Data Annotation and DTOs #751

7 Answer(s)

• 

  0

  maharatha created 8 years ago

  I see you have created the IShouldNormalize interface for Input DTO , won't it be good if you implement similar stuff for normalizing or decorating the output DTO

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• 

  0

  hikalkan created 8 years ago

  Support Team

  Hi,

  I think the best thing to do for your situation is interception. So, you can intercept calls to application service. After method execution, you can get the DTO and manipulate it via your DtoManager. We use interception for authotization (before method execution) and audit logging (after method execution) for example.

  This class registers the interceptor: <a class="postlink" href="https://github.com/aspnetboilerplate/aspnetboilerplate/blob/master/src/Abp/Authorization/Interceptors/AuthorizationInterceptorRegistrar.cs#L11">https://github.com/aspnetboilerplate/as ... rar.cs#L11</a> (Initialize is called from PreInitialize of the module: <a class="postlink" href="https://github.com/aspnetboilerplate/aspnetboilerplate/blob/master/src/Abp/AbpKernelModule.cs#L46">https://github.com/aspnetboilerplate/as ... ule.cs#L46</a>)

  You can find documents on the web for Castle Windsor interceptors.

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• 

  0

  maharatha created 8 years ago

  Hi Hikalkan -

  I tried my hand with Intercepting the calls but I am unable to intercept the Async methods. Is there a way I can intercept the result of the Aync methods.

  I see some explanation in the below link :

  <a class="postlink" href="https://gist.github.com/hikalkan/1e5d0f0142484da994e0">https://gist.github.com/hikalkan/1e5d0f0142484da994e0</a>

  But these aren't helpful.

  Could you throw some light into it ? I am kind of stuck.

  Thanks, Partha

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• 

  0

  hikalkan created 8 years ago

  Support Team

  Hi,

  Could you implement it for non-async methods? Can you share some of your code and describe your problems for better help.

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• 

  0

  maharatha created 8 years ago

  internal class DTOInterceptors : IInterceptor
      {
          public void Intercept(IInvocation invocation)
          {
              try
              {
                  if (AsyncHelper.IsAsyncMethod(invocation.Method))
                  {
                      PerformASyncDTOOperation(invocation);
                  }
                  else
                  {
                      PerformSyncDTOOperation(invocation);
                  }
              }
              catch (Exception ex)
              {
                  // OnException(invocation, ex);
              }
          }
  
  
         
  
  
          private void PerformSyncDTOOperation(IInvocation invocation)
          {
              var stopwatch = Stopwatch.StartNew();
  
              try
              {
                  invocation.Proceed();
              }
              catch (Exception ex)
              {
  
                  throw;
              }
              finally
              {
                  stopwatch.Stop();
  
              }
          }
          private void PerformASyncDTOOperation(IInvocation invocation)
          {
              var stopwatch = Stopwatch.StartNew();
  
              invocation.Proceed();
  
              if (invocation.Method.ReturnType == typeof(Task))
              {
                  invocation.ReturnValue = InternalAsyncHelper.AwaitTaskWithFinally(
                      (Task)invocation.ReturnValue,
                      exception => SaveAuditInfo(stopwatch, exception)
                      );
              }
              else //Task<TResult>
              {
                  invocation.ReturnValue = InternalAsyncHelper.CallAwaitTaskWithFinallyAndGetResult(
                      invocation.Method.ReturnType.GenericTypeArguments[0],
                      invocation.ReturnValue,
                      exception => SaveAuditInfo(stopwatch, exception)
                      );
              }
          }
  
          private void SaveAuditInfo(Stopwatch stopwatch, Exception exception)
          {
              stopwatch.Stop();
  
  
  
          }
  
      }
  

  I am not doing much anything in the SyncMethods as I don't have the need. But when I try the Asyn Method I get :

  e.g. invocation.ReturnValue = Id = 13743, Status = WaitingForActivation, Method = "{null}", Result = "{Not yet computed}"

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• 

  0

  hikalkan created 8 years ago

  Support Team

  Hi,

  Your code seems fine at first look. Return value seems also normal. What exception are you getting or what's the problem here? I will create an interception document in a few days (probably today or tomorrow). If you have time, you can wait for it to understand interception better.

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• 

  0

  maharatha created 8 years ago

  That would be awesome. I can definitely wait.

  The problem is what do I do with the return value when I don't have the actual value in my return value.

  Waiting eagerly for your document.

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