I have a class named Location that has several methods in it that do not have any parameters.
However, when I try to create a variable with the result of the method, it wants an argument. Why is that?
Location class:
let locationManager = CLLocationManager()
public class Location {
public func coordinate() -> (latitude: Float?, longitude: Float?) {
let latitude = Float((locationManager.location?.coordinate.latitude)!)
let longitude = Float((locationManager.location?.coordinate.longitude)!)
return (latitude: latitude, longitude: longitude)
}
public func getCity() -> String {
var returnCity: String = "N/A"
let geoCoder = CLGeocoder()
let location = CLLocation(latitude: (locationManager.location?.coordinate.latitude)!, longitude: (locationManager.location?.coordinate.longitude)!)
geoCoder.reverseGeocodeLocation(location, completionHandler: { (placemarks, error) -> Void in
// Place details
var placeMark: CLPlacemark!
placeMark = placemarks?[0]
// City
if let city = placeMark.addressDictionary!["City"] as? String {
returnCity = city
}
})
return returnCity
}
public func getCountry() -> String {
var returnCountry: String = "N/A"
let geoCoder = CLGeocoder()
let location = CLLocation(latitude: (locationManager.location?.coordinate.latitude)!, longitude: (locationManager.location?.coordinate.longitude)!)
geoCoder.reverseGeocodeLocation(location, completionHandler: { (placemarks, error) -> Void in
// Place details
var placeMark: CLPlacemark!
placeMark = placemarks?[0]
// City
if let country = placeMark.addressDictionary!["Country"] as? String {
returnCountry = country
}
})
return returnCountry
}
public func getZip() -> Int {
var returnZip: Int = 0
let geoCoder = CLGeocoder()
let location = CLLocation(latitude: (locationManager.location?.coordinate.latitude)!, longitude: (locationManager.location?.coordinate.longitude)!)
geoCoder.reverseGeocodeLocation(location, completionHandler: { (placemarks, error) -> Void in
// Place details
var placeMark: CLPlacemark!
placeMark = placemarks?[0]
// City
if let zip = placeMark.addressDictionary!["ZIP"] as? Int {
returnZip = zip
}
})
return returnZip
}
public func getLocationName() -> String {
var returnName: String = "N/A"
let geoCoder = CLGeocoder()
let location = CLLocation(latitude: (locationManager.location?.coordinate.latitude)!, longitude: (locationManager.location?.coordinate.longitude)!)
geoCoder.reverseGeocodeLocation(location, completionHandler: { (placemarks, error) -> Void in
// Place details
var placeMark: CLPlacemark!
placeMark = placemarks?[0]
// City
if let locationName = placeMark.addressDictionary!["Name"] as? String {
returnName = locationName
}
})
return returnName
}
public func getStreetAddress() -> String {
var returnAddress: String = "N/A"
let geoCoder = CLGeocoder()
let location = CLLocation(latitude: (locationManager.location?.coordinate.latitude)!, longitude: (locationManager.location?.coordinate.longitude)!)
geoCoder.reverseGeocodeLocation(location, completionHandler: { (placemarks, error) -> Void in
// Place details
var placeMark: CLPlacemark!
placeMark = placemarks?[0]
// City
if let street = placeMark.addressDictionary!["Thoroughfare"] as? String {
returnAddress = street
}
})
return returnAddress
}
}
Trying to create a variable:
let city = Location.getCity()
Here are some screen shots of what I get:
These methods are not class methods, they are instance methods. You must call them on an instance of the Location class, not on the class itself. Evidently, Swift can call instance methods similarly to Python: the method is a function owned by the class, and its argument is an instance of the class. But you should not call instance methods this way.
The best way to solve this problem is to construct a Location object and then call the method on it:
let city: Location = Location().getCity()
Because you're trying to call it as a class function. You should be creating an instance of Location and calling the function on that. Note also that it returns String Where your code is telling the compiler you're expecting it to return a Location.
Related
I am having trouble with working over data I receive from server.
