{File.expand_path("#{output_dir}/#{file}.#{output_format}") }"!
    #puts cmd
    `#{cmd}`
  end
end



if export_to_pdf 
  # Baill out if there's no images
  return if images.empty?

  # Read the first image size to determine the initial layout

  time "Creating PDF" do
    dim = Util.dimension_of images.first
  
    i = 0
  
    Prawn::Document.generate( "#{output_dir}/mocks.pdf", :page_size => paper_size, :page_layout => dim[1] > dim [ 0 ] ? :portrait : :landscape  ) do 

      # Append image to the pdf document 
      images.each_with_index do |img, i|
        dim = Util.dimension_of( img )
        puts "PDF << #{img} (page #{i+1})"
        start_new_page( :layout => dim[1] > dim [ 0 ] ? :portrait : :landscape ) if i > 0
        image img, :position => :left, :vposition => :top , :fit => bounds.top_right
      end

      # Print the page #
      number_pages "<page>", [bounds.left, 0]
  
      # build the section outline
      define_outline do
        section 'Mock', :page => 1, :closed => true do
          for i in 0...images.length 
            page i + 1, :title => images[i].split('/').last
          end
        end
      end
    end
  end
end

# Saving 
puts "Saving checkpoint file"
Util.store last_run.merge( next_run ), checkpoint_file

puts "DONE"