Offline scanning

If the signal drops at the entrance, the scanner keeps checking tickets with a list on the device. Online stays the norm: every scan goes to the server first, and only if it doesn't answer within a few seconds does the scanner check its own list. Offline scans wait on the device and are sent automatically as soon as there is signal again.

Step 1: Turn on offline scanning

On the scanner, under May scan, there is the Allow offline scanning switch. For a new scanner it is off; turn it on when you create the scanner or under Change. See Creating a ticket scanner.

Step 2: Open the scanner before the event, with signal

The list arrives on the device as soon as the volunteer opens the scanner while there is a connection. Open the scanner before the match while you have a connection, and do not close it. If you close the scanner or reload it without signal, it can't start up again until there is a connection.

Step 3: Read the status line

• Ready for offline · 312 tickets · 13:58 (green) – the list is on the device; the time is when it was fetched. With signal it refreshes every two minutes.
• Offline · list 6 min old · 7 waiting (orange) – no connection; 7 scans are waiting to be sent.
• Red – the list is older than 30 minutes, or it says "Offline list expired — scanning only works with a connection". Tickets bought or refunded in the meantime are then unknown to the device.
• Offline · no list on this device – the scanner was opened without signal.
• Offline scanning is turned off for this scanner – see step 1.

What the volunteer sees offline

• Valid ticket (checked offline) – green, let them in.
• This ticket has already been scanned. – this device has already let it in.
• This ticket was refunded or cancelled.
• No ticket for this event. – red, no button.
• Possibly just bought — ask to see the payment email. – orange, with the Let in anyway button. The ticket is newer than the list or the payment was still in progress. If the payment email checks out, let the visitor in. After syncing it is still checked; a fake ticket then shows up as invalid, with device and time. Each device can do this at most 50 times per event.
• A membership card can only be scanned with a connection. – a membership card never works offline.

Selling at the till and redeeming at the bar also only work with a connection.

With Valid ticket (checked offline) and This ticket has already been scanned., the caption Extras with this order also appears underneath offline, with the extras of the whole order, for example "+3 Parking" on each of the three tickets of one order. So hand items out per order, not per scan; see Extras with tickets. For this, the list on the device only holds the name and quantity of each extra, never names or email addresses of buyers.

What is and isn't watertight

A forged ticket doesn't get through offline either: the list on the device only contains a fingerprint of each ticket, from which no valid ticket can be made.

Two devices that are both offline can't see each other's scans. If someone shares a screenshot of one ticket, two offline entrances can both let someone in. The same device does refuse the second ticket. As soon as there is a connection again, such a double entry shows up as a conflict; see Let in twice after offline scanning.

Don't lose waiting scans

Only tap Leave scanner when the status line no longer mentions waiting scans. If scans are still waiting, the scanner asks Scans still waiting with Stay or Leave anyway. If you choose Leave anyway, those scans are lost.

Revoking devices

Each device is registered per volunteer and stays valid until 12 hours after the event ends. If a phone goes missing, revoke it on the scanner under Devices with Revoke. Offline scans the device made before it was revoked may still be sent afterwards. They are only recorded as a trail of who came in, no longer as a check-in, and appear in the statistics as "Registered after revocation".

Frequently asked questions

Does it also work if the scanner has had no signal all afternoon? Yes, but the older the list, the bigger the chance of an unknown or meanwhile refunded ticket. The line turns red after 30 minutes.

Another browser or a private window on the same phone? That counts as a different device, with its own list.

The wifi network at the entrance asks you to log in first. Is the volunteer logged out? No. An error page from such a network counts as a dropped connection: the volunteer stays logged in and the scanner falls back on the list on the device.