Each time server sends data it is new coordinates for each user. I am looping over each incoming data, and I want to send the data in completion to receive them on other end. And update model class with them. At the moment I have two users in server. And sometimes the closure passes data two times, but sometimes just one. And interesting thing is that class properties are not updated, at least I dont see them on UI.
This is function I call when data is received. Response is just string I split to get user data.
func updateUserAdrress(response: String, completion: #escaping (Int, Double, Double, String) -> Void){
var data = response.components(separatedBy: "\n")
data.removeLast()
data.forEach { part in
let components = part.components(separatedBy: ",")
let userID = components[0].components(separatedBy: " ")
let id = Int(userID[1])
let latitude = Double(components[1])!
let longitude = Double(components[2])!
let location = CLLocation(latitude: latitude, longitude: longitude)
let geocoder = CLGeocoder()
geocoder.reverseGeocodeLocation(location) { (placemarks, error) in
if error == nil {
let placemark = placemarks?[0]
if let thoroughfare = placemark?.thoroughfare, let subThoroughfare = placemark?.subThoroughfare {
let collectedAddress = thoroughfare + " " + subThoroughfare
DispatchQueue.main.async {
completion(id!, latitude, longitude, collectedAddress)
}
}
} else {
print("Could not get address \(error!.localizedDescription)")
}
}
}
}
In this function I try to invoke the changes on objects. As the incoming data from server is different the first time I have splited the functionality, so the correct block of code would be called.
func collectUsers(_ response: String){
if users.count != 0{
updateUserAdrress(response: response) { id, latitude, longitude, address in
if let index = self.users.firstIndex(where: { $0.id == id }){
let user = self.users[index]
user.latitude = latitude
user.longitude = longitude
user.address = address
}
}
}else{
var userData = response.components(separatedBy: ";")
userData.removeLast()
let users = userData.compactMap { userString -> User? in
let userProperties = userString.components(separatedBy: ",")
var idPart = userProperties[0].components(separatedBy: " ")
if idPart.count == 2{
idPart.removeFirst()
}
guard userProperties.count == 5 else { return nil }
guard let id = Int(idPart[0]),
let latitude = Double(userProperties[3]),
let longitude = Double(userProperties[4]) else { return nil }
let collectedUser = User(id: id, name: userProperties[1], image: userProperties[2], latitude: latitude, longitude: longitude)
return collectedUser
}
DispatchQueue.main.async {
self.users = users
}
}
}
As I also need user address when app starts in model I have made simular function to call in init so it would get address for user. That seems to be working fine. But for more context I will add the model to.
class User: Identifiable {
var id: Int
let name: String
let image: String
var latitude: Double
var longitude: Double
var address: String = ""
init(id: Int, name: String, image: String, latitude: Double, longitude: Double){
self.id = id
self.name = name
self.image = image
self.latitude = latitude
self.longitude = longitude
getAddress(latitude: latitude, longitude: longitude) { address in
self.address = address
}
}
func getAddress(latitude: Double, longitude: Double, completion: #escaping (String) -> Void){
let location = CLLocation(latitude: latitude, longitude: longitude)
let geocoder = CLGeocoder()
geocoder.reverseGeocodeLocation(location) { (placemarks, error) in
if error == nil {
let placemark = placemarks?[0]
if let thoroughfare = placemark?.thoroughfare, let subThoroughfare = placemark?.subThoroughfare {
let collectedAddress = thoroughfare + " " + subThoroughfare
completion(collectedAddress)
}
} else {
print("Could not get address \(error!.localizedDescription)")
}
}
}
}
And one interesting thing. That when closure receives two times data and I assign them to class, there are no changes on UI.
I made this project on Xcode 13.4.1 because on Xcode 14 there is a bug on MapAnnotations throwing purple warnings on view changes.
Trying to get name of a city, while having latitude and longitude.
