How can I resolve the current dialog stack in my Bot Framework MessagesController?

Question

In my Messages controller, I want to check whether a certain dialog is on the stack for the incoming message prior to dispatching it to a dialog, so that I can suppress certain conditional behavior. I tried resolving IDialogStack as per this answer, like so:

public async Task<HttpResponseMessage> Post([FromBody] Activity incomingMessage)
    {
        try
        {
            if (incomingMessage.Type == ActivityTypes.Message)
            {
                using (var scope = DialogModule.BeginLifetimeScope(Conversation.Container, activity))
                {
                    var stack = scope.Resolve<IDialogStack>();
                }
                ...

Here's the modules being registered in my Global.asax:

    private void RegisterBotModules()
    {
        var builder = new ContainerBuilder();

        builder.RegisterModule(new DialogModule());
        builder.RegisterModule(new ReflectionSurrogateModule());
        builder.RegisterModule(new DialogModule_MakeRoot());

        builder.RegisterModule<GlobalMessageHandler>();

        builder.RegisterModule(new AzureModule(Assembly.GetExecutingAssembly()));

        var store = new TableBotDataStore(/*connection string*/);
        builder.Register(c => store)
            .Keyed<IBotDataStore<BotData>>(AzureModule.Key_DataStore)
            .AsSelf()
            .SingleInstance();

        builder.Register(c => new CachingBotDataStore(store, CachingBotDataStoreConsistencyPolicy.ETagBasedConsistency))
            .As<IBotDataStore<BotData>>()
            .AsSelf()
            .InstancePerLifetimeScope();

        builder.Update(Conversation.Container);
        var config = GlobalConfiguration.Configuration;
        config.DependencyResolver = new AutofacWebApiDependencyResolver(Conversation.Container);
    }

However, I get the following Exception:

{"An error occurred during the activation of a particular registration. See the inner exception for details. Registration: Activator = IDialogTask (DelegateActivator), Services = [Microsoft.Bot.Builder.Dialogs.Internals.IDialogStack, Microsoft.Bot.Builder.Dialogs.Internals.IDialogTask], Lifetime = Autofac.Core.Lifetime.CurrentScopeLifetime, Sharing = Shared, Ownership = OwnedByLifetimeScope ---> Object reference not set to an instance of an object. (See inner exception for details.)"

With inner Exception:

"Object reference not set to an instance of an object."

" at Autofac.Core.Resolving.InstanceLookup.Activate(IEnumerable1 parameters)\r\n at Autofac.Core.Resolving.InstanceLookup.<Execute>b__5_0()\r\n at Autofac.Core.Lifetime.LifetimeScope.GetOrCreateAndShare(Guid id, Func1 creator)\r\n at Autofac.Core.Resolving.InstanceLookup.Execute()\r\n at Autofac.Core.Resolving.ResolveOperation.GetOrCreateInstance(ISharingLifetimeScope currentOperationScope, IComponentRegistration registration, IEnumerable1 parameters)\r\n at Autofac.Core.Resolving.ResolveOperation.Execute(IComponentRegistration registration, IEnumerable1 parameters)\r\n at Autofac.Core.Lifetime.LifetimeScope.ResolveComponent(IComponentRegistration registration, IEnumerable1 parameters)\r\n at Autofac.ResolutionExtensions.TryResolveService(IComponentContext context, Service service, IEnumerable1 parameters, Object& instance)\r\n at Autofac.ResolutionExtensions.ResolveService(IComponentContext context, Service service, IEnumerable1 parameters)\r\n at Autofac.ResolutionExtensions.Resolve[TService](IComponentContext context, IEnumerable1 parameters)\r\n at Autofac.ResolutionExtensions.Resolve[TService](IComponentContext context)\r\n at Progressive.CQBot.Controllers.MessagesController.d__0.MoveNext() in D:\Source\Repos\QUO_Cognitive_Quoting\Src\CQBot\Controllers\MessagesController.cs:line 33"

Is the advice in the linked answer deprecated? Is there some module registration I'm missing? I would appreciate any direction!

Answer 1

The BotData needs to be loaded in scope before resolving the IDialogStack.

Please try the following:

using (var scope = DialogModule.BeginLifetimeScope(Conversation.Container, activity))
{
    var botData = scope.Resolve<IBotData>();
    await botData.LoadAsync(new System.Threading.CancellationToken());

    var stack = scope.Resolve<IDialogStack>();
}