Mvc: ActionExecutingContext Exception handling

[hikalkan]

Hi,

I have a simple action filter like that:

``` C#
public class AbpUowActionFilter : IAsyncActionFilter
{
...

public async Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next)
{
    using (var uow = _unitOfWorkManager.Begin())
    {
        await next();
        await uow.CompleteAsync();
    }
}

}
```

What I want is simple: If no exception occurs, then I complete the unitofwork/transaction.

The problem is that: Exceptions are internally handled by MVC (https://github.com/aspnet/Mvc/blob/5339a3e0cee469b856c11344613f8ab8c3c802ba/src/Microsoft.AspNetCore.Mvc.Core/Internal/ControllerActionInvoker.cs#L386) and my CompleteAsync code is executed even there is an exception after this filter.

I checked ActionExecutingContext if there is an Exception property that I can check to know if there is an exception. Unfortunately, there is not such a property. ActionExecutedContext has such a property (https://github.com/aspnet/Mvc/blob/ee2cfa1963ee7f8195130d41330f94d4622ca89a/src/Microsoft.AspNetCore.Mvc.Abstractions/Filters/ActionExecutedContext.cs#L47) but I want to implement IAsyncActionFilter, not IActionFilter. Is there a possibility to know if there is an exception in IAsyncActionFilter?

[rynowak]

In an IAsyncActionFilter calling next() returns an ActionExecutedContext. So:

``` C#
public class AbpUowActionFilter : IAsyncActionFilter
{
...

public async Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next)
{
    using (var uow = _unitOfWorkManager.Begin())
    {
        var executed = await next();
        if (executed.Exception != null && !executed.ExceptionHandled)
        {
            await uow.CompleteAsync();
        }
        else
        {
            await uow.RollbackAsync();
        }
    }
}

}
```

[hikalkan]

Thank you. You can close this issue since I got my answer :)

[derekgreer]

... except commit on no exception regardless of if the exception is handled already or not.

    if (executed.Exception == null)
    {
         // commit
    }
    else
     {
         //  rollback
     }

[rynowak]

Thanks, updated