ASP.NET Core AutoWrapper 自定義響應輸出

前言 AutoWrapper是一個簡單可自定義全局異常處理程式和ASP.NET Core API響應的包裝。他使用ASP.NET Core middleware攔截傳入的HTTP請求，並將最後的結果使用統一的格式來自動包裝起來.目的主要是讓我們更多的關註業務特定的代碼要求，並讓包裝器自動處理HTTP ...

前言

AutoWrapper是一個簡單可自定義全局異常處理程式和ASP.NET Core API響應的包裝。他使用ASP.NET Core middleware攔截傳入的HTTP請求，並將最後的結果使用統一的格式來自動包裝起來.目的主要是讓我們更多的關註業務特定的代碼要求，並讓包裝器自動處理HTTP響應。這可以在構建API時加快開發時間，同時為HTTP響應試試我們統一的標準。

安裝

AutoWrapper.Core從NuGet或通過CLI下載並安裝

PM> Install-Package AutoWrapper.Core

在Startup.cs Configure方法中註冊以下內容，但是切記要放在UseRouting前

app.UseApiResponseAndExceptionWrapper();

啟動屬性映射

預設情況下AutoWrapper將在成功請求成功時輸出以下格式：

{
    "message": "Request successful.",
    "isError": false,
    "result": [
      {
        "id": 7002,
        "firstName": "Vianne",
        "lastName": "Durano",
        "dateOfBirth": "2018-11-01T00:00:00"
      }
    ]
}

如果說不喜歡預設屬性命名方式，那麼我們可以通過AutoWrapperPropertyMap屬性進行映射為我們需要指定的任何名稱。例如我麽可以將result屬性的名稱更改為data。如下所示

public class MapResponseObject  
{
    [AutoWrapperPropertyMap(Prop.Result)]
    public object Data { get; set; }
}

然後將MapResponseObject類傳遞給AutpWrapper middleware

app.UseApiResponseAndExceptionWrapper<MapResponseObject>();

通過映射重新請求後，現在影響格式如下所示

{
    "message": "Request successful.",
    "isError": false,
    "data": {
        "id": 7002,
        "firstName": "Vianne",
        "lastName": "Durano",
        "dateOfBirth": "2018-11-01T00:00:00"
    }
}

可以從中看出result屬性已經更換為data屬性了

預設情況下AutoWrapper發生異常時將吐出以下響應格式

{
    "isError": true,
    "responseException": {
        "exceptionMessage": "Unhandled Exception occurred. Unable to process the request."
    }
}

而且如果在AutoWrapperOptions中設置了IsDebug，則將產生帶有堆棧跟蹤信息的類似信息

{
    "isError": true,
    "responseException": {
        "exceptionMessage": " Input string was not in a correct format.",
        "details": "   at System.Number.ThrowOverflowOrFormatException(ParsingStatus status, TypeCode type)\r\n   at System.Number.ParseInt32(ReadOnlySpan`1 value, NumberStyles styles, NumberFormatInfo info)\r\n …"
    }
}

如果想將某些APIError屬性名稱更改為其他名稱，只需要在以下代碼中添加以下映射MapResponseObject

public class MapResponseObject  
{
    [AutoWrapperPropertyMap(Prop.ResponseException)]
    public object Error { get; set; }

    [AutoWrapperPropertyMap(Prop.ResponseException_ExceptionMessage)]
    public string Message { get; set; }

    [AutoWrapperPropertyMap(Prop.ResponseException_Details)]
    public string StackTrace { get; set; }
}

通過如下代碼來模擬錯誤

int num = Convert.ToInt32("10s");

現在映射後的輸出如下所示

{
    "isError": true,
    "error": {
        "message": " Input string was not in a correct format.",
        "stackTrace": "   at System.Number.ThrowOverflowOrFormatException(ParsingStatus status, TypeCode type)\r\n   at System.Number.ParseInt32(ReadOnlySpan`1 value, NumberStyles styles, NumberFormatInfo info)\r\n …"
    }
}

請註意APIError現在根據MapResponseObject類中定義的屬性更改了模型的預設屬性。

我們可以自由的選擇映射任何屬性，下麵是映射屬性相對應的列表

[AutoWrapperPropertyMap(Prop.Version)]
[AutoWrapperPropertyMap(Prop.StatusCode)]
[AutoWrapperPropertyMap(Prop.Message)]
[AutoWrapperPropertyMap(Prop.IsError)]
[AutoWrapperPropertyMap(Prop.Result)]
[AutoWrapperPropertyMap(Prop.ResponseException)]
[AutoWrapperPropertyMap(Prop.ResponseException_ExceptionMessage)]
[AutoWrapperPropertyMap(Prop.ResponseException_Details)]
[AutoWrapperPropertyMap(Prop.ResponseException_ReferenceErrorCode)]
[AutoWrapperPropertyMap(Prop.ResponseException_ReferenceDocumentLink)]
[AutoWrapperPropertyMap(Prop.ResponseException_ValidationErrors)]
[AutoWrapperPropertyMap(Prop.ResponseException_ValidationErrors_Field)]
[AutoWrapperPropertyMap(Prop.ResponseException_ValidationErrors_Message)]

自定義錯誤架構

AutoWrapper還提供了一個APIException可用於定義自己的異常的對象，如果想拋出自己的異常消息，則可以簡單地執行以下操作

throw new ApiException("Error blah", 400, "511", "http://blah.com/error/511");

