How is AllowBackgroundUpdates supposed to work and how does it work, or modify MobileLocation.AuthorizationStates.AuthorizedAlways? If I set the authorizationState to Always is
AllowBackgroundUpdates (= True) even necessary?
Anywhere I put MyLocation.AllowBackgroundUpdates = True it immediately crashes the app…
Are you asking permission first?
Yup
Crashes even when I use:
If MyLocation.AuthorizationState = MobileLocation.AuthorizationStates.AuthorizedAlways Then
myLocation.AllowBackgroundUpdates = True
end if
This is in Xojo 2023r4
That’s not what I mean. There’s a RequestAuthorization method that needs to be called as well as a string that needs to be set to indicate why you want the user’s location.
You can set the string by selecting the iOS build target and then on the advanced panel turn on Location under Capabilities and click the options button and set the strings.
Sorry I was incomplete in my previous post. Here is
If MyLocation.AuthorizationState = MobileLocation.AuthorizationStates.AuthorizedAlways Then
' we've got our requested authorization state, start getting LocationChanged events
if GPSon and mbTileSet <> nil then MyLocation.Start
Else
' we don't have authorization yet, so ask for it
MyLocation.RequestUsageAuthorization(MobileLocation.UsageTypes.Always)
End If
If MyLocation.AuthorizationState = MobileLocation.AuthorizationStates.AuthorizedAlways Then
myLocation.AllowBackgroundUpdates = True
end if
Even though I am requesting alsays, the system gives me “AppInUse” (I know this because the message shown is the string I use for while app in use and not the string that I use for always access location and because in the System Setting locations permissions it shows while app in use for my app. This may be because a previous version of my app only used while in use for locations permissions. But even if I go to system settings and deny permission to access locations, the next time I run my app it asks only for permissions while in use, not always.
And if I manually setting locations permissions for my app to always in the system settings and then run the above code, it crashes on the device when it gets to myLocation.AllowBackgroundUpdates = True
Your code is still incorrect. RequestUsageAuthorization Is an asynchronous call and you have to wait until the event fires before you can call anything else. Once the user responds, the AuthorizationStateChanged event should fire and tell you what they selected.
Thanks, Greg, for your insight. Right now, request authorization is in the Open Event of MyLocation (the Xojo example project has it in the open event of the Window that contains MyLocation). If I understand correctly,
If MyLocation.AuthorizationState = MobileLocation.AuthorizationStates.AuthorizedAlways Then
myLocation.AllowBackgroundUpdates = True
end if
should go in the AuthorizationStateChanged event but the request authorization can stay in the open event?
Okay, I’m using the example project “Location” in the iOS examples folder.
In the Screen1 Opening Event, where it request authorization, I change AppInUse to Always:
If MyLocation.AuthorizationState = MobileLocation.AuthorizationStates.AuthorizedAlways Then
// we've got our requested authorization state, start getting LocationChanged events
myLocation.Start
Else
// we don't have authorization yet, so ask for it
myLocation.RequestUsageAuthorization(MobileLocation.UsageTypes.Always)
MyLocation.Start
End If
The iOS system message only shows that I asked for AppInFront not Always.
I add an AuthorizationStateChanged Event to MyLocation and in that event, I add:
if state = MobileLocation.AuthorizationStates.AuthorizedAlways then
me.AllowBackgroundUpdates = True
end if
“me.AllowBackgroundUpdates = True” hard crashes in the simulator and on a device every time. No Xojo error message in the simulator crash, the app simple quits.
So it appears that I’m being even more clueless than my average state but I just don’t see where/how to use AllowBackgroundUpdates to turn on background updates.
By the way, the Visits Project in the iOS examples folder immediately crashes the simulator on launch as well without any modification. It appears to have AllowBackgroundUpdates set as well from the comments but I’m not sure where that is done.
I’m happy to report this as a bug if I’m not using it correctly but I’d like to know whether it really is a bug, first.
You should look at the console logs for the simulator you are using. The answer will probably be there.
Here’s the crash report. It happens as soon as
if myLocation.AuthorizationState = MobileLocation.AuthorizationStates.AuthorizedAlways then
myLocation.AllowBackgroundUpdates = True
end if
is executed in the AuthorizationStateChanged event of myLocation.
