Need to get the value before the transaction

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1

Hi, is there a way to get the value before and after the transaction?
For example if I have a Y.Map { ‘my-key’ : ‘my_val’ } and after transaction it becomes
{ ‘my-key’ : ‘new_val’ }, how can I know what previous value was there (in the example it’s my_val) given then I am hooked to on(‘update’ … ) event

2

There are beforeTransaction and afterTransaction events on the Doc:

Also the observe event on the Y.Map contains the old value in ymapEvent.changes.keys.get(key).oldValue:

3

I’m trying to do the same thing, but for a yText shared type. I see in the yText documentation examples a reference to oldValue but that doesn’t actually seem to be accessible in practice.

Is there a way to get the text that is being deleted from a transaction/event? The transaction has already been applied by the time the observer is called, so I can’t even look up the text at the position in the ytext.

Thanks!