Is it possible to convert a string to a longitude/latitude value? I managed to convert the coordinate to a string, but I cannot find a way to revert the process
Another way to convert:
let latitude = (latitudeString as NSString).doubleValue
let longitude = (longitudeString as NSString).doubleValue
Swift 3
let lat = Double(String1)
let lon = Double(String2)
let coordinates = CLLocationCoordinate2D(latitude:lat!
, longitude:lon!)
CLLocationCoordinate2D is a double value it can convert string into double See in above example
My bad, it was a simple type. If anyone ever struggle on how to convert a string to coordinates, here's the correct syntax :
let location:CLLocationCoordinate2D = CLLocationCoordinate2D(latitude: Double(([longitudeString] as NSString).doubleValue), longitude: Double(([LatitudeString] as NSString).doubleValue))
var currentLocationLatitude = "45.5626" // your string latitude
var currentLocationLongitude = "45.5626" // your string longitude
var currentLocation:CLLocationCoordinate2D! //location object
currentLocation = CLLocationCoordinate2D(latitude:currentLocationLatitude.toDouble() ?? 0.0, longitude: currentLocationLongitude.toDouble() ?? 0.0)
extension String
{
/// EZSE: Converts String to Double
public func toDouble() -> Double?
{
if let num = NumberFormatter().number(from: self) {
return num.doubleValue
} else {
return nil
}
}
}
You can take string latitude and longitude from you API response and in CLLocationCoordinate2D variable, pass with converting to Double value.
I have also added extension for converting string to double.
might help
let Latitude = ("41" as NSString).doubleValue
let Longitude = ("29" as NSString).doubleValue
Related
I want to retrieve the longitute and latitude using an address as a string. I found this very useful post here: Convert address to coordinates swift
But when I want to save the results in a double field and return it I can't. What I have done is
func getLatitude(address:String) -> Double{
var lati = 0.0
var geocoder = CLGeocoder()
geocoder.geocodeAddressString("your address") {
placemarks, error in
let placemark = placemarks?.first
if let lat = placemark?.location?.coordinate.latitude{
lati = lat
}
}
}
return lati
}
Inside the geocoder.geocodeAddressString block the value is populated but when I try to return it always gives me 0.0 and I have tried everything. Any ideas please?
If it try to print the value inside the inner block of code it gets printed but I can never return it.
Thank you in advance for the answers.
CLLocationCoordinate2D is struct of latitude and longitude both defined as CLLocationDegrees which itself is a typealias of Double.
var latitude: Double?
var longitude: Double?
func getLocation(address: String) {
let geocoder = CLGeocoder()
geocoder.geocodeAddressString(address) { placemarks, error in
guard let placemark = placemarks?.first else { return }
let coordinate = placemark.location?.coordinate
latitude = coordinate?.latitude
longitude = coordinate?.longitude
}
}
My map annotation works well when physically putting the numbers in, but, how do I use it so,
for example, latitudelabel.text is read as the latitude rather than 38.897957?
Here is the code:
func showEmergenyOnMap() {
let emergency = MKPointAnnotation()
emergency.title = "Ongoing Emergency"
emergency.coordinate = CLLocationCoordinate2D(latitude: 38.897957, longitude: -77.036560)
Map.addAnnotation(emergency)
}
Covert string to double.
let lati = Double(label.text)
// do same for longi
Then init coordinate
let coords = CLLocationCoordinate2D(latitude: lati, longitude: longi)
UILabel's text property is an Optional variable so it can have a value or a nil. First of all you need to safely unwrap that value because CLLocationDegrees initializer takes a non-optional String. You can see the below example on how to convert labels text to CLLocationCoordinate2D,
var latitude: CLLocationDegrees = 0.0
var longitude: CLLocationDegrees = 0.0
if let latText = latitudelabel.text, let lat = CLLocationDegrees(latText) {
latitude = lat
}
if let longText = longitudelabel.text, let long = CLLocationDegrees(longText) {
longitude = long
}
let location = CLLocationCoordinate2D(latitude: latitude, longitude: longitude)
I'm trying to save the coordinates of a user while in one ViewController so that it can be used to create an Annotation that can displayed in another ViewController.
