gistfile1.rb

# PrinceXML Ruby interface. 
# http://www.princexml.com
#
# Library by Subimage Interactive - http://www.subimage.com
#
#
# USAGE
# -----------------------------------------------------------------------------
#   princely = Princely.new()
#   html_string = render_to_string(:template => 'some_document')
#   send_data(
#     princely.pdf_from_string(html_string),
#     :filename => 'some_document.pdf'
#     :type => 'application/pdf'
#   )
#
# http://www.princexml.com/bb/viewtopic.php?t=2927
# Set the path for resovle absolute filenames in the initializer (--fileroot option is added in the prince 7.1)
#   
#   Princely.fileroot = File.join(RAILS_ROOT, 'public')
#

$:.unshift(File.dirname(__FILE__))
require 'logger'

class Princely
  VERSION = "1.0.0" unless const_defined?("VERSION")
  
  attr_accessor :exe_path, :style_sheets, :log_file, :logger
  
  # specify a path that will be used to resolve absolute filenames.
  cattr_accessor :fileroot
  
  # Initialize method
  #
  def initialize()
    # Finds where the application lives, so we can call it.
    @exe_path = `which prince`.chomp
    raise "Cannot find prince command-line app in $PATH" if @exe_path.length == 0
  	@style_sheets = ''
  	@log_file = "#{RAILS_ROOT}/log/prince.log"
  	@logger = RAILS_DEFAULT_LOGGER
  end
  
  # Sets stylesheets...
  # Can pass in multiple paths for css files.
  #
  def add_style_sheets(*sheets)
    for sheet in sheets do
      @style_sheets << " -s #{sheet} "
    end
  end
  
  # Returns fully formed executable path with any command line switches
  # we've set based on our variables.
  #
  def exe_path
    # Add any standard cmd line arguments we need to pass
    @exe_path << " --input=html --server --log=#{@log_file} "
    
    if available_use_fileroot_option? && @@fileroot
      @exe_path << " --fileroot=#{@@fileroot} "
    end
    
    @exe_path << @style_sheets
    return @exe_path
  end
  
  # Makes a pdf from a passed in string.
  #
  # Returns PDF as a stream, so we can use send_data to shoot
  # it down the pipe using Rails.
  #
  def pdf_from_string(string, output_file = '-')
    path = self.exe_path()
    # Don't spew errors to the standard out...and set up to take IO 
    # as input and output
    path << ' --silent - -o -'
    
    # Show the command used...
    logger.info "\n\nPRINCE XML PDF COMMAND"
    logger.info path
    logger.info ''
    
    # Actually call the prince command, and pass the entire data stream back.
    pdf = IO.popen(path, "w+")
    pdf.puts(string)
    pdf.close_write
    result = pdf.gets(nil)
    pdf.close_read
    return result
  end

  def pdf_from_string_to_file(string, output_file)
    path = self.exe_path()
    # Don't spew errors to the standard out...and set up to take IO 
    # as input and output
    path << " --silent - -o '#{output_file}' >> '#{@log_file}' 2>> '#{@log_file}'"
    
    # Show the command used...
    logger.info "\n\nPRINCE XML PDF COMMAND"
    logger.info path
    logger.info ''
    
    # Actually call the prince command, and pass the entire data stream back.
    pdf = IO.popen(path, "w+")
    pdf.puts(string)
    pdf.close
  end
  
  def available_use_fileroot_option?
    `prince --version` =~  /^Prince (\d+\.\d+(\.\d+)?)/
    prince_version = $1
    prince_version =~ /(\d+)\.(\d+)(\.\d+)?/
    major = $1.to_i
    minor = $2.to_i
    major > 7 || (major == 7 && minor >= 1)
  end
  
end