office js - Outlook JS Addin - Compose form - how to check if the event/message is saved? -

is there way in compose form of outlook add-in (office.js) check if object behind form (in case calendar event) saved?

check itemid; if it's undefined message not stored, , if exists message draft. please refer office.context.mailbox.item.itemid

edit: don't want delete answer completely, because of valuable input in comments tim wan. there no way identify if message persisted on exchange , check itemid doesn't work in compose forms.