Inside a model class Location, I'm using reverseGeocodeLocation(location: , completionHandler: ) func that comes with CLGeocoder (part of CoreLocation).
func getLocationName() {
let geoCoder = CLGeocoder()
let location = CLLocation(latitude: currentLatitude, longitude: currentLongitude)
geoCoder.reverseGeocodeLocation(location, completionHandler: { placemarks, error in
guard let addressDict = placemarks?[0].addressDictionary else {
return
}
if let city = addressDict["City"] as? String {
self.currentCity = city
print(city)
}
if let zip = addressDict["ZIP"] as? String {
print(zip)
}
if let country = addressDict["Country"] as? String {
print(country)
}
})
}
However, in ViewController, after running the getLocationName(), the location.currentCity is nil, since the completion handler is async, and wasn't finished yet.
How can I make sure that the completion handler is finished running so I can access location.currentCity ?
Pass a closure as a function parameter in your getLocationName which
you can call inside the reverseGeocodeLocation closure.
func updateLocation(currentCity : String) -> Void
{
print(currentCity)
}
func getLocationName(callback : #escaping (String) -> Void)
{
let geoCoder = CLGeocoder()
let location = CLLocation(latitude: currentLatitude, longitude: currentLongitude)
geoCoder.reverseGeocodeLocation(location, completionHandler: { placemarks, error in
guard let addressDict = placemarks?[0].addressDictionary else {
return
}
if let city = addressDict["City"] as? String
{
self.currentCity = city
callback(city)
print(city)
}
if let zip = addressDict["ZIP"] as? String {
print(zip)
}
if let country = addressDict["Country"] as? String {
print(country)
}
})
}
In your ViewController...
getLocationName(callback: updateLocation)
I would create a function where location.currentCity is used, and call this function from the completion handler
So if your code looks like:
func foo() {
var location
getLocationName()
print(location.currentcity) // nil
}
change it to:
func foo() {
var location
getLocationName()
}
func bar() {
print(location.currentcity) // someplace
}
and call bar() from your completion handler
I am trying to figure out how to reverse geocode a CLLocation stored in CloudKit. I have the location stored in a record and I know it stores as latitude and longitude. Here's my record. The latitude and longitude appear I just took them out for now.
However I want to be able to make the location user-readable, so AKA reverse geocode it, to get the city and state. And I've looked on here so far but nothing on reverse geocoding the location I can store in CloudKit.
Here is my model:
class Peek: CloudKitSyncable {
static let kType = "Peek"
static let kPhotoData = "photoData"
static let kTimeStamp = "timestamp"
static let kTitle = "title"
static let kText = "text"
static let kLocation = "location"
static let kCity = "city"
let title: String
let text: String
let photoData: Data?
let timestamp: Date
var location: CLLocation
var comments: [Comment]
var photo: UIImage? {
guard let photoData = self.photoData else { return nil }
return UIImage(data: photoData)
}
init(title: String, timestamp: Date = Date(), text: String, photoData: Data?, comments: [Comment] = [], location: CLLocation) {
self.title = title
self.timestamp = timestamp
self.text = text
self.photoData = photoData
self.comments = comments
self.location = location
}
var recordType: String {
return Peek.kType
}
var cloudKitRecordID: CKRecordID?
convenience required init?(record: CKRecord) {
guard let timestamp = record.creationDate,
let photoAsset = record[Peek.kPhotoData] as? CKAsset,
let title = record[Peek.kTitle] as? String,
let text = record[Peek.kText] as? String,
let location = record[Peek.kLocation] as? CLLocation else { return nil }
let photoData = try? Data(contentsOf: photoAsset.fileURL)
self.init(title: title, timestamp: timestamp, text: text, photoData: photoData, location: location)
cloudKitRecordID = record.recordID
}
fileprivate var temporaryPhotoURL: URL {
let temporaryDirectory = NSTemporaryDirectory()
let temporaryDirectoryURL = URL(fileURLWithPath: temporaryDirectory)
let fileURL = temporaryDirectoryURL.appendingPathComponent(UUID().uuidString).appendingPathExtension("jpg")
try? photoData?.write(to: fileURL, options: .atomic)
return fileURL
}
