How to properly query LibreOffice Online if a document was changed?

Hi! In a application context, where LOOL resides in a iframe, I’d like to query LOOL’s instance if that document was changed by the user.

WOPI Protocol specifies the “Edit_Notification” PostMessage for this purpose but is not implemented in LOOL, so I tried to inspect map global variable and found the property _everModified that keeps the information I need:


My perception is that using this variable is not safe because it can be removed anytime so I wonder how to properly query LibreOffice Online about this?

I built LOOL forcing versions:

LOOLWSD - 3.2.2 (git hash: ffc419a)
LOKit - Collabora OfficeDev 5.3-47 (git hash: 6855f7c)