Set content when returning result in ExceptionFilterAttributeRSS

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  b.dev

  Member

  2 Points

  35 Posts

  Set content when returning result in ExceptionFilterAttribute

  Oct 03, 2019 11:38 AM|b.dev|LINK

  Hi

  I want to return 401 when handling exception in my app:

  public override void OnException(ExceptionContext context)
  {
  if (context.Exception is UnauthorizedTransactionSystemException)
  {
  
  var response = new HttpResponseMessage(HttpStatusCode.Unauthorized)
  {
  Content = new StringContent("Authorization exception while accessing ST."),
  ReasonPhrase = "User is not authorized. Please contact your administrator."
  };
  
  context.HttpContext.Features.Get<IHttpResponseFeature>().ReasonPhrase =
  "User is not authorized. Please contact your administrator.";
  
  }
  }

  I want to set the content of the result as I can set it with HttpResponseMessage, but I do not know how. Here is how I set HttpResponseMessage:

   var response = new HttpResponseMessage(HttpStatusCode.Unauthorized)
                                     {
                                         Content = new StringContent("Authorization exception while accessing."),
                                         ReasonPhrase = "User is not authorized. Please contact your administrator."
                                     };

• • Reply
  Rena Ni

  Participant

  1030 Points

  344 Posts

  Re: Set content when returning result in ExceptionFilterAttribute

  Oct 04, 2019 09:53 AM|Rena Ni|LINK

  Hi b.dev,

  If you use ASP.Net Core,you need to know that Authorization filters run first in filters pipeline when you add Authorize attribute.If you fail to authorize,you would get 401 by default and it would not get into the Exception Filter.

  I find you use UnauthorizedTransactionSystemException.Did you custom Authorization and not use default Authorization?

  Reference:

  https://docs.microsoft.com/en-us/aspnet/core/mvc/controllers/filters?view=aspnetcore-2.2#filter-types

  Best Regards,

  Rena

  MSDN Community Support
  Please remember to click "Mark as Answer" the responses that resolved your issue.
  If you have any compliments or complaints to MSDN Support, feel free to contact MSDNFSF@microsoft.com.
• • Reply
  b.dev

  Member

  2 Points

  35 Posts

  Re: Set content when returning result in ExceptionFilterAttribute

  Oct 04, 2019 10:11 AM|b.dev|LINK

  Hi

  We do not use ASP.NET authorization. We call a service inside the action that I want to apply the filter and that service might throw excpetion which indicates unauthorized exception. 

• • Reply
  Rena Ni

  Participant

  1030 Points

  344 Posts

  Re: Set content when returning result in ExceptionFilterAttribute

  Oct 08, 2019 07:53 AM|Rena Ni|LINK

  Hi b.dev,

  You could change your code like below:

  public class CustomExceptionFilterAttribute : ExceptionFilterAttribute
  {
      public override void OnException(ExceptionContext context)
      {
              
          if (context.Exception is UnauthorizedAccessException)
          {
              var response = new HttpResponseMessage(HttpStatusCode.Unauthorized)
              {
                  Content = new StringContent("Authorization exception while accessing ST."),
                  ReasonPhrase = "User is not authorized. Please contact your administrator."
              };
              context.HttpContext.Features.Get<IHttpResponseFeature>().ReasonPhrase = "User is not authorized. Please contact your administrator.";
              context.Result = new HttpResponseMessageResult(response);
              base.OnException(context);
          }
      }      
  }
  public class HttpResponseMessageResult : IActionResult
  {
      private readonly HttpResponseMessage _responseMessage;
  
      public HttpResponseMessageResult(HttpResponseMessage responseMessage)
      {
          _responseMessage = responseMessage; // could add throw if null
      }
  
      public async Task ExecuteResultAsync(ActionContext context)
      {
          context.HttpContext.Response.StatusCode = (int)_responseMessage.StatusCode;
          using (var stream = await _responseMessage.Content.ReadAsStreamAsync())
          {
              await stream.CopyToAsync(context.HttpContext.Response.Body);
              await context.HttpContext.Response.Body.FlushAsync();
          }
      }
  }

  Result:

  

  Best Regards,

  Rena

  MSDN Community Support
  Please remember to click "Mark as Answer" the responses that resolved your issue.
  If you have any compliments or complaints to MSDN Support, feel free to contact MSDNFSF@microsoft.com.