In the view controller that stores the coordinates I'm using the code
NSUserDefaults.standardUserDefaults().setObject( Location, forKey: "Location")
In the map view controller that displays the annotation I'm trying to get the coordinates using the code
let Location = NSUserDefaults.standardUserDefaults().stringForKey("Location")
var Annotation = MKPointAnnotation()
Annotation.coordinate = Location
It is telling me that the value of type String? to a value of type CLLocationCoordinate2D.
So how do I convert the CLLocationCoordinate2D coordinates into a value of type String?
This way you can store Locations to NSUserDefaults:
//First Convert it to NSNumber.
let lat : NSNumber = NSNumber(double: Location.latitude)
let lng : NSNumber = NSNumber(double: Location.longitude)
//Store it into Dictionary
let locationDict = ["lat": lat, "lng": lng]
//Store that Dictionary into NSUserDefaults
NSUserDefaults.standardUserDefaults().setObject(locationDict, forKey: "Location")
After that you can access it this way:
//Access that stored Values
let userLoc = NSUserDefaults.standardUserDefaults().objectForKey("Location") as! [String : NSNumber]
//Get user location from that Dictionary
let userLat = userLoc["lat"]
let userLng = userLoc["lng"]
var Annotation = MKPointAnnotation()
Annotation.coordinate.latitude = userLat as! CLLocationDegrees //Convert NSNumber to CLLocationDegrees
Annotation.coordinate.longitude = userLng as! CLLocationDegrees //Convert NSNumber to CLLocationDegrees
UPDATE:
HERE is your Example project.
extension CLLocationCoordinate2D:Printable
{
init(coords : String)
{
var fullNameArr = split(coords) {$0 == ";"}
self.latitude = NSNumberFormatter().numberFromString(fullNameArr[0])!.doubleValue
self.longitude = (fullNameArr.count > 1) ? NSNumberFormatter().numberFromString(fullNameArr[1])!.doubleValue : 0
}
public var description : String
{
return "\(self.latitude);\(self.longitude)"
}
}
Then use as in your sample code :
var coord = CLLocationCoordinate2D(latitude: 3.2, longitude: 6.4)
NSUserDefaults.standardUserDefaults().setObject(coord.description, forKey: "Location")
var readedCoords = CLLocationCoordinate2D(coords: NSUserDefaults.standardUserDefaults().stringForKey("Location")!)
You can store the latitude or the longitude (or both in a dictionary or a tuple). The way to wrap them in String:
func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
var locValue:CLLocationCoordinate2D = manager.location!.coordinate
var lat : String = locValue.latitude.description
var lng : String = locValue.longitude.description
//do whatever you want with lat and lng
}
Using an sprint kind of formatting:
func Coord2String(location : CLLocationCoordinate2D) -> String {
return String(format : "latitude : %f, longitude : %f", location.latitude, location.longitude)
}
I had been struggling to store CLLocationCoordinate2D data from markers on a google maps to CoreData. This cannot be done directly but I found a work around where I take the coordinates, split into CLLocationDegrees, convert it into a string text and store it. I do this by the following:
let marker = GMSMarker()
marker.position = CLLocationCoordinate2DMake(place.coordinate.latitude, place.coordinate.longitude)
let newPlaceLatitude = place.coordinate.latitude
print(newPlaceLatitude)
var latitudeText:String = "\(newPlaceLatitude)"
self.latitudeText = "\(newPlaceLatitude)"
let newPlaceLongitude = place.coordinate.longitude
print(newPlaceLongitude)
var longitudeText:String = "\(newPlaceLongitude)"
self.longitudeText = "\(newPlaceLongitude)"
Storing into CoreData:
let appDelegate = UIApplication.shared.delegate as! AppDelegate
let context = appDelegate.persistentContainer.viewContext
let newPlace = NSEntityDescription.insertNewObject(forEntityName:
"StoredPlace", into: context)
newPlace.setValue(latitudeText, forKeyPath: "latitude")
newPlace.setValue(longitudeText, forKeyPath: "longitude")
However now I am struggling to reconstruct the strings back into CLLocationCoordinates. How would I turn a string to a CLLocationDegree/CLLocationCoordinate2D ? This is supposedly pretty simple but I have found that the following method doesn't work:
let latitude: CLLocationDegrees = Double(latitudeText)!
let longitude: CLLocationDegrees = Double(longitudeText)!
let markers = GMSMarker()
print(latitude)
print(longitude)
markers.position = CLLocationCoordinate2D(latitude: latitude, longitude: longitude)
any other suggestions about how to change string to coordinate?
