Run Symfony apps with Rack (rackup! pow!)

config.ru

# vim:se filetype=ruby
# vim:se foldlevel=3
#
# Hacks and monkeys to run Symfony 1.4 applications as Rack apps using
# the rack-legacy and rack-rewrite gems.
#
# A couple of rack-rewrite rules take care of handing requests to the
# default front controller (index.php) and a subclass of rack-legacy's
# Php fixes PATH_INFO for Symfony routing. 
# 
# Got the idea from:
# http://stuff-things.net/2011/05/16/legacy-development-with-pow/

require 'rubygems'
require 'rack'
require 'rack-legacy'
require 'rack-rewrite'

# Your Symfony project web dir 
SF_WEB_DIR = File.join Dir.getwd, 'web'

module Rack
  module Legacy
    class Symfony < Php
      # Strip the script name from PATH_INFO, or Symfony won't be able to parse it 
      def run(env, path)
        if env['PATH_INFO'] =~ %r{^/[^\.]+\.php(.*)$}
          env.merge!({ 'ORIG_PATH_INFO' => env['PATH_INFO'], 'PATH_INFO' => $1 }) 
        end
        super env, path
      end
    end

    # Monkey rack-legacy's error page to detect and use Symfony's error
    # pages by dumping stdout to the browser. 
    class ErrorPage
      # Detect a symfony error page by grepping the version information
      # in the footer
      def symfony_page?
        @stdout =~ %r{<p id="footer">\s+symfony v\.\d+}
      end

      def to_s
        return @stdout if symfony_page?
        ERB.new(template).result binding
      end
    end
  end

end

use Rack::Rewrite do
  # Dispatch any request for "/" to /index.php
  rewrite %r{(^/$)}, lambda {|match, rack_env|
    return '/index.php' if File.exists? File.join(SF_WEB_DIR, 'index.php')
    rack_env['PATH_INFO']
  }

  # Prepend "/index.php" to any URI not matching an existing file 
  # and not containing a php script name 
  rewrite %r{^(?!/[^\.]+\.php)(/.*)$}, lambda { |match, rack_env|
    file = File.join SF_WEB_DIR, rack_env['PATH_INFO']

    unless File.exists? file
      return '/index.php' + rack_env['PATH_INFO'] if File.exists? File.join(SF_WEB_DIR, 'index.php')
    end
    rack_env['PATH_INFO']
  }
end

use Rack::Legacy::Symfony, SF_WEB_DIR
run Rack::File.new SF_WEB_DIR