How to begin a dialog with a variable value as the dialog name

I setup the Event activity with the dialog name as the Activity Value, and then have an expression of =turn.activity.value in Dialog name field, but does not seem working as it results in a Null Ref exception in the BotController.cs

What would be the correct way to dynamically begin a dialog with the given name through a variable?

[EricDahlvang]

Hello @dawwa and thank you for engaging with the Composer project. Supporting the “dialogs” array in the Composer ui would be a new feature request. We’ll take this issue as a feature request and add it to the backlog for prioritization. We do not have an ETA at this time for when this feature will be available.

[anishprasad01]

@dawwa

It seems to be that there is an issue with how Composer deals with DialogSets internally. The NullReferenceException you’re getting is likely because the bot cannot find the dialog in question, and not because of any issue with the user’s input.

However, there is a workaround. This issue thread outlines a workaround that involves creating a dummy event that you never call and invoking all of your dialogs in it. Then, invoking the dialog with the input format =turn.activity.value in the Dialog name field of your original event should result in the behavior you’re looking for. Make sure to do this in the root dialog (where your event is). If you do it in a child dialog, it may not work.

Alternatively, you can go into the code view of your root dialog and add an array of dialogs to achieve the same effect without the need for a dummy event (see image below).