require 'win32ole-ext'

module Msxml

  def Msxml.new
    return WIN32OLE.new_with_const('MSXML.DOMDocument', Msxml)
  end

  class ParseError < StandardError
  end
  
  def Msxml.handle_error(doc, url)
    error = doc.parseError
    if error.errorCode != 0 then
      docpos = ""
      if error.line != 0 then
        docpos = sprintf(":%d:%d", error.line, error.linepos)
      end
      msg = sprintf("\n%s%s: %s",
                    url, docpos, error.reason.gsub(/\r/, ""))
      raise ParseError, msg
    end
  end

  def Msxml.open(url, preserveWhiteSpace = false, async = false)
    doc = new
    doc.preserveWhiteSpace = preserveWhiteSpace
    doc.async = async
    doc.load(url) 
    begin
      handle_error(doc, url)
    rescue ParseError
      raise $!.type, $!.message, caller
    end
    return doc
  end

end