pdf_render.rb

# 
# Action View hook for .rpdf views, to have them filtered via htmldoc and 
# rendered as a PDF file.
# 
# Put it in your lib/ directory, save it with a name of your choice, and require
# it in your environment.rb. Sample controller usage is below.
# 
# Your view must be an HTML 3.2 file, and you can use the additional HTMLDOC comments.
# 
# See <http://www.htmldoc.org/> for more information oh htmldoc, and
# <http://htmldoc.rubyforge.org/> for more information on the htmldoc gem.
# 
# In your controller, do something equivalent (default REST routes assumed):
# 
# class YourController < ApplicationController
#   def some_action
#     format = params[:format] || 'html'
#     render :action => "show.r#{format}", :content_type => Mime.const_get(format.upcase)
#   end
# end
# 
# Untested with Rails versions 2.1 and upwards. Feedback is welcome :).
# 
# - vjt@openssl.it

require 'htmldoc'

class PDF::HTMLDoc::View
  include ApplicationHelper
  include ActionView::Helpers::TagHelper
  include ActionView::Helpers::UrlHelper

  def initialize(action_view)
    @action_view = action_view
    @controller = @action_view.controller
  end

  # Render the PDF
  def render(template, local_assigns = {})
    @controller.headers['Content-Disposition'] ||= 'attachment'
    @controller.instance_variables.each do |v|
      instance_variable_set(v, @controller.instance_variable_get(v))
    end

    markup = ERB.new(template).result(binding)

    PDF::HTMLDoc.create do |pdf|
      { :bodycolor => :white, :toc => false, :portrait => true,
        :links => true, :webpage => true, :left => '2cm', :right => '2cm',
        :path => (Pathname.new(File.join(RAILS_ROOT, 'public')).realpath.to_s)
      }.each do |option, value|  pdf.set_option option, value  end

      pdf << markup
    end
  end
end

ActionView::Base.register_template_handler 'rpdf', PDF::HTMLDoc::View
Mime::Type.register 'application/pdf', :pdf