About the observe & observeDeep across the fields of Y.Doc

Hi, everyone. I have a basic question here:

There had an existed ydoc persisted in the DB.

It has two fields: “foo” and “bar”.

One peer defined the ydoc.getMap(‘foo’).observe(fooHandler);

and then this peer sync the ydoc via WebSocket protocol (e.g y-websocket ),when fooHandler is invoked, can I ensure the bar of ydoc had already arrived client?