I have an app which uses forge.geolocation.getCurrentPosition. It seems that at times, the location does not refresh. I can open the iOS app in one position, and then an hour later 5 miles away, open the app again (either resume, or completely close the app from the tray, and re-open) and still the old location is returned.
I am using this form
forge.geolocation.getCurrentPosition({enableHighAccuracy: true}, function (location) {})
Note that when opening/resuming the App, the GPS icon at the top DOES show up however the location returned to the javascript code is incorrect.
The above bug was reproduced on iOS 6
After opening the Maps app, and going back to my app, the correct location is finally returned.
Any idea how to fix this?
getCurrentPosition returns the best data it has at that particular time - I'd recommend calling the method a number of times until the indicated accuracy is reduced to an acceptable level.
What we might do in the future is support watchPosition so that something like https://stackoverflow.com/a/8554835 would be possible through the forge API
Related
I'm trying to reach the file which I was downloading earlier by NSURLSession. It seems I can't read the location of the file, even though I'm doing it before delegate method ends (as the file is temporary).
Still, I'm getting nil when trying to access the data under location returned from NSURLSession delegate and error 257.
The code goes as following:
- (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didFinishDownloadingToURL:(NSURL *)location {
NSError *movingError = nil;
NSData *fileData = [NSData dataWithContentsOfFile:location.path options:0 error:&movingError]; // is nil
NSLog(#"%#", movingError); // is error 257
}
What's wrong with this code..? I saw similar questions NSURLSessionDownloadTask - downloads but ends with error and iPhone - copying a file from resources to Documents gives an error but these completely doesn't apply to my case.
-- edit --
I've created a new project and pasted the very same code. It works... So:
1) In my project I'm receiving error 257, probably some configuration of the project is invalid or the fact I'm using backgroundTasks somewhere else in the app messes things up
2) Same as in 1 happens if I put the source files of this download to the external framework linked in by Carthage
3) On demo project I created (copy-pasted files used in 1 & 2) everything works corretly.
If someone has an idea what can cause the fact it isn't working - would be awesome.
Late to the discussion, but I've seen the same/similar issue and investigated.
With my investigation, what you are seeing is expected (should I say “it's observed”?).
But since I'm not 100% sure how you are using URL session, I put down below what I'm trying to do, followed by my observations (important ones only).
Also, I created a sample project and put it here as downLoader.zip. You can play and check how URL session background download works. But It's better to read thru below before trying to play, though this is fairly a long note.
A. what I'm trying to do
I'm developing kind a map app, where I need to download 1000+ of small size (0.5-150kB, mostly ~20kB) PNG files at a time. Total download size of them is ~50MB, and it takes a couple of minutes to download all of them. I think that keeping users to my app just waiting for download is bad design, so I made the app to use URL Session’s background download.
I have to admit, however, that Apple’s doc says that “Background sessions are optimized for transferring a small number of large resources that can be resumed as necessary.” So, the way I’m using background session is totally opposite. But, anyway...
B. what I've observed
Below, I’ve listed my observations and my guess of why. I should say guess since they are not documented.
(1) observation: sometimes, files that should come with didFinishDownlaodingTo don’t exist.
Temporary files are put at:
/var/mobile/Containers/Data/Application/randomHexString/Library/Caches/com.apple.nsurlsessiond/Downloads/yourName.yourApp. The randomHexString changes from app’s run to run. When the files don’t exist, the randomHexString that came with didFinishDownloadingTo is the one from the “previous” session. Now, “previous” here means the session at app’s previous run !, which clearly doesn't exist at the current session at current run.
There's another scenario for non-existent file, which is that the randomHexString is ok, but the files don't exist. This seems to happen after session cancel is requested (invalidateAndCancel) and before session becomes invalid (didBecomeInvalidWithError).
