Exception Handling with Structuremap

Question

Is there anyway to recover gracefully in an ASP.NET MVC application if the database is not found for some reason when I try to get an instance of my NHibernate Session from Structuremap?

public static class StructureMap
{
    private static Configuration Cfg
    {
        get
        {
            var configuration = new Configuration().Configure(Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "nhibernate.config"));
            configuration.SetProperty(NHibernate.Cfg.Environment.ConnectionStringName, "MyConnectionString");
            return configuration;
        }
    }

    public static void ConfigureStuctureMap()
    {
        ObjectFactory.Initialize(x =>
             {
                 x.ForRequestedType<ISessionFactory>()
                     .CacheBy(InstanceScope.Singleton)
                     .TheDefault.Is.ConstructedBy(Cfg.BuildSessionFactory);

                 x.ForRequestedType<ISession>()
                     .CacheBy(InstanceScope.HttpContext)
                     .TheDefault.Is.ConstructedBy(c => c.GetInstance<NHibernateSessionFactory>().GetCurrentSession());

             });
    }
}

Right now the application will display a runtime error YSOD. I have a custom static html error page setup in the web config but it doesn't display even though I have the custom errors mode set to "On"

Answer 1

Catch any NHibernate/StructureMap initialization errors, and override your controller factory to handle the case when it is impossible to create a controller that depends on StructureMap-related dependencies. This will allow you to handle errors and redirect to the action/controller which does not depend on neither NHibernate nor StructureMap - either from controller factory or using [HandleError] attribute.