See if the user is near a location? Swift 4

Question

I would like to be-able to see if the user is in a 5 km radius of the other location in Swift 4.

For example:

User Location: 37.785834, -122.406417
Other Location: -117.564011, 48.302353

Thanks for anyone who helps!

You can use `CLLocation` `distance(from: CLLocation)` instance method — Leo Dabus, Sep 16 '18 at 01:31
`let user = CLLocation(latitude: 37.785834, longitude: -122.406417) let other = CLLocation(latitude: 37.8, longitude: -122.5) let distance = user.distance(from: other) // 8391.307900456288` — Leo Dabus, Sep 16 '18 at 01:32
What measurement is this? 8391.307900456288, kilometers, meters? — Oscar, Sep 16 '18 at 01:34
It's in meters. Doesn't hurt to check the documentation: https://developer.apple.com/documentation/corelocation/cllocation/1423689-distance — Code Different, Sep 16 '18 at 02:07

ezaji · Accepted Answer · 2018-09-16T03:22:42.907

You can detect when the user enters or leaves a geographic region automatically by using Region Monitoring feature provided by CLLocationManager.

Start monitoring the circle region around the specified coordinate:

let center = CLLocationCoordinate2D(latitude: 37.785834, longitude: -122.406417)
// Make sure the app is authorized.
if CLLocationManager.authorizationStatus() == .authorizedAlways {
    // Make sure region monitoring is supported.
    if CLLocationManager.isMonitoringAvailable(for: CLCircularRegion.self) {
        // Register the region.
        let maxDistance = locationManager.maximumRegionMonitoringDistance
        let region = CLCircularRegion(center: center, 
             radius: 5000.0, identifier: "YourRegionID")
        region.notifyOnEntry = true
        region.notifyOnExit = false

        locationManager.startMonitoring(for: region)
    }
}

Handle a region-related notification (enter notification in this example) by implementing suitable method from CLLocationManagerDelegate:

func locationManager(_ manager: CLLocationManager, didEnterRegion region: CLRegion) {
    if let region = region as? CLCircularRegion {
        // your logic to handle region-entered notification
    }
}

See if the user is near a location? Swift 4

1 Answers1