如何在异步调用，自定义指令中设置AngularJS模型值？

Question

我想在模型中更改输入元素和赋值的值，在异步验证器指令中。

angular
    .module('lion.Form_Validator')
    .directive('phoneValidation', Lion_Form_Validator_Phone)

function Lion_Form_Validator_Phone($q, $http) {
    return {
        restrict: 'A',
        require: 'ngModel',
        link: function (scope, element, attrib, ngModel) {
            ngModel.$asyncValidators.phone = function (modelValue, viewValue) {
                if (ngModel.$isEmpty(modelValue))
                    return $q.when();

                $http.get('/?check-phone-numbers=' + modelValue, {cache: true}).then(function (res) {
                    if (!res.data.valid) {
                        deferred.reject();
                    } else {
                        /*********************/
                        // here want change the value of input and model
                        //element.val(res.data.phone); -> this not update the model

                        deferred.resolve();
                    }
                });
                return deferred.promise;
            };
        }
    };
}

示例HTML代码：

<div data-ng-controller="BalanceController as balance">
    <input type="text" name="phone" id="phone" data-phone-validation="" data-ng-model="balance.form.phone">
</div>