Guess: This happens especially on the development phase since we terminate the app while downloading, manually or by debugger or just by bug. It seems once the download requests are handed and accepted to the OS, the OS handles our requests even after the app quits. Note we can’t know if the OS has definitely accepted the requests or not. Even after the return from URLSessionDownloadTask:resume(), sometimes files don’t exit at the next launch and sometimes they do.
Workaround: If files don’t exist, just ignore them. In a while, “this time’s” files should come.
(2) observation: sometimes, the duplicated (same) files come with didFinishDownloadingTo.
My app converts downloaded PNG files to other format. W/in didFinishDownlaodingTo, I move temp files (== OS designated) to another my app’s directory, then spawn thread (GCD) to convert the format and delete downloaded temp files. So, the other thread (didFinishDownlaodingTo) to overwrite is an issue.
Workaround: I make list of URLSessionTask:taskIdentifier and w/in didFinishDownlaodingTo, check the duplication by retrieving the taskID list to ignore duplicated files.
(3) observation: even after the user terminated the app, OS relaunches the app again.
After the user terminated the app from task switcher, quite often, the OS relaunches the app w/ application:handleEventsForBackgroundURLSession:completionHandler.
Note the sequence of relaunch is that didFinishLaunchingWithOptions comes first as regular launch, then handleEventsForBackgroundURLSession comes next.
From user’s POV, when he/she terminated the app, that’s it, done! It looks strange even after they terminated the app, it relaunches in itself and notifies something to them. It's like a zombie.
Guess: The Apple’s document says “If the user terminates your app, the system cancels any pending tasks”. The definition of “pending tasks” is not clearly stated but I understand this is from iOS POV and not user’s or program developer’s. As guessed in (1), iOS seemed to have accepted the download requests, and they are not “pending tasks” anymore.
Workaround: I create a “flagFile” after all of download requests are handed to iOS w/ URLSessionDownloadTask:resume(), of which file means that “download is ongoing”. When users terminate the app, at UIApplicationDelegate:applicationWillTerminate, I delete the flag file. Or, if all of download requests not handed to iOS, there's no flag file. Then at app’s relaunch at UIApplicationDelegate:handleEventsForBackgroundURLSession, I check if we have the flag file. If missing, then I can assume that users terminated. Two choices here. Choice-1: I will not recreate URL session. What happens next is that iOS will terminate my app in about 20 seconds. I have no idea if this (== not creating the URL session) is a legal operation but it works. Users can launch w/in this 20 sec, so I put some more code to handle that scenario. Choice-2: I create URL session. What happens next is that iOS calls delegate methods didFinishDownlaodingTo/didCompleteWithError, followed by urlSessionDidFinishEvents. If I don't do anything here, the process (app) keeps alive indefinitely w/o any notification to users: nothing in task switcher. This is nothing more than waste of memory. The option here is to fire local notification and let users know of my app, so that they can go back to my app and can terminate (Again!), though my app clearly appears as a zombie. One issue for both choices: applicationWillTerminate may not be called in certain situation (though I've yet confirmed). At this case, flag file is left as regular ops and show zombie to users. So, the flag file method is just mitigation to the issue, but I think it works most of the time for my app.
Note the app is relaunched sometimes when it's killed by xcode debugger or killed by OS w/ bug (SEGFALUT).
(4) observation: after the app is terminated (by user, etc.) then relaunched by OS, the app is occasionally in active state (UIApplication.shared.applicationState is .active).
I want to notify the user on the download completion by local notification, but since it's active, local notification doesn't fire. So, I need to use UIAlertController instead. Therefore, I can't provide consistent user experience, and should look strange for users: most of the time local notification and very occasionally UIAlert. Note when app started in active state, it appears in task switcher.
Guess: totally no idea how this can happen. One good(?) thing is this happens only occasionally.
Workaround: seems none.
(5) observation: handleEventsForBackgroundURLSession/urlSessionDidFinishEvents is called just once.
