Safeguard y.js reconnect

[juliusknorr]

Thinking about the y.js web socket reconnect that happens to cause some troubles, I think we should also ensure that a reconnect is only reusing the existing y.js state on the frontend if we know for sure that the document hasn't been reset in the meantime on the server (as this might still happen on the background job).

My suggestion would be to store the timestamp of the initial creation in oc_text_documents and make sure to compare that in the reconnect logic somehow. If the initial creation time is different we reload the full editor.

@max-nextcloud What do you think about that?

[max-nextcloud]

the document hasn't been reset in the meantime on the server (as this might still happen on the background job).

Would the reset also happen if there's an active session in the database? My thinking thus far was that the constant awareness updates will keep the session last_seen current.

[juliusknorr]

I think you're right, in all cases where we clean up document data we ensure that sessions are either no longer there or they are also removed so any follow up would trigger a reload of the document.