09 – Synchronization

Accounts such as Google or iCloud are synced directly with the respective provider. Local calendars and task lists can additionally be synchronized across multiple devices through your own storage. That’s what this chapter is about.

How synchronization works

Aperio stores your local data as a change log and reconciles it through a storage location that you choose – for example WebDAV, Dropbox, your Google account’s Drive, or another folder shared between your devices. There is no Aperio server; your data stays with you.

Setting up synchronization

In Aperio a storage location is an account like any other: you add it under Settings → Accounts, and the synchronization settings only ask which of your accounts holds the dataset.

1. Open the settings and go to Accounts.
2. Add an account for your storage location (e.g. WebDAV, SFTP, FTPS or Dropbox) and enter its address and credentials. Two entries need no account of their own: a folder on this device is part of Aperio itself, and Google Drive rides on a Google account you may already have for your calendars. For either, skip this step and pick it in the next one. Google Drive is not a separate entry: a Google account can hold the dataset itself, so if you already have one for your calendars, skip this step and pick it in the next one.
3. Switch to Synchronization. Under Sync target you’ll find exactly the accounts that can hold a dataset.
4. Pick the one you want in the list and choose Sync through …. Aperio probes the connection before the choice is saved — if it fails, nothing changes.
5. Set up the same storage on your second device. Both devices now share the same state.

On the very first launch the setup wizard asks for the storage location directly — that is also where you decide whether to adopt an existing dataset or start a new one.

If Aperio cannot start syncing through the chosen account after a restart — a locked keychain, a credential that is no longer there, a server fingerprint not confirmed on this device, or a missing plugin — the sync target says so on that account and offers Try … again for it. Pressing that names the actual reason and, where the repair is a confirmation, offers it right there. Disconnect stays available as well.

Protocols that identify a server by its key — SFTP, for one — ask you to confirm its fingerprint the first time, and refuse anything that does not match afterwards. The confirmed fingerprint is shown on that account, with Forget pin next to it. Drop it when you know the server’s key has changed for a legitimate reason, such as a reinstall: the next connection then asks you to confirm the new one. The pin belongs to this device alone and is never sent anywhere.

Which account a device uses is a device-local decision: the accounts themselves travel between your devices, the choice of target does not. So a laptop can reach the same dataset over the internet while a desktop reaches it over a share on the local network.

Reconciliation and conflicts

• Reconciliation happens automatically in the background and on startup.
• You can also trigger a reconciliation manually.
• If two devices edit the same entry, Aperio detects the conflict and resolves it in a comprehensible way, or asks which version should win.
• Settings travel too, and they arrive while the app is running: change a task setting on your phone and the open desktop window picks it up with the next reconciliation, no restart. If the settings page happens to be open, the change is announced.

Your devices

Every device that connects to your dataset registers itself there. Settings → Synchronization → Devices shows you the list and lets you keep it in order.

Device name. Enter what this device should be called on your other devices — “Work PC”, “Phone”. Without a name it shows up as a long string that tells nobody which device is meant. Aperio suggests the name your computer or phone already goes by; it is only stored once you press Save device name. The name belongs to this device alone and reaches the others on the next round.

Last seen. Each row says when that device last completed a round. Devices that have never reported in from a version that records it read as “unknown” — never as an invented date.

Removing devices. After a few reinstalls or test devices, the list holds entries with no device behind them any more. Those you can remove. What happens, and what does not:

• No data is deleted. Only the entry that counts this device as a participant goes.
• Old entries genuinely cost something: when Aperio cleans up, it keeps old log files until every registered device has read them. An entry with nothing behind it keeps them forever.
• You cannot really get this wrong. If the device is still running, it simply registers again on its next round.
• The device you are sitting at cannot be removed — it would register itself again immediately. To take this device out of syncing, Disconnect is the right route.

End-to-end encryption & credentials

In the synchronization settings you can turn on end-to-end encryption with a password. The storage then only ever sees encrypted data – the password never leaves your device, and without it the data cannot be recovered (so keep it somewhere safe).

When encryption is on, your account credentials (passwords, tokens) are synced encrypted as well, so your accounts work on every device without re-entering them. This also covers accounts you created before turning encryption on — their credentials are backfilled automatically when you enable it. Without encryption, credentials stay on each device only. If you turn encryption back off, they are removed from the sync store and kept locally only.

Note: External accounts (Google, iCloud, Outlook, Vikunja, Todoist) do not need this setup – they synchronize through their own service. The synchronization described here only concerns your local calendars and lists.

Screen-reader note: The status of the last reconciliation (time, success or error) is shown in the synchronization settings and is announced through a live region when it changes. Conflict dialogs are marked up as dialogs and are fully operable by keyboard.

Summary

You can synchronize your local data across devices through your own storage and know how conflicts are handled. To finish, let’s look at keyboard shortcuts.