I start the download after started background task (application.beginBackgroundTask). Then in expiration handler of beginBackgroundTask, I call endBackgroundTask. I don't know exactly why, but after endBackgroundTask, my process is still given lots of process time, so I can keep requesting download. This might be because download files keep coming w/ didFinishDownlaodingTo. To be a good citizen, I suspend to request further download, and fire local notification to user to put the app to foreground. Now, once I suspend the request, in 4-5 seconds, OS determines the URL session is over and handleEventsForBackgroundURLSession then urlSessionDidFinishEvents are called. This is one-off event. When the user put the app in foreground to resume download, then put it again in background, no handleEventsForBackgroundURLSession/urlSessionDidFinishEvents will come anymore. What's unclear to me is the definition of session's start and end. It seems the session starts at first URLSessionTask.resume(), then ends w/ timeout, which seems to be determined by URLSessionConfiguration.timeoutIntervalForRequest. However, setting large number here (1000 sec) doesn't affect anything, it's always 4-5 seconds.
Guess: no idea
Workaround: don't relay on urlSessionDidFinishEvents while the app is alive. Relay only when app relaunched by OS and at initial handleEventsForBackgroundURLSession/urlSessionDidFinishEvents.
===============
Below, I listed about the sample project (downLoader.zip). You can verify all of above with the sample.
The app has a list of download files. The number of files is 1921, and 56MB in total. They are 256x256 PNG map tile files that are located in a server managed by Geo Spatial Information Authority of Japan (GSI). After downloaded, they are moved to Library/Cache/download. If your device is jail-broken, you can view them w/ Filza.
crash itself to test relaunch
emulate background task expiration
logging to file since debugger doesn't work after relaunch by OS. The file is in Documents, can be moved to PC.
Do play with the real device. Simulator doesn't relaunch the app.
Project built w/ Xcode 8.3.3 and tested w/ iphone6+/9.3.3 and iphone7+/10.3.1
To see if app relaunched w/ xcode, go to Debug/Attach to Process menu and see if downLoader is listed.
===============
I think URL session background download behaves trickily, especially at relaunch. We need to consider at least the observations I listed above, or the app users will get confused.
I found same error code 257 from online users feedback.In the error scene, the location always refers to a strange bundle identifier:com.sdyd.SDMobileMixSmart. And I guess this's an apple system bug.
I am currently using the Xamarin geolocation plugin found here:
https://github.com/jamesmontemagno/GeolocatorPlugin
To perform location services in an app I am building using Xamarin Forms (PCL).
I believe I have added in the relevant permission settings to allow for this.
The GPS works great while the app is active and locked (but with app in the foreground). However when the app is pushed to the background on iOS by clicking the "home" button, it still tracks the user and highlights the "App is Using Your Location" message as I would expect, however after a certain amount of time between 30-40 minutes, this message disappears, and the GPS appears to stop tracking the user until they bring the app back to the foreground.
Once the app has been brought to the foreground, it can be backgrounded once again for another 30-40 minutes to repeat the cycle.
I have ensured that the locator object allows background updates:
public static Plugin.Geolocator.Abstractions.IGeolocator locator;
locator = CrossGeolocator.Current;
locator.AllowsBackgroundUpdates = true;
locator.DesiredAccuracy = 20;
A call to .PausesLocationUpdatesAutomatically shows that this is false (which I believe is the default).
Edit
I have the following keys to info.plist:
NSLocationWhenInUseUsageDescription
NSLocationAlwaysUsageDescription
And enabled background location updates:
However I have not enabled background fetching as Girish has in the answers, is this something I need to do?
Please check whether you have enabled the background mode for location update.
If I start my application in airplane mode, I am expecting my delegate location manager object to have a fail since it should ben unreachable.
However, the method "locationManager:didUpdateLocations" gets called instead, and a location is given, but appears to have some internal objects to "nil".
The whole thing brings a consequent crash when the location object is passed and used.
Shouldn't I receive a fixe error if the device is in airplane mode, with the method "locationManager:didFailWithError:" being invoked?
This doesn't happen if the app is already working.
