isDefined

thirdparties.js

  // isDefined(window, 'google');
  // isDefined(window, 'google.maps.places'); 
  var isDefined = function(parent, name) {
      var parts   = name.split('.');
      var part    = parts.shift();
      var cur     = parent;

      while (part) {
        if (cur[part]) {
            cur = cur[part];
            part = parts.shift();
        } else {
            cur = null;
            part = null;
        }
      }
      return cur !== null;
   };