自定义表单验证指令

'use strict';

/*
 *检测用户名是否存在
 */
angular.module('nswApp')
  .directive('checkname', function() {
    return {
      require: 'ngModel',
      restrict: 'A',
      scope: {
        checkName: '&checkName'
      }
      link: function(scope, elem, attrs, ctrl) {
        elem.on('blur', function() {
          var result = scope.checkName()
            .then(function(response) {
              if (response.value) {
                ctrl.$setValidity('checkname', false);
              } else {
                ctrl.$setValidity('checkname', true);
              }
            }, function(error) {

            });
        });
      }
    };
  });