FYI, in devices running iOS 8.3 or greater, GPS is not disabled when airplane mode is enabled.
Just for whoever will be asking the same question (that can be found elsewere here on stackoverflow asked in different ways), The CLLocationManager has an internal cache that expires after a bit.
This means that if you go on Airplane mode and ask for a location, the location manager sends you the most recent it fixed UNTIL it clears the cache after a few minutes (almost 30), then it gives a location error.
Mi crash was because of something else, so the object returned works just fine.
If you want to be sure the fix has been done exactly when you asked for it, there's a "timestamp" property on a cllocation object that could be compared with [NSDate date] to understand if the returned location is "fresh" or cached.
I have a strange problem. After I logged in with the standard SPLoginViewController, I save the username and the credential. After I startup again, I try to call:
[[SPSession sharedSession] attemptLoginWithUserName:
existingCredential:
On the iOS Simulator (iOS 6.0), it works just fine. On my iPhone (iOS 6.0.1), it does not. SPSession is logging in exactly five minutes after I called the attemptLogin method. SPSession is also logging in when I put my app in the background.
Does anyone know more about this and maybe a solution?
Thanks
It appears there's a known bug in libspotify where sp_session_process_events() will sometimes return excessively high values in next_timeout. I've seen values such as 300100 and 300195 come out of the routine.
One workaround is to set your wait to the max of next_timeout and 50. (Or 100 or whatever your heart desires.) See https://github.com/spotify/cocoalibspotify/issues/140
I wish Spotify would start a known-issues list for libspotify. I wasted over a day trying to dig this one out. Hopefully this post will save someone else the same fate.
I am testing the new Google-powered Firebase, and have implemented remote notifications and crash reporting. I am, however, having massive problems with getting Analytics to work.
I track events with FIRAnalytics.logEventWithName(...) and save user pproperties with FIRAnalytics.setUserPropertyString(...). However, no matter what I do, no data shows up in the Firebase Analytics Console.
Well, I do receive some events, but those are not sent by me (like first_open and session_start). Also, this data seems to drop in after a very long time.
Furthermore, when I track events and save user data, I receive the following:
Upload task scheduled to be executed in approx. (s): 3102.294599890709
This seems really strange - Firebase waiting almost an hour before trying to send the next batch of data must be a bug, or is it configurable? When I waited that extremely long delay out, data was sent...but does not show up.
Firebase events are batched together and uploaded once every hour in order to prevent excessive battery drain on the devices. On iOS when you background the app before the 1h upload target the events will be dispatched at this time in the background.
You can enable debug logging for iOS (https://firebase.google.com/docs/analytics/ios/events#view_events_in_the_xcode_debug_console) to see when events are uploaded in debug console.
Once the events are uploaded there is delay at about 3h before the data will show up in the Firebase Analytics dashboard. Also the default day range excludes "today" so you only see events from yesterday. You can switch the date picker to include Today if you like to see the latest events.
The main reason to delay/batch data uploading is to save battery. Each time the network is used the device mobile network modem is put in hi power mode and stay in this mode for a while. If network is used regularly it has sever impact on the battery life. By batching the uploads together and delaying the upload the impact on the battery is significantly reduced.
In Swift it should be like:
FIRAnalytics.logEvent(withName: "SignUp", parameters: ["user_id": userid, "user_name": username])
To view this event in Firebase:
Go to Firebase console → Analytics tab
Click on DebugView tab; your Events are shown there
To view this event in Xcode:
In Xcode, select Product → Scheme → EditScheme
Select Run from left Menu
Select Arguments tab
In the Arguments Passed on Launch, add -FIRAnalyticsDebugEnabled
One dash only!!
Note that -FIRAnalyticsDebugEnabled has only ONE dash in front of it.
If you are not receiving events in console, it may be because you are not following naming convention, as I experienced if there is a space in event name it will never show up in the console like following:
mFirebaseAnalytics.logEvent("Add Camera", bundle);
But when you remove the space like following:
mFirebaseAnalytics.logEvent("Add_Camera", bundle);
Now you will see events in console, after approximately 3 hours.
