[Bug] exception not catched into the modal component

Describe the bug

I use a ilogger global exception handler and I call services from my component which is in my modal. when a service throws an exception I can’t catch it from my global handler.

it works fine all the application except for the exceptions of the services called by my component in the modal

Is there a way to catch the exception that thrown inside the modal? Is it a different thread? A cascading problem?

** Code **

My Ilogger

    public interface IUnhandledExceptionSender
    {
        event EventHandler<Exception> UnhandledExceptionThrown;
    }

    public class UnhandledExceptionSender : ILogger, IUnhandledExceptionSender
    {

        public event EventHandler<Exception> UnhandledExceptionThrown;

        public IDisposable BeginScope<TState>(TState state)
        {
            return null;
        }

        public bool IsEnabled(LogLevel logLevel)
        {
            return true;
        }

        public void Log<TState>(LogLevel logLevel, EventId eventId, TState state,
            Exception exception, Func<TState, Exception, string> formatter)
        {
            if (exception != null)
            {
                UnhandledExceptionThrown?.Invoke(this, exception);
            }
        }
    }

    public class UnhandledExceptionProvider : ILoggerProvider
    {
        UnhandledExceptionSender _unhandledExceptionSender;
        private ITechnicalLogger _technicalLogger;
        private IToastService _toastService;

        public UnhandledExceptionProvider(UnhandledExceptionSender unhandledExceptionSender, ITechnicalLogger technicalLogger, IToastService toastService)
        {
            _unhandledExceptionSender = unhandledExceptionSender;
            _technicalLogger = technicalLogger;
            _toastService = toastService;
        }

        public ILogger CreateLogger(string categoryName)
        {
            return new UnhandledExceptionLogger(categoryName, _unhandledExceptionSender, _technicalLogger, _toastService);
        }

        public void Dispose()
        {
        }

        public class UnhandledExceptionLogger : ILogger
        {
            private readonly string _categoryName;
            private readonly UnhandledExceptionSender _unhandeledExceptionSender;
            private ITechnicalLogger _technicalLogger;
            private IToastService _toastService;

            public UnhandledExceptionLogger(string categoryName, UnhandledExceptionSender unhandledExceptionSender, ITechnicalLogger technicalLogger, IToastService toastService)
            {
                _unhandeledExceptionSender = unhandledExceptionSender;
                _categoryName = categoryName;
                _technicalLogger = technicalLogger;
                _toastService = toastService;
            }

            public bool IsEnabled(LogLevel logLevel)
            {
                return true;
            }

            public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception exception, Func<TState, Exception, string> formatter)
            {
                if (exception != null)
                {
                   //All exceptions catched here except from my modal component
                    _technicalLogger.Error("Error occurred", exception);
                }
            }

            public IDisposable BeginScope<TState>(TState state)
            {
                return new NoopDisposable();
            }

            private class NoopDisposable : IDisposable
            {
                public void Dispose()
                {
                }
            }
}

Program init

var unhandledExceptionSender = new UnhandledExceptionSender();
            var unhandledExceptionProvider = new UnhandledExceptionProvider(unhandledExceptionSender, technicalLogger, null);
            builder.Logging.AddProvider(unhandledExceptionProvider);
            builder.Services.AddSingleton<IUnhandledExceptionSender>(unhandledExceptionSender);

App.razor

<CascadingBlazoredModal>
    <Router AppAssembly="typeof(Program).Assembly">
        <Found Context="routeData">
            <RouteView RouteData="routeData" DefaultLayout="typeof(MainLayout)" />
        </Found>
        <NotFound>
            <LayoutView Layout="@typeof(MainLayout)">
                <p>Sorry, there's nothing at this address.</p>
            </LayoutView>
        </NotFound>
    </Router>
</CascadingBlazoredModal>

Method to open the modal

public async Task Edit(int id)
        {
            var parameters = new ModalParameters();
            parameters.Add(nameof(AgencyEdit.AgencyId), id);
            var editModal = Modal.Show<AgencyEdit>("Edit", parameters, new ModalOptions
            {
                Animation = ModalAnimation.FadeIn(1)
            });

            var result = await editModal.Result;
            if (!result.Cancelled)
            {
                await RefreshList();
            }
        }

My Edit component into the modal

public partial class AgencyEdit : ComponentBase
{
        [Inject]
        private IAgencyService _agencyService { get; set; }

        [Inject]
        private IToastService _toastService { get; set; }

        [CascadingParameter] BlazoredModalInstance BlazoredModal { get; set; }

        [Parameter]
        public int AgencyId { get; set; }

        public AgencyViewModel Agency { get; set; }

        protected override async Task OnInitializedAsync()
        {
            await base.OnInitializedAsync();
            Agency = new AgencyViewModel();
        }

        protected override async Task OnParametersSetAsync()
        {
            if (AgencyId > 0)
            {
                Agency = await _agencyService.GetAgency(AgencyId);
            }
        }

        public async void HandleValidSubmit()
        {
              // This method throws an exception !
                await _agencyService.AddAgency(Agency))
        }
}

[adrienbarde]

Hi @adrienbarde

I can reproduce your issue with that project. I don’t immediately see the issue, but have you had a look at this. It seems logging/exception handling/catching in Blazor is not very mature yet, so maybe something is just going wrong there?

ok thank your help, i will migrate to 5.0.0-preview2, it seems to be resolve my issue

[larsk2009]

It seems like this has been solved, so I will close this issue. If it isn’t fixed yet, let us know!