react-native-geolocation-service: Enable enableHighAccuracy in iOS only returns position after timeout

With build 5.0 and enableHighAccuracy=true the position on iOS devices is only returned after the timeout is reached. Im my case this is after 10 seconds. When I disable enableHighAccuracy it works fine. This is a new behaviour with build 5. Before it worked as expected. This only happens on real devices. In the simulator it immediately returns the location. I am using the following options for getCurrentPosition:

{
  distanceFilter: 100,
  enableHighAccuracy: true,
  timeout: 10000,
  maximumAge: 60 * 5 * 1000
}

I tested this on several iOS devices and the behaviour is the same.

About this issue

Original URL
State: closed
Created 4 years ago
Reactions: 13
Comments: 31 (12 by maintainers)

Most upvoted comments

Went through requestLocation iOS docs which this library uses for getCurrentPosition. According to them, this function will try to get GPS data for the accuracy set. Under the hood enableHighAccuracy uses kCLLocationAccuracyBest which is the highest accuracy possible. GPS algorithms use lot of data to calculate GPS position like wifi, bluetooth, mobile signal and GPS. Hence calculating GPS location with accuracy kCLLocationAccuracyBest will vary from place to place.

According to the docs it will return GPS location if it satisfies the desired accuracy or after timeout. Hence for your error cases it looks like the device is taking around 10 sec to get the desired accuracy, so this delay.

Earlier this library used to start a GPS continuous update request and will stop on first result and send the response in getCurrentPosition. This should have returned first location earlier, but this might not be of required accuracy. This is how continuous GPS location request works.

So, you have two options to solve this problem,

Lower your timeout and hope you get the desired accuracy. Better solution than using enableHighAccuracy:false (which will use like city level accuracy).
Start watchPosition urself and stop, kind of complicated for simple use cases but still you have the option.

There are other accuracy options in iOS native API, but that is not supported in this library.

ravirajn22 on Sep 24, 2020

kCLLocationAccuracyReduced is supported only in iOS 14. For iOS < 14, should we fall back to use threeKilometers ?

Agontuk on Dec 1, 2020

@rayj10 you can use the master branch to try out accuracy option, it’s already implemented. API may change, so use it only to test the feature.

setting maximumAge to N means for the next N/1000 seconds if you request location, it’ll return the previous result.

setting distanceFilter to N means it’ll notify location change only when user moves at least N meter

Agontuk on Oct 16, 2020

v5.1.0 published with accuracy level support, doc has been updated.

Agontuk on Nov 26, 2020