Detecting unsaved changes

Is there a method to determine if there are unsaved changes?

Writing some Javascript to alert the user upon navigation.

[bago]

Solutions:

A) saved state

• change the save code so to store in memory the "latest saved json".
• upon navigation run an "viewModel.exportJSON()" and compare it to the "last saved json".

B) dirty flag

• add a "dirty" boolean to the viewModel
• made dirty = false when you save
• make dirty = true when you make any change (maybe in a plugin working like the "undomanager plugin".
• upon navigation check the dirty flag.

Both could be made generic enough to be included in the main baseline... I don't plan to have time soon... maybe I can work on something similar in the next months. Contributions are welcome.