Application will dispatch the data to console in following cases:
1- Data is more than an hours old
2- App goes into the background
You can watch this tutorial for more information:
Getting Started with Firebase Analytics on iOS: Events - Firecasts
Another thing to check is making sure your logging entries in the Arguments Passed on Launch are correct. They should start with a - e.g
-FIRAnalyticsDebugEnabled
and not
FIRAnalyticsDebugEnabled
I wasted an hour the other day wondering why nothing gets logged.
React-Native App (IOS/Android)
I had the same problem, debugView wasn't working, and streamView glitches a few times, the best way ive found to test my events was to logEvents with my createPageEvent() and then
the important thing is to put the app into background after logging the events, they will show up almost in realtime on firebase events or in streamView (check this article to see when events are sent to firebase)
events are only sent after 1 hour since they have been logged or immediately if you put your app in background.
import firebase, { RNFirebase } from 'react-native-firebase';
export default class AnalyticsService {
static async initialize() {
firebase.analytics().setAnalyticsCollectionEnabled(true);
}
static async createPageEvent(screen: string) {
firebase.analytics().setCurrentScreen(screen)
firebase.analytics().logEvent(`open_${screen}`)
}
}
the result is this in streamView almost realtime ->
Now you can start building funnels and stuff
first_open, session_start are listed by Firebase as Automatically collected events.
I can not help you with the extreme upload task delay you encounter on your custom events.. but Firebase Analytics is less than a week old and it may be just a bug on their side.
I found this StackOverflow question which mention the same debug lines but related to Google App Measurement or old Google Mobile Analytics SDK.
Also, be aware that Firebase Console won't show events in real-time (source):
You can view aggregrated statistics about your events in the Firebase console dashboards. These dashboards update periodically throughout the day. For immediate testing, use the logcat output as described in the previous section.
Just a simple note here: according to this little video https://www.youtube.com/watch?v=5pYdTgSkW5E after playing with your simulator you must press the home button on the Xcode, otherwise the data will not be sent to the server.
The most common problem most of the people are facing is the firebase is not logging events even though everything is working perfectly fine
This is what i found in there docs
If you need to deactivate Analytics collection permanently in a version of your app, set FIREBASE_ANALYTICS_COLLECTION_DEACTIVATED to YES in your app's Info.plist file. Setting FIREBASE_ANALYTICS_COLLECTION_DEACTIVATED to YES takes priority over any values for FIREBASE_ANALYTICS_COLLECTION_ENABLED in your app's Info.plist as well as any values set with setAnalyticsCollectionEnabled.
To re-enable collection, remove FIREBASE_ANALYTICS_COLLECTION_DEACTIVATED from your Info.plist. Setting FIREBASE_ANALYTICS_COLLECTION_DEACTIVATED to NO has no effect and results in the same behavior as not having FIREBASE_ANALYTICS_COLLECTION_DEACTIVATED set in your Info.plist file.
So you have to remove FIREBASE_ANALYTICS_COLLECTION_DEACTIVATED from your google-servicesinfo.plist file to make analytics work
Make sure your device is not set to battery save mode. In this mode events may be accumulated and sent only once in a while, even if you run firebase in debug mode as explained by others.
It takes too much time to update events in Firebase. Probably it is done once a day. See iOS or Android logging of Firebase events.
You can enable verbose logging to monitor logging of events by the SDK
to help verify that events are being logged properly. This includes
both automatically and manually logged events.
You can enable verbose logging as follows:
In Xcode, select Product > Scheme > Edit scheme...
Select Run from the left menu.
Select the Arguments tab.
In the Arguments Passed On Launch section, add
-FIRAnalyticsDebugEnabled.
The next time you run your app, your events will display in the Xcode
debug console, helping you immediately verify that events are being
sent.