I have an iOS app that uses Core Location to get the user's location, which pops up the request for permission on the first attempts. However, there are moments where the user will not be able to operate the screen, so at these times I don't want to ask for a location. I check before each call to CLLocationManager startUpdatingLocation, and set map views to not show the user location. The problem is that there is still something trying to access the use location, as the permissions popup is still shown, and I am unable to find where this happens.
So, what other actions could trigger this? And, probably most useful: is there a way I can set a symbolic breakpoint on something that fires always whenever access to the current location is requested? I tried setting one on [UIAlertView show], but that doesn't fire, presumably because the alert is shown by the system, rather than my app?
Related
I'm working on an app that utilizes Core Motion. During the initial onboarding of the app, it asks the user for permission, and we basically want to update the UI based on the response of that popup (Allowed/Denied). Where for notifications and location services this seems easy to do, it doesn't like a request permission API exists for Core Motion, instead it just triggers the popup when starting updating on a manager like we do now:
let motionManager = CMMotionActivityManager()
motionManager.startActivityUpdates(to: OperationQueue.main) {
// do stuff
}
Ideally I want to be able to detect a change in CMMotionActivityManager.authorizationStatus(), but so far haven't been able to come up with a working solution other than implement a timer that checks this property, which I don't feel is a particularly nice solution.
I tried making either authorizationStatus() or the manager as a whole an observable using Combine but that doesn't seem to trigger any updates.
If the user has denied permission, she cannot then grant permission without going to the Settings app. So you don't need to check on a timer. It should suffice to check at app launch and on notifications applicationWillEnterForeground and didBecomeActiveNotification.
I have a setting that is shown to the user on first run, and depending on this setting the app will either call requestAlwaysAuthorization or requestWhenInUseAuthorization. If the user said no to this setting and later on changes it to yes, I want the app to try and "upgrade" the location authorisation to Always, but I don't get a popup. Is this possible?
When the user launches the app for the first time and attempts to login, they are prompted with the iOS dialog - "Turn On Location Services".
I need to capture when the user clicks "cancel". Is there a Notification sent? If so, what is its name? I've been unable to locate it.
The CLAUthorizationStatus is kCLAuthorizationDenied when Location Services are Disabled OR the user clicked "Don't allow". When the user clicks "Cancel", it does not fire the authorizationChange event. When user clicks "Cancel", the app just hangs.
Short answer: You can't catch that notification. You can infer about the user choice and act consequently by using CLLocationManager methods (the longer answer below).
Longer answer:
Firstly, welcome on Stack Overflow. Before kindly posing your question, and trying to be collaborative with people that are here to help, it's a good idea to search if somebody else previously posed the same question.
A brief search gave (just to mention some of them):
How to handle “Cancel” button on Alert pop up for Location services
How to get location services to reprompt the user for location permission if they accidentally refused it?
locationManager:didFailWithError: not called if user Location Services are off
How to prompt user to turn on Location Services…again
How can I prompt the user to turn on location services after user has denied their use
How to ask permission from user for second time to allow to access the current location?
Now, let's try to summarize them all, starting from iOS docs:
If your app relies on location services to function properly, you should include the UIRequiredDeviceCapabilities key in the app’s Info.plist file. You use this key to specify the location services that must be present in order for your app to run. The App Store uses the information in this key from preventing users from downloading apps to devices that do not contain the listed features.
Important: If your app uses location services but is able to operate successfully without them, do not include the corresponding strings in the UIRequiredDeviceCapabilities key.
So, if your app really needs to access the user's position you should add location-services and eventually gps to UIRequiredDeviceCapabilities.
Then, somewhere in your code - when needed, you have to check if the location services are enabled.
[CLLocationManager locationServicesEnabled]
they may be disallowed for three reasons:
The user can disable location services in the Settings app.
The user can deny location services for a specific app.
The device might be in Airplane mode and unable to power up the necessary hardware.
You are interested in the second case: the user refused to allow your app to use the location services.
Again, from the docs:
Important: In addition to hardware not being available, the user has the option of denying an application’s access to location service data. During its initial uses by an application, the Core Location framework prompts the user to confirm that using the location service is acceptable. If the user denies the request, the CLLocationManager object reports an appropriate error to its delegate during future requests. You can also check the application’s explicit authorization status using the authorizationStatus method.
