Thank you for writing.
provides interface for appointment factories and is not related anyhow to the dialogs. You should implement and use such factory only if you are adding custom fields to the appointments (e.g. you are inheriting from the Appointment
As to showing custom EditRecurrenceDialog
, the event handler you have posted seems correct and I am not sure if there is something else you are missing. I am attaching a small sample project which demonstrates the implementation of such scenario. Hope you find it useful.
Please let me know if you need further assistance.
All the best,
the Telerik team