simple autogrow directive for textareas in angularjs

autogrow.directive.js

// Usage: <textarea auto-grow></textarea>
appModule.directive('autoGrow', function() {
  return function(scope, element, attr){
      var update = function(){
          element.css("height", "auto");
          element.css("height", element[0].scrollHeight + "px");
      };
      scope.$watch(attr.ngModel, function(){
          update();
      });
      attr.$set("ngTrim", "false");
  };
});