WiFi/Data not properly prioritized on iPhone App

[darkwater4213]

The following is copied verbatim (save for a few grammatical corrections and removal of any potentially revealing information) from the (automated) email I got from Canvas Support explaining why they can't work with this for now, but I should post this here instead.

For your records, you described your issue or question like this:
I’m on an iPhone 6s running the latest iOS as of about a month ago (I haven’t checked for updates since then). I have both Data (T-Mobile) and Wi-Fi (Wave Broadband) connected. I do have Wi-Fi assist turned on in my phone’s settings (so whenever the Wi-Fi is weak, my phone will also utilize my data connection so it’s a bit faster than molasses) Wave has been known to have random outages for no apparent reason, but this wasn’t one of them. My mom had turned off the router’s internet connectivity (yeah, we’ve got one of *those* kinds) and my phone just simply refused to connect with anything. Here’s the odd bit. It seemed like it was an iPhone problem… but everything else seemed to work relatively fine (except for the fact that nothing was actually going through). That is, other applications were completing the so-called handshake (assignable though T-Mobile) but any requests were failing, prompting an odd amalgam of success and failure messages. Canvas was probably the strangest. It couldn’t even establish an SSL connection (that’d be the secure socket layer). I’m not sure whether my phone just simply failed to make the request along both channels (Wi-Fi, which clearly failed, and Data, which probably wouldn’t have) or whether Canvas (the application) has to explicitly declare how each request is made. I don’t know enough about Swift etc. to actually tell, which is why I’m asking. At any rate, I’d appreciate it if you could somehow implement a workaround so that if Wi-Fi seems to not be working, it can ask the user if they would like to attempt a connection through Data instead (and then do so).

Best regards,
darkwater4213


-----------------------------------
User: --------
Email: ----------------------- 
Hostname: https://canvas.instructure.com
App Version: 6.17.0 (16374)
Platform: iPhone
OS Version: 15.6.1
NSErrorFailingURLStringKey: https://canvas.instructure.com/api/v1/users/self/communication_channels
_NSURLErrorFailingURLSessionTaskErrorKey: LocalDataTask <FD79651F-95A2-489C-BA3A-2C91D8CF8C42>.<20>
NSLocalizedRecoverySuggestion: Would you like to connect to the server anyway?
Enabled Features: enable_K5_dashboard
-----------------------------------

[chriscas · Accepted solution]

Hi @darkwater4213,

I found this old unanswered question while doing a cleanup of the community.

I don't think what you're experiencing is really an issue with the Canvas app itself, rather it's just the way things happen when your wifi signal is still on but disconnected form an active internet connection.  I experience similar things in my iPhone all the time if my internet connection goes down.  It would be nice if the phone realizes the WiFi internet connection was severed and would switch back to mobile data, but it's probably not easy to detect a failed internet connection from just a server that is down.  You can always manually switch WiFi off on your phone if this happens just to check things.  I don't think app makers can do anything about this in their code, but I'm not 100% sure of that.

-Chris

-Chris