Txmt protocol for emacs

FirefoxEmacsHandler

#!/usr/bin/env ruby

# To install:
# about:config
# create a new boolean network.protocol-handler.external.txmt with value true
# create a new string network.protocol-handler.app.txmt with value path to the script

require 'rubygems'
require 'cgi'
require 'uri'
require 'logger'

class UrlParser
  attr_reader :url, :file, :line, :column
  def initialize(url)
    @url = CGI::unescape(url.gsub(/(emacs|txmt):\/\/open\?url=/, ''))
    parse_url
  end

  def to_args
    [line_and_column, file].compact.join(' ')
  end

  def line_and_column
    if line
      "+" << [line, column].compact.join(':')
    end
  end

  private

  # url = 'txmt://open?url=file:///url/to/file.txt&line=3&column=8'
  # url = 'emacs://open?url=file:///url/to/file.txt&line=1&column=3'
  def parse_url
    regexp = Regexp.new(/file:\/\/([^&]+)(?:&line=([0-9]+))?(?:&column=([0-9]+))?/)
    if url.match(regexp)
      @file = $1
      @line = $2
      @column = $3
    else
      @file = url
    end
  end
end

class EmacsClient
  DEFAULT_COMMAND = "/usr/bin/emacsclient -a /usr/bin/emacs"

  attr_reader :command, :arguments

  def initialize(args, command=nil)
    @command = command || DEFAULT_COMMAND
    @arguments = args
  end

  def launch
    exec "#{command} #{arguments}"
  end
end

parser = UrlParser.new(ARGV[0])
emacs = EmacsClient.new(parser.to_args)
emacs.launch