Custom javascript logger

custom_logger.js

(function (undefined) {
  // handles all the console methods to make the console persistent, mainly for IE
  if (window.console === undefined) {
    window.console = {};
  }
  (function () {
    var methods = ["log", "debug", "info", "warn", "error", "assert", "dir", "dirxml", "group", "groupEnd", "time", "timeEnd", "count", "trace", "profile", "profileEnd"],
      i = methods.length;
    for ( ; i--; ) {
      if ( !window.console[ methods[i] ] ) {
        window.console[ methods[i] ] = function () {};
      }
    }
  }());
}());

(function(window) {

  var qs = {};
  function logger() {
    var s = window.location.search.substring(1),
      ss = s.split('&'),
      i = ss.length;
    while (i--) {
      var si = ss[i],
        sp = si.split('=') ,
        l = sp[0],
        r = sp[1];
      qs[l] = r;
    }
  }

  logger();
  var log = function () {
    if (qs.debug === 'true') {
      var args = Array.prototype.slice.call(arguments),
        arg0 = args[0],
        is_method = !!window.console[arg0],
        method = is_method ? window.console[arg0] : window.console.log,
        args_to_apply = is_method ? args.slice(1) : args;
      console.log(args);
      method.apply(window.console, args_to_apply)
    }
  };

  // to expose this logger to the global namespace:
  // window.log = log;

}(window));