CLLocation's latitude and longitude are doubles, so with that in mind, you might consider having latitude and longitude properties that are doubles on your StoredPlace object. I called the properties coordinateX and coordinateY so it's easier to remember that they're custom coordinates, not "factory" properties.
You could create an extension in a file called StoredPlace+Extension.swift that looks like this:
import CoreData
import CoreLocation
extension StoredPlace {
func location() -> CLLocation {
let location = CLLocation(latitude: self.coordinateX, longitude: self.coordinateY)
return location
}
}
With this extension, you can then get the coordinates out of your results as follows:
for result in results {
print("coordinate = \(result.location().coordinate)")
print("latitude = \(result.location().coordinate.latitude)")
print("longitude = \(result.location().coordinate.longitude)")
}
You need to typecast your lat and long in decimal values, more preferable is double instead of float because of precision value which can drop pins at perfect locations.
Type casting in double using as keyword:
(yourCordinateString as NSString).doubleValue
casting in float values:
(yourCordinateString as NSString).floatValue
I'm trying to save the coordinates of a user while in one ViewController so that it can be used to create an Annotation that can displayed in another ViewController.
In the view controller that stores the coordinates I'm using the code
NSUserDefaults.standardUserDefaults().setObject( Location, forKey: "Location")
In the map view controller that displays the annotation I'm trying to get the coordinates using the code
let Location = NSUserDefaults.standardUserDefaults().stringForKey("Location")
var Annotation = MKPointAnnotation()
Annotation.coordinate = Location
It is telling me that the value of type String? to a value of type CLLocationCoordinate2D.
So how do I convert the CLLocationCoordinate2D coordinates into a value of type String?
This way you can store Locations to NSUserDefaults:
//First Convert it to NSNumber.
let lat : NSNumber = NSNumber(double: Location.latitude)
let lng : NSNumber = NSNumber(double: Location.longitude)
//Store it into Dictionary
let locationDict = ["lat": lat, "lng": lng]
//Store that Dictionary into NSUserDefaults
NSUserDefaults.standardUserDefaults().setObject(locationDict, forKey: "Location")
After that you can access it this way:
//Access that stored Values
let userLoc = NSUserDefaults.standardUserDefaults().objectForKey("Location") as! [String : NSNumber]
//Get user location from that Dictionary
let userLat = userLoc["lat"]
let userLng = userLoc["lng"]
var Annotation = MKPointAnnotation()
Annotation.coordinate.latitude = userLat as! CLLocationDegrees //Convert NSNumber to CLLocationDegrees
Annotation.coordinate.longitude = userLng as! CLLocationDegrees //Convert NSNumber to CLLocationDegrees
UPDATE:
HERE is your Example project.
extension CLLocationCoordinate2D:Printable
{
init(coords : String)
{
var fullNameArr = split(coords) {$0 == ";"}
self.latitude = NSNumberFormatter().numberFromString(fullNameArr[0])!.doubleValue
self.longitude = (fullNameArr.count > 1) ? NSNumberFormatter().numberFromString(fullNameArr[1])!.doubleValue : 0
}
public var description : String
{
return "\(self.latitude);\(self.longitude)"
}
}
Then use as in your sample code :
var coord = CLLocationCoordinate2D(latitude: 3.2, longitude: 6.4)
NSUserDefaults.standardUserDefaults().setObject(coord.description, forKey: "Location")
var readedCoords = CLLocationCoordinate2D(coords: NSUserDefaults.standardUserDefaults().stringForKey("Location")!)
You can store the latitude or the longitude (or both in a dictionary or a tuple). The way to wrap them in String:
func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
var locValue:CLLocationCoordinate2D = manager.location!.coordinate
var lat : String = locValue.latitude.description
var lng : String = locValue.longitude.description
//do whatever you want with lat and lng
}
Using an sprint kind of formatting:
func Coord2String(location : CLLocationCoordinate2D) -> String {
return String(format : "latitude : %f, longitude : %f", location.latitude, location.longitude)
}