I need to track users first and last coordinates scheduled.
For example:
I set to track location from 10.00AM to 12.00AM and I need to store first location(at 10.00AM) and last location(at 12.00AM). I try to use background fetch, but I havent idea to make that work.
I need only this two points. How I can take them?
I cant use server and notifications
Use a silent push notification to trigger background processing, then starting location updates might work.
You'd need get permission from the user to get location updates always, and you'd need to request background time when the push notification came in.
Related
Say I want to perform a background task, like upload some data, at a given date and time after the user has quit my app. So the app is killed, but I still want to run a task later on.
Is that possible? Is there a background mode to do that?
There is no background mode that awakens your application at a given time. You can use silent push notifications, but in that case you will need to have a backend that send push notifications to your app.
Also you can try using Background fetch mode, basically when the system wakes up your app you can check if the current date is the actual date that you need to execute your code.
You can utilise the Background App Refresh capability of iOS to achieve this.
Whilst you cannot specify an exact time to perform your background task, you can set a desired minimum interval to execute the task.
It's worth noting however that a user can disable this capability on both an app and device-wide level, so you should ensure that there is alternative logic to handle this situation.
I need to notify user when a certain condition is met but that condition might or might not meet in months. I need to run condition check in background (even when app terminates) so that I could detect condition is met (even if it happens after 3 months). If condition is met then I need to send notification only to a single user (not all users).
I am not sure what is the best way of doing it. Local Notification or Push Notification? I can not schedule a local notification in advance because I don’t know when it will meet the condition. I think Push notification is not needed because I am sending only one notification to only one user in several days/months.
I also need to constantly run this check in background. I know it can be run infinitely in background by using location update (significant monitoring or background navigation). But my condition checking code doesn’t actually require location updates. As far as I understand, Apple allows only location update or network related task in background (for few minutes). That's why I am thinking of putting my code in background location update code.
In my opinion , I should use local notification and put my code in background location update code so that I could check constantly if certain condition is met. This background check will schedule local notification and show it to the user who is using that device. I don’t think it is possible to schedule a push notification by code running in background.
In summary, I have following 3 questions
Should I put my code in background location update? If not, what is the right approach of running my code infinitely in background without location update?
Will Apple reject application if I put my code in background location update while location update code doesn’t actually send/receive current location?
What kind of notification should I use in this kind of situation where I send notification to a single user after months? Would you use Local Notification? or Push Notification.
Please reply. Any help is truly appreciated.
Thanks in advance.
This is a bit of a tricky problem unfortunately.
Apple won't allow you to create long-running operations in the background. As you mentioned, you can add code in the background with location updates or audio, but neither of those are very good solutions since (1) Apple will likely reject you from the app store and (2) the user will probably close the app if they notice a big locations banner at the top of their phone (or a weird background audio signal), and closing the app will kill your operation. For any truly long-running tasks it's probably best to set up a server and run a cron job or equivalent long-running operation. It's the only way you can know that the task will continue running.
Sorry, I was just answering one at a time, but as I mentioned above, yes, they'll probably reject your code for that. As a rule of thumb: if you think the Apple-created code you're using wasn't meant for what you're using it for, Apple will probably reject your app.
It sounds like you should use a remote notification. If you do use a remote notification, you'll probably want some sort of backend anyway. You could use a local notification to notify a user after a few months, but you would need to know the exact time to send it up front, which it doesn't sound like you would.
In summary: Try to build a simple BE. Maybe use Firebase Functions or something, and also build an APNS system to send pushes. In the app, tell the server to start processing the information and send the push back when it's done. The situation sounds like a perfect use case for server-side logic.
Hope that helps!
I am working on an app where I would have to implemented at least two background tasks. The scenario becomes like this, I have a web service which tells me when to start the location updates for a user. So, I would need to periodically call this service to check if it's time to start, and/or stop, user's location tracking.
So there are two background tasks, fetch and location tracking. Fetch should run periodically which defies Apple's procedure that it will monitor your app's usage and decide on it's own when to update the content. This has become my first problem, is there any way that I can avoid this? The second problem comes with the multiple tasks, how can I switch between either of them?
What is the best practice here? Dos and Don'ts?
You should use Push notifications through Apple's push servers, or you may find a service like Parse.com easier to work with. You can use the push notification to trigger or create anything in your app delegate (where you handle receiving push notifications). As #Paulw11 's comment states, you can even attach a payload(data) to a push notification and deal with it. So the first part is fire a notification to the user's device when they should start tracking and end tracking.
Most location tracking stuff using an instance of a CLLocationManager can be done via it's delegate methods. However if you want you can use it in a subclass of an NSOperation and manage it in an NSOperationQueue, see here for a tutorial:
http://www.raywenderlich.com/76341/use-nsoperation-nsoperationqueue-swift
And I suggest researching the class documentation.
Right now, my app is able to receive location updates in the background. However if the user forgets about it, and the app enters background while still receiving updates, it can in theory keep getting updates forever(i think?) until the user correctly turns it off.
Is there a way to set at timer to automatically stop the location manager, in case it is not shut down by the user?
You can use a background task with an expiration.
Read more about it here:
https://developer.apple.com/library/ios/DOCUMENTATION/UIKit/Reference/UIApplication_Class/Reference/Reference.html#//apple_ref/occ/instm/UIApplication/beginBackgroundTaskWithExpirationHandler:
I want implement a geo location notification in iOS, but just in a specific date and time.
The notification will only be launched if the user is in a certain location and at a certain date and time.
Ex.: The user is in Rio de Janeiro and is 12 o'clock.
Does anyone know how to merge these two conditions to launch a notification?
There is nothing built in that I know of -- you will have to code the logic yourself. So you will simply get geo updates from CoreLocation, and you can create a timer to give you time updates, then write some logic that execs periodically and, if the time/place matches your business rules, fire the notification. Note that the app will have to be running to accomplish this. You could send a push notification from an external server, but that server must know where the phone is, and your app must tell it.
Does this help?
It seems that this can be done elegantly as long as location updates are given precedent.
Use this CoreLocation startMonitoringSignificantLocationChanges
To get updates about location, and these updates will be able to start your app in the background (as explained in the docs). Then, in the "application:didFinishLaunchingWithOptions" method of your AppDelegate, include your logic for checking if it is the right time to send a notification (by checking with stuff in CoreData or otherwise).
There shouldn't be a need to create a timer with periodic checks. Just let CoreLocation handle the event's entry point since it'll launch your app in the background at the right location.
This is simple. I assume that you are familiar using the CLLocationManager and the MKReverseGeocoder classes. For your purpose monitoring for only significant location changes would probably be fine (even if that sometimes only happens for moving kilometers). It will help you save battery power on the device.
So, for CLLocationManager's delegate there is a method called locationManager:didUpdateToLocation:fromLocation what you can use. All you need to do is to use reverse geocoding here to determine the actual city's name depending the actual location using the MKReverseGeocoder class. Also, you have to check the local time on the device, match the two, and act accordingly (set up a local notification to wake the app from the background for example).