Perform a redirect in Constructor

Question

How can I make a Response.Redirect() in a class builder?

public class FarmaciaController : Controller{

    public FarmaciaController(){
        if(!userLogin.usuarioTemPermissao("Farmacia"))
         Response.Redirect("~/PortalFarmacia/Home");
    }  

}

Answer 1

Redirect in the constructor can give some problems due to context besides not being a good practice, one solution is you create a custom attribute for your action and overwrite the method OnActionExecuting to validate.

public class ValidarPermissaoActionAttribute : ActionFilterAttribute
{
    public override void OnActionExecuting(ActionExecutingContext filterContext)
    {
        base.OnActionExecuting(filterContext);

        if (/* verificar se o usuario tem permissão */)
        {
            filterContext.Result = new RedirectToRouteResult(new RouteValueDictionary(new
            {
                controller = "PortalFarmacia",
                action = "Home"
            }));
        }
    }
}

And in his Controller

public class FarmaciaController : Controller
{
    [ValidarPermissaoAction]
    public ActionResult Index()
    {
        // Essa action só vai ser executada se a validação tiver ok
        return View();
    }
}