As far as I can tell, this is a Xojo bug but, if anyone has a snippet of code that actually works to allow background updates, I’d love to see it.
-------------------------------------
Translated Report (Full Report Below)
-------------------------------------
Incident Identifier: 0D3F63E0-8879-44B1-8944-5C13B2CDC124
CrashReporter Key: 67CDF09E-C984-4750-FCEE-D466BA1C6166
Hardware Model: Mac14,15
Process: iOSLocation.debug [69886]
Path: /Users/USER/Library/Developer/CoreSimulator/Devices/40FE56B4-5529-4794-8662-571B179498CE/data/Containers/Bundle/Application/EDB35A17-2C58-4E1C-B72A-82064FDE0608/iOSLocation.debug.app/iOSLocation.debug
Identifier: com.example.ioslocation
Version: 1.0.0 (1)
Code Type: ARM-64 (Native)
Role: Foreground
Parent Process: launchd_sim [15690]
Coalition: com.apple.CoreSimulator.SimDevice.40FE56B4-5529-4794-8662-571B179498CE [18945]
Responsible Process: SimulatorTrampoline [943]
Date/Time: 2024-01-18 09:59:16.9708 -0500
Launch Time: 2024-01-18 09:59:16.7520 -0500
OS Version: macOS 14.2.1 (23C71)
Release Type: User
Report Version: 104
Exception Type: EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Termination Reason: SIGNAL 6 Abort trap: 6
Terminating Process: iOSLocation.debug [69886]
Triggered by Thread: 0
Last Exception Backtrace:
0 CoreFoundation 0x1803e1174 __exceptionPreprocess + 216
1 libobjc.A.dylib 0x180193384 objc_exception_throw + 56
2 Foundation 0x180746648 _userInfoForFileAndLine + 0
3 CoreLocation 0x183af8d40 0x183ae6000 + 77120
4 iOSLocation.debug 0x1020c0d24 MobileLocation.AllowBackgroundUpdates.Set%%o<MobileLocation>i4b + 20
5 iOSLocation.debug 0x10214f570 Screen1.Screen1.MyLocation_AuthorizationStateChanged%%o<Screen1.Screen1>o<MobileLocation>i8<MobileLocation.AuthorizationStates> + 604 (/Screen1:236)
6 iOSLocation.debug 0x10214fd6c Delegate.IM_Invoke%%o<MobileLocation>i8<MobileLocation.AuthorizationStates> + 68
7 iOSLocation.debug 0x10214fdc8 AddHandler.Stub.2%%i8<MobileLocation.AuthorizationStates> + 72
8 rbframework.dylib 0x1034d7a34 0x103458000 + 522804
9 CoreLocation 0x183b05470 0x183ae6000 + 128112
10 CoreLocation 0x183b04dd0 0x183ae6000 + 126416
11 CoreLocation 0x183ae98f0 0x183ae6000 + 14576
12 LocationSupport 0x188dd1ea0 0x188dcd000 + 20128
13 CoreFoundation 0x180350030 __CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__ + 20
14 CoreFoundation 0x18034f2f4 __CFRunLoopDoBlocks + 408
15 CoreFoundation 0x180349bb0 __CFRunLoopRun + 764
16 CoreFoundation 0x1803493a8 CFRunLoopRunSpecific + 572
17 GraphicsServices 0x18c03c5ec GSEventRunModal + 160
18 UIKitCore 0x184d937ac -[UIApplication _run] + 992
19 UIKitCore 0x184d982e8 UIApplicationMain + 112
20 rbframework.dylib 0x1034fae44 0x103458000 + 667204
21 iOSLocation.debug 0x102060c68 Xojo._RuntimeRun + 36
22 iOSLocation.debug 0x1021519c4 _Main + 656 (/#main:42)
23 iOSLocation.debug 0x102150c70 main + 36
24 dyld_sim 0x1028e1ca0 start_sim + 20
25 dyld 0x1022d60e0 start + 2360
26 ??? 0x320a000000000000 ???
Why are you not using the “state” parameter from the event?
I’ve tried it both ways and either one produces a hard crash
Did you set the strings for getting the users location under Capabilities?
Yes, the strings are set and I use a different one for Always versus when in front…
I’ve submitted a feedback issue (#75341)
In the capabilities again, under “background” did you set Location in there?
Bingo! That seems to have done the trick. Thanks very much, Greg!