What causes this iOS permission prompt for "use Bluetooth for new connections"?

Question

Since iOS13, our app which uses BLE beacons for location, now gets two Bluetooth related permissions prompts.

The first one is understandable and expected:

The second prompt is not expected, and we don't know why it's happening.

FYI the app is currently compiled with the previous iOS SDK/XCode.

Communize

Answer 1

I think that this second prompt is a new iOS13 variation on "please enable Bluetooth" and that it appears because the user has set Bluetooth to "off" in the control centre, but not turned Bluetooth fully off in Settings.

The description of "use Bluetooth for new connections" seems to correspond to the "partially enabled" state (white button in control centre).

This second prompt can be stopped using the CBCentralManagerOptionShowPowerAlertKey: @(NO) option to the CBCentralManager init call.

Communize

Is there a way to set a value of CBCentralManagerOptionShowPowerAlertKey in the Info.plist file? – Fascia

It’s an API parameter not an info.plist entry? – Calculated

oh, alright then. Just wanted to double-check. Thanks – Fascia

Then if the Bluetooth is partially enabled then the prompt will always appear? – Goring

No, the prompt is still controlled by the power alert option (as far as I remember). Whether its partially or fully enabled just controls which kind of prompt appears. – Calculated

Answer 2

By default, when Bluetooth is disabled every time you create a CBCentralManager this pop-up will appear.

By disabled I mean the bluetooth radio turned off. you can do this via the control center, or in your phone's settings. this is different from denying an app bluetooth permissions.

If you add a CBCentralManagerOptionShowPowerAlertKey to the options when creating your CBCentralManager this pop-up will not appear.

Swift:

let manager = CBCentralManager(delegate: nil,
                               queue: nil,
                               options: ["CBCentralManagerOptionShowPowerAlertKey": 0])

Objective-C:

[[CBCentralManager alloc] initWithDelegate:self
                                     queue:nil
                                   options:@{CBCentralManagerOptionShowPowerAlertKey: @0}];

Unexceptional

Which kind of "disabled" do you mean? In the control centre, or in settings? – Calculated

by disabled I mean the bluetooth radio turned off. you can do this via the control center, or in your phone's settings. this is different from denying an app bluetooth permissions. – Unexceptional

They are not the same thing. Turning it off in settings does fully turn the bluetooth radio off. Turning it off in control centre leaves the radio on, and still allows some connections to work like Apple Watch or headphones. It just prevents any new connections. – Calculated

Answer 3

Swift 5 / To disable "APP_NAME would like to use Bluetooth for new connections" alert use options when instantiating CBCentralManager:

var centralManager = CBCentralManager(delegate: YOUR_DELEGATE?, queue: YOUR_QUEUE?, options: [CBCentralManagerOptionShowPowerAlertKey: 0])

Springwood