[CLLocationManager authorizationStatus]
That may return:
kCLAuthorizationStatusNotDetermined if the user has not yet made a choice regarding whether this application can use location services.
kCLAuthorizationStatusRestricted this application is not authorized to use location services. The user cannot change this application’s status, possibly due to active restrictions such as parental controls being in place.
kCLAuthorizationStatusDenied The user explicitly denied the use of location services for this application or location services are currently disabled in Settings.
kCLAuthorizationStatusAuthorized This application is authorized to use location services.
If[CLLocationManager locationServicesEnabled] returns NO and you attempt to start location services anyway (i.e. calling [locationManager startUpdatingLocation]), the system prompts the user to confirm whether location services should be re-enabled. Given that location services are very likely to be disabled on purpose, the user might not welcome this prompt.
I suppose you know, and did all the previous steps (I'm only sure you checked the authorizationStatus). You refused to show us the significant code of your app so I can only suppose the overall logic behind. Now you said your app hangs. This should be because you didn't catch the error properly? Catching the error is the way to re-prompt the user, if you wish.
After calling [locationManager startUpdatingLocation], if not authorized, your delegate should define a locationManager:didFailWithError: in order to catch the kCLErrorDenied.
- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
You may show, at this point, a UIAlert to insist asking the user to give you access to its position, or trigger a change in the UI or whatever you like.
Final notes
I hope you understand why I was asking for the code: the reason was to offer you an alternative solution instead of reply "You can't catch the 'Cancel' notification".
If this answer does not satisfy your question please elaborate why you need to catch the pushing of the "Cancel"/"Do not allow" button, so we can provide alternatives.
Clearly my advice is to not annoy people to death by continuously ask them for enabling location services if they don't want.
Post scriptum: Maybe that the answer looks pedantic and obvious in certain parts if not all to you, but we are here to provide answers also for future readers.
I've got an iOS app in which it starts differently if the user has been logged in through Facebook account or not.
So the application flow is as follows:
1- I call app delegate, which creates a navigationController and shows it.
2- In the root view controller, it checks if the user is logged in or not. By default (for example during the first boot) it loads view controllers as not logged in, showing only contents for not logged user. if the user is logged with Facebook account it sends requests to a server and shows the contents for logged in user. The requests start with didupdatelocation delegated method, from which it gets the current location.
3- there are many places in which the app asks if you want to log in. If the user gets correct login, it creates a new navigation controller, as in app delegate, and displays it. The problem is that in this way it doesn't call the method didupdatelocation, and so it doesn't get current location and doesn't make any request to server.
How can you suggest me to solve the problem?
Your design should not rely on didUpdateLocation to be called. This method is called at non-predictable intervals by the system.
One way to force it to call however, is to stop the locationManager and start it again.
startUpdatingLocation
stopUpdatingLocation
However, I recommend you consult the CLLocationManager Class Reference and re-design your login check accordingly.
If we try to access the user's location, iOS will tell the user that our application wants to use their location.
If I do this
[locationManager startUpdatingLocation];
An alert will show.
However, that only happens once.
It looks like some variable or default must have been set up once that display pops out.
How do I reset those default so that next time my app wants to use location users will be asked again?
Google map can displays that again and again.
It's Apple that asks them for permission, not you
Translation: You don't have any control over that part of the process. The little popup:
is only shown by Apple when you first ask for it - so the user always feels in control. After they accept for the first time, Apple assumes they are OK with your app getting their location information from their device, and won't show it again*.
*Unless they specifically go into Settings and disable Location Services for you app.
It's only showed on the first time and there's nothing you can do to change that. What you can do is ask your users to allow it on settings.
You can check if your app has permissions by checking:
[CLLocationManager locationServicesEnabled]
From the docs:
The user can enable or disable location services from the Settings application by toggling the Location Services switch in General.
You should check the return value of this method before starting location updates to determine whether the user has location services enabled for the current device. If this method returns NO and you start location updates anyway, the Core Location framework prompts the user to confirm whether location services should be reenabled.