Offline scan: Improve error messages and prompt offline mode for new installations

[candideu]

Hi,

I was looking forward to using the Pretix Scan app, and it's offline scanning capability was the main reason I picked the platform again for my event.

Unfortunately, valid tickets scanned with the app offline threw up a "Unable to resolve host" error. I made sure all the orders were downloaded to the device before arriving at the venue, and it didn't matter.

I'm using Pretix hosted, and scanned the tickets using the latest version of the app on a OnePlus 5t.

The event wasn't in test mode (https://github.com/pretix/pretixscan-android/issues/49)

[candideu]

I'm now seeing in the settings that offline mode has to be switched on manually. That is a shame, because I assumed it would do so automatically, or at least inform / alert new users about this feature during the setup of a new install.

Is there any way to:

• Have the app detect online/offline mode by default on new installs

• If the app is in online mode but the Wi-Fi is off: rather than throw up an "unable to resolve host" error, could the app not say, "It looks like you're offline. Switch to offline mode?" with a button that enables the setting directly? This would save the people checking in a lot of stress. The person who was managing my check-in was using the app for the first time, wasn't familiar with the platform, didn't know how to access the settings (I didn't even know there were settimgs until today), and had no idea what was wrong or how to solve the issue.

OR

• Include a prompt in new app installations, after the device is connected to the account, asking, "Will this device be used offline? Make sure to enable offline mode in the settings" with a screenshot and arrow to the settings, OR a button allowing to enable the mode and automatic detection from the very start.

[raphaelm]

First of all, sorry for the issues you had!

Offline mode is manual because it involves a risk assessment by the user: By going offline, I am accepting the risk that I will scan the same ticket as valid twice (if I'm using two devices). This risk is acceptable to some event organizers, but not to others, Therefore we will never make the offline mode automatic on new installations.

Improving the error messages is a good idea that we will look into.

[candideu]

Offline mode is manual because it involves a risk assessment by the user: By going offline, I am accepting the risk that I will scan the same ticket as valid twice (if I'm using two devices). This risk is acceptable to some event organizers, but not to others, Therefore we will never make the offline mode automatic on new installations.

That makes sense! Thank you for the explanation.

I tested the scan with offline mode afterwards, and it worked perfectly. Since I typically only use one device for scanning, I think I'll keep it to that mode. Hopefully, I'll get to use the scanning app next time around.