I am using the react-native-geolocation-service package, and everything works like a charm. But now I am required to track a users location both in the foreground and in the background. I was wandering if the watchPosition method supports background location watching or is it just when in the app? and if it doesn't support it, what would be the alternative?
Thanks
I've used it in the past and it's not straightforward. I tried with the package you mentioned and a few others. I've settled up for the react-native-background-geolocation.
You might encounter problems when switching from the background to the foreground (assuming you also need to track the location in the foreground). They can be fixed by adding a Listener.
Related
Firstly, apologies for the slightly open ended questions but I can't find the info I'm looking for in other questions.
I'm trying to understand the lifecycle of a RN app on both iOS and Android. I understand the app bootstraps when you first start it and stays running while the phone is alive, but what happens when the user switches to a different app and comes back, or their screen times out then they switch it back on? It would be really annoying if the app restarted just because they briefly switched to check their email.
My specific use case (not particularly important to this generic question but included for context) is that I'm trying to build a game with socket.io connections and I'm wondering if I can hook into events to see if the app has been in the background or if I even need to. I have found a way of forcing a restart which may be necessary at some points, but I'd rather just try to reconnect things that have disconnected if I can find out when that happens.
Any push in the right direction would be appreciated.
The app doesn't restart when it goes in the background as you describe. The app keeps its state and the user sees the last screen they visited.
You should have a look at react native's AppState
https://facebook.github.io/react-native/docs/appstate
Using AppState you can addEventListeners that capture the change of the app's state like when going to background.
Of course there are also some problems here...
You can't capture the "kill "event. You can only detect if the app is sent to the background but unfortunately you can't detect when the user chooses to "kill" the app
You can't run any code while your app is in the background. This might be serious in your case but you should evaluate it. For example if you have a timer and you sent the app to the background then the timer stops.
I used react-native-camera on my iOS app and now trying to add Focus, Brightness and Zoom controls to it. So far I was unable to come up with a solution. Any idea how to do this?
I tried to find an option in different react native camera packages. Also posted in their git repos for help. Finally tried this post: https://medium.com/react-native-development/react-native-camera-app-with-live-preview-saturation-and-brightness-filters-d34535cc6d14 Where they take a photo from the camera every 5 milliseconds and adjust its brightness which seems to be very unstable and it makes the app crash.
It is not possible to use the focus and zoom functionalities with react-native-camera.
Unluckily the focus api has many bugs and the zoom functionalities will not render fast enough with javascript.
Maybe a solution is not using react-native-camera and instead just writing an intent to open the default camera application
The following app uses this solution, all the camera functionalities work perfectly.
Could they re-open the issue as it seems to not be solved?
Developers may need to review all the open issues to estimate the project deadlines.
Do compiled Expo.io React Native applications support "Always On" background location tracking, even when the app is not in use?
Expo just implemented Background Location
Instead of using the watchPositionAsync method, you will have to utilize TaskManager.defineTask method to register the background task out outside of the React event loop. Then, start the task with Location.startLocationUpdatesAsync.
Short answer is no. Quoting the "Why not expo" page:
Expo apps don’t support background code execution (running code when
the app is not foregrounded or the device is sleeping). This means you
cannot use background geolocation, play audio in the background,
handle push notifications in the background, and more. This is a work
in progress.
You will need to detach your app and add this behavior yourself, still doing so you lose some of the expo capabilities.
I'm building my first mobile app and am loving what React Native has to offer. One major disadvantage I've encountered is that the Navigator does NOT unmount the scene when a new scene is pushed on the stack. This makes some sense as this is probably necessary for transitions to happen smoothly.
My app uses a video background and seems like other apps using large media files may encounter a similar issue of high and unnecessary resource usage due to this behavior. Maybe a better approach would be to unmount the scene after transition and remount before popping?
I wonder if others have experienced similar issues and may have some feedback. I've already tried ExNavigator and React-Native-Redux-Router. These libraries are just not mature enough for my use cases and seem to have trouble working with Hot-Reloading.
Thanks for reading and replying.
I wouldn't use React-Native-Redux-Router, its not mainted and was taken over with React-Native-Router-Flux, i used to use RNRF, but have swapped to exponents ex-navigation (https://github.com/exponentjs/ex-navigation), and stay away from Navigator if you're going to start wanting more "complex" apps, as it is no longer maintained, though it does work still.
Which ExNavigator did you use because exponents one is well maintained and extremely fluid so far for what I have been doing, and should fit for most use cases.
If you want to stick with Navigator have you tried replace(route) or the resetTo(route) though you won't have transitions
I'm developing an app which uses ibeacon to determine if the user entered a specific region.
Now I'm using the CoreLocation framework to implement this geofencing-based feature.
I've read the document below.
https://developer.apple.com/library/mac/documentation/CoreLocation/Reference/CLLocationManager_Class/CLLocationManager/CLLocationManager.html
in which the Apple is saying that:
"In iOS, the regions you register with the location manager persist between launches of your application. If a region crossing occurs while your iOS app is not running, the system automatically wakes it up (or relaunches it) in the background so that it can process the event. When relaunched, all of the regions you configured previously are made available in the monitoredRegions property of any location manager objects you create. "
I discovered that it's true just before the ios 7.
From ios 7, An app will be waken-up from background but it will actually no longer could be re-launched from terminated-state (slided out from the task manager which displayed by double-clicking the home button).
If it's due to the Apple's policies, why does Apple not update the above official document?
So I'm thinking of an ios7's bug because the Reminder App (a built-in app) is also not relaunched in ios7 even though it's relaunched in ios6.
Is this issue due to Apple's policies? or an ios7's bugs?
It takes me more than 2 days to google for a solution.
Any ideas for this issue?
The documentation is simply out of date. This is intended behavior in iOS7. Apple produced a video explicitly discussing this change. The idea is that if the user explicitly terminates the app, the user does not want it running. See this thread.
Is this such a big deal? How often will users really do this? Remember, if users are annoyed by you app, they can always uninstall it, too. This was true in iOS6.
iOS 7.1 reversed this policy. That is even if the user kills your app the iOS still launches your app upon crossing the region.