ViewComponent exception handling

Question

Hi,

What is the correct way to handle exceptions in a view component? I would like the user to end up being redirected to an error page.

My ViewComponent looks like this :

public async Task<IViewComponentResult> InvokeAsync()

{

StandingsViewModel model = new StandingsViewModel();

try

{

//model populated here

return View(model);

}

catch

{

//redirect to error screen, pass parameter

_httpContextAccessor.HttpContext.Response.Redirect("/Home/Error/VC123");

return View(new StandingsViewModel());

}

}

And the action in the controller where the view component is used is in this format :

public IActionResult Index()

{

try

{

HomeIndexModel model = new HomeIndexModel();

//model populated here

return View(model);

}

catch (Exception ex)

{

IPAddress ip = Helpers.Extensions.GetIPAddress(Request.Headers,

Request.HttpContext.Connection.RemoteIpAddress);

ErrorLog el = new ErrorLog

{

Controller = ControllerContext.ActionDescriptor.ControllerName,

Action = ControllerContext.ActionDescriptor.ActionName,

IPAddress = ip.ToString(),

ErrorDateTimeUtc = DateTime.UtcNow,

ExceptionType = ex.GetType().Name,

ErrorMessage = ex.Message,

StackTrace = ex.StackTrace,

UserId = (User != null) ? _userManager.GetUserId(User) : null

};

_ctx.ErrorLogs.Attach(el);

_ctx.ErrorLogs.Add(el);

_ctx.SaveChanges();

//redirect to error screen, pass parameter

return RedirectToAction("Error", "Home", new { id = "HM097" });

}

}

Is this the right way to do this? Should I catch exceptions in the view component and redirect from there, or is it possible to do it in the view that is using the view component and if so how?

Thanks in advance!

Answer 1

A ViewComponent must not perform redirects or handle navigation. Redirecting from a ViewComponent can lead to broken responses and unpredictable behavior because ViewComponents execute during view rendering. let exceptions from the ViewComponent bubble up and handle them centrally using global exception handling.

Correct implementation:

public async Task<IViewComponentResult> InvokeAsync()

{

    var model = new StandingsViewModel();

    return View(model);

}

Configure global exception handling:

In Program.cs or Startup.cs: app.UseExceptionHandler("/Home/Error");

This ensures any unhandled exception, including those thrown inside a ViewComponent, will be redirected to the error page.

Handle logging and error code generation in the Error action. This provides centralized logging,

Consistent error handling, clean separation of responsibilities.

public IActionResult Error()

{

    var exceptionDetails = HttpContext.Features.Get<IExceptionHandlerFeature>();

    return View();

}