ASP.NET Core AutoWrapper 自定义响应输出

# 前言 AutoWrapper是一个简单可自定义全局异常处理程序和ASP.NET Core API响应的包装。他使用ASP.NET Core middleware拦截传入的HTTP请求，并将最后的结果使用统一的格式来自动包装起来.目的主要是让我们更多的关注业务特定的代码要求，并让包装器自动处理HTTP响应。这可以在构建API时加快开发时间，同时为HTTP响应试试我们统一的标准。 # 安装 AutoWrapper.Core从NuGet或通过CLI下载并安装 ``` PM> Install-Package AutoWrapper.Core ``` 在Startup.cs Configure方法中注册以下内容，但是切记要放在UseRouting前 ``` app.UseApiResponseAndExceptionWrapper(); ``` # 启动属性映射 默认情况下AutoWrapper将在成功请求成功时输出以下格式： ``` { "message": "Request successful.", "isError": false, "result": [ { "id": 7002, "firstName": "Vianne", "lastName": "Durano", "dateOfBirth": "2018-11-01T00:00:00" } ] } ``` 如果说不喜欢默认属性命名方式，那么我们可以通过AutoWrapperPropertyMap属性进行映射为我们需要指定的任何名称。例如我么可以将result属性的名称更改为data。如下所示 ``` public class MapResponseObject { [AutoWrapperPropertyMap(Prop.Result)] public object Data { get; set; } } ``` 然后将MapResponseObject类传递给AutpWrapper middleware ``` app.UseApiResponseAndExceptionWrapper(); ``` 通过映射重新请求后，现在影响格式如下所示 ``` { "message": "Request successful.", "isError": false, "data": { "id": 7002, "firstName": "Vianne", "lastName": "Durano", "dateOfBirth": "2018-11-01T00:00:00" } } ``` 可以从中看出result属性已经更换为data属性了 默认情况下AutoWrapper发生异常时将吐出以下响应格式 ``` { "isError": true, "responseException": { "exceptionMessage": "Unhandled Exception occurred. Unable to process the request." } } ``` 而且如果在AutoWrapperOptions中设置了IsDebug，则将产生带有堆栈跟踪信息的类似信息 ``` { "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 …" } } ``` 如果想将某些APIError属性名称更改为其他名称，只需要在以下代码中添加以下映射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; } } ``` 通过如下代码来模拟错误 ``` int num = Convert.ToInt32("10s"); ``` 现在映射后的输出如下所示 ``` { "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 …" } } ``` 请注意APIError现在根据MapResponseObject类中定义的属性更改了模型的默认属性。 我们可以自由的选择映射任何属性，下面是映射属性相对应的列表 ``` [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)] ``` # 自定义错误架构 AutoWrapper还提供了一个APIException可用于定义自己的异常的对象，如果想抛出自己的异常消息，则可以简单地执行以下操作 ``` throw new ApiException("Error blah", 400, "511", "http://blah.com/error/511"); ``` 默认输出格式如下所示 ``` { "isError": true, "responseException": { "exceptionMessage": "Error blah", "referenceErrorCode": "511", "referenceDocumentLink": "http://blah.com/error/511" } } ``` 当然我们可以自定义错误格式 ``` 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; } } ``` 然后我们可以通过如下代码进行引发我们错误 ``` throw new ApiException( new Error("An error blah.", "InvalidRange", new InnerError("12345678", DateTime.Now.ToShortDateString()) )); ``` 输出格式如下所示 ``` { "isError": true, "error": { "message": "An error blah.", "code": "InvalidRange", "innerError": { "requestId": "12345678", "date": "10/16/2019" } } } ``` # 使用自定义API响应格式 如果映射满足不了我们的需求。并且我们需要向API响应模型中添加其他属性，那么我们现在可以自定义自己的格式类，通过设置UseCustomSchema为true来实现，代码如下所示 ``` app.UseApiResponseAndExceptionWrapper(new AutoWrapperOptions { UseCustomSchema = true }); ``` 现在假设我们想在主API中响应中包含一个属性SentDate和Pagination对象，我们可能希望将API响应模型定义为以下格式 ``` 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; } } ``` 通过如下代码片段进行测试结果 ``` public async Task Get() { var data = await _personManager.GetAllAsync(); return new MyCustomApiResponse(DateTime.UtcNow, data, new Pagination { CurrentPage = 1, PageSize = 10, TotalItemsCount = 200, TotalPages = 20 }); } ``` 运行后会得到如下影响格式 ``` { "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 } } ``` 但是从这里要注意一旦我们对API响应进行自定义，那么就代表我们完全控制了要格式化数据的方式，同时丢失了默认API响应的某些选项配置。但是我们仍然可以利用ApiException()方法引发用户定义的错误消息 如下所示 ``` [Route("{id:long}")] [HttpPut] public async Task Put(long id, [FromBody] PersonDTO dto) { if (ModelState.IsValid) { try { var person = _mapper.Map(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()); } ``` 现在当进行模型验证时，可以获得默认响应格式 ``` { "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