Automatic data synchronization

[simon-krucinin-applifting]

The data synchronization should happen on foreground and the dialog should block the UI until the sync completes (should be truly modal). Otherwise there's a risk the data will be modified locally while changes are still retrieved from the server and there will be conflicts.

The main synchronization method is manual -- the user simply knows best when to update, as it takes a while.

For convenience (and mostly getting last minute changes), the synchronization should be triggered automatically on these occasions:

1. After application launch
2. After application resumes to foreground
3. After turning on wi-fi

These shouldn't happen more often than once an hour. It means on these conditions it will be tested whether it is the first update or the last successful update happened an hour ago or earlier, and if so, the synchronization will run (blocking the user interaction).