如何将错误呈现给客户端？AngularJS/WebAPI模型状态

Question

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     {"Message":"The request is invalid.","ModelState":{"model.LastName":["Last Name must be at least 2 characters long."]}}

然后如何用AngularJS将其呈现给客户机？

      //Save User Info
    $scope.processDriverForm = function(isValid) {
        if (isValid) {
            //set button disabled, icon, text
            $scope.locked = true;
            $scope.icon = 'fa fa-spinner fa-spin';
            $scope.buttonText = 'Saving...';
            $scope.submitted = true;
            $scope.formData.birthDate = $scope.formData.birthMonth + '/' + $scope.formData.birthDay + '/' + $scope.formData.birthYear;
            $http({
                    method: 'POST',
                    url: 'api/Account/Register',
                    data: $.param($scope.formData),
                    headers: { 'Content-Type': 'application/x-www-form-urlencoded' } // set the headers so angular passing info as form data (not request payload)
                })
                .success(function (data) {
                    console.log(data);
                    toastr.success('User ' + $scope.formData.username + ' created!');
                    $scope.userForm.$setPristine();
                    $scope.formData = {};
                    //reset the button
                    $scope.locked = false;
                    $scope.icon = '';
                    $scope.buttonText = 'Save';
                    //reset validation submitted
                    $scope.submitted = false;
                })
                .error(function (data, response) {
                    console.log(data);
                    toastr.error('Ooops! There was an error creating the user. Try again and if the problem persists, contact Support.');
                    //reset the button
                    $scope.locked = false;
                    $scope.icon = '';
                    $scope.buttonText = 'Save';
                    $scope.submitted = false;

                    var resp = {};

                    var errors = [];
                    for (var key in resp.ModelState) {
                        for (var i = 0; i < resp.ModelState[key].length; i++) {
                            errors.push(resp.ModelState[key][i]);
                        }
                    }
                    $scope.errors = errors;

                });

        }
        else {
            toastr.warning('Invalid User Form, correct errors and try again.');
        }
    };

Answer 1

最简单的方法可能是从ModelState中获取所有错误，并将它们放入Scope上的一个新属性中。

$http.post(url, data).
    success(successHandler).
    error(function (response) {
        $scope.errors = getErrors(response);
    });

function getErrors(responseWithModelState) {
    var errors = [];
    /*
    Get error messages out of ModelState property, and push them into the errors variable...
    Brocco beat me to it. :-)
    */
    return errors;
};

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<ul>
    <li ng-repeat="e in errors">{{e}}</li>
</ul>

或者，不是在每个错误处理程序中都这样做，您可以编写一次它，然后通过使用拦截器将它应用于每个HTTP请求。我自己从来没有写过，所以我将把你指向doc（向下滚动到拦截器部分）。

Answer 2

在调用服务器时，捕获基于拒绝 承诺的错误。

那么在您的控制器中，我建议在处理错误时将对错误数组的响应扁平化，以便显示，如以下fiddle示例所示:

for (var key in resp.ModelState) {
    for (var i = 0; i < resp.ModelState[key].length; i++) {
        errors.push(resp.ModelState[key][i]);
    }
}

总而言之:

// Post the data to the web api/service
$http.post(url, data)
    .success(successHandler)
    .error(function (response) {
        // when there's an error, parse the error
        // and set it to the scope (for binding)
        $scope.errors = parseErrors(response);
    });

//separate method for parsing errors into a single flat array
function parseErrors(response) {
    var errors = [];
    for (var key in response.ModelState) {
        for (var i = 0; i < response.ModelState[key].length; i++) {
            errors.push(response.ModelState[key][i]);
        }
    }
    return errors;
}