預設輸出格式如下所示

{
    "isError": true,
    "responseException": {
        "exceptionMessage": "Error blah",
        "referenceErrorCode": "511",
        "referenceDocumentLink": "http://blah.com/error/511"
    }
}

當然我們可以自定義錯誤格式

public class MapResponseObject  
{
    [AutoWrapperPropertyMap(Prop.ResponseException)]
    public object Error { get; set; }
}

public class Error  
{
    public string Message { get; set; }

    public string Code { get; set; }
    public InnerError InnerError { get; set; }

    public Error(string message, string code, InnerError inner)
    {
        this.Message = message;
        this.Code = code;
        this.InnerError = inner;
    }

}

public class InnerError  
{
    public string RequestId { get; set; }
    public string Date { get; set; }

    public InnerError(string reqId, string reqDate)
    {
        this.RequestId = reqId;
        this.Date = reqDate;
    }
}

然後我們可以通過如下代碼進行引發我們錯誤

throw new ApiException(  
      new Error("An error blah.", "InvalidRange",
      new InnerError("12345678", DateTime.Now.ToShortDateString())
));

輸出格式如下所示

{
    "isError": true,
    "error": {
        "message": "An error blah.",
        "code": "InvalidRange",
        "innerError": {
            "requestId": "12345678",
            "date": "10/16/2019"
        }
    }
}

使用自定義API響應格式

如果映射滿足不了我們的需求。並且我們需要向API響應模型中添加其他屬性，那麼我們現在可以自定義自己的格式類，通過設置UseCustomSchema為true來實現，代碼如下所示

app.UseApiResponseAndExceptionWrapper(new AutoWrapperOptions { UseCustomSchema = true });

現在假設我們想在主API中響應中包含一個屬性SentDate和Pagination對象，我們可能希望將API響應模型定義為以下格式

public class MyCustomApiResponse  
{
    public int Code { get; set; }
    public string Message { get; set; }
    public object Payload { get; set; }
    public DateTime SentDate { get; set; }
    public Pagination Pagination { get; set; }

    public MyCustomApiResponse(DateTime sentDate, object payload = null, string message = "", int statusCode = 200, Pagination pagination = null)
    {
        this.Code = statusCode;
        this.Message = message == string.Empty ? "Success" : message;
        this.Payload = payload;
        this.SentDate = sentDate;
        this.Pagination = pagination;
    }

    public MyCustomApiResponse(DateTime sentDate, object payload = null, Pagination pagination = null)
    {
        this.Code = 200;
        this.Message = "Success";
        this.Payload = payload;
        this.SentDate = sentDate;
        this.Pagination = pagination;
    }

    public MyCustomApiResponse(object payload)
    {
        this.Code = 200;
        this.Payload = payload;
    }

}

public class Pagination  
{
    public int TotalItemsCount { get; set; }
    public int PageSize { get; set; }
    public int CurrentPage { get; set; }
    public int TotalPages { get; set; }
}

通過如下代碼片段進行測試結果

public async Task<MyCustomApiResponse> Get()  
{
    var data = await _personManager.GetAllAsync();

    return new MyCustomApiResponse(DateTime.UtcNow, data,
        new Pagination
        {
            CurrentPage = 1,
            PageSize = 10,
            TotalItemsCount = 200,
            TotalPages = 20
        });

}

運行後會得到如下影響格式


{
    "code": 200,
    "message": "Success",
    "payload": [
        {
            "id": 1,
            "firstName": "Vianne",
            "lastName": "Durano",
            "dateOfBirth": "2018-11-01T00:00:00"
        },
        {
            "id": 2,
            "firstName": "Vynn",
            "lastName": "Durano",
            "dateOfBirth": "2018-11-01T00:00:00"
        },
        {
            "id": 3,
            "firstName": "Mitch",
            "lastName": "Durano",
            "dateOfBirth": "2018-11-01T00:00:00"
        }
    ],
    "sentDate": "2019-10-17T02:26:32.5242353Z",
    "pagination": {
        "totalItemsCount": 200,
        "pageSize": 10,
        "currentPage": 1,
        "totalPages": 20
    }
}

但是從這裡要註意一旦我們對API響應進行自定義，那麼就代表我們完全控制了要格式化數據的方式，同時丟失了預設API響應的某些選項配置。但是我們仍然可以利用ApiException()方法引發用戶定義的錯誤消息
如下所示

[Route("{id:long}")]
[HttpPut]
public async Task<MyCustomApiResponse> Put(long id, [FromBody] PersonDTO dto)  
{
    if (ModelState.IsValid)
    {
        try
        {
            var person = _mapper.Map<Person>(dto);
            person.ID = id;

            if (await _personManager.UpdateAsync(person))
                return new MyCustomApiResponse(DateTime.UtcNow, true, "Update successful.");
            else
                throw new ApiException($"Record with id: {id} does not exist.", 400);
        }
        catch (Exception ex)
        {
            _logger.Log(LogLevel.Error, ex, "Error when trying to update with ID:{@ID}", id);
            throw;
        }
    }
    else
        throw new ApiException(ModelState.AllErrors());
}

現在當進行模型驗證時，可以獲得預設響應格式

{
    "isError": true,
    "responseException": {
        "exceptionMessage": "Request responded with validation error(s). Please correct the specified validation errors and try again.",
        "validationErrors": [
            {
                "field": "FirstName",
                "message": "'First Name' must not be empty."
            }
        ]
    }
}

Reference

https://github.com/proudmonkey/AutoWrapper