Toggle default value on focus and blur on text field

default.value.directive.js

/**
 * @ngdoc Directive
 * @name defaultValue
 * @restrict 'A'
 * @element ANY 
 * @author Mohan Singh ( gmail::mslogicmaster@gmail.com, skype :: mohan.singh42 )
 **/
(function () {
  'use strict';
  angular
    .module('tallyfy')
    .directive('defaultValue', ['_', function (_) { // '_' is a dependency for lodash
      return {
        restrict: 'A',
        require: '^ngModel',
        link: function (scope, element, attrs, modelCtrl) {
          var currValue;

          element.bind('focus', function (event) {
            if (_.isEmpty(currValue)) {
              currValue = modelCtrl.$modelValue;
            }
            if (currValue === modelCtrl.$modelValue) {
              modelCtrl.$setViewValue('');
               modelCtrl.$render();
            }
          });

          element.bind('blur', function (event) {
            if (_.isEmpty(modelCtrl.$modelValue)) {
              modelCtrl.$setViewValue(currValue);
              modelCtrl.$render();
            }
          });

          scope.$on('$destroy', function () {
            element.unbind('focus blur');
          })
        }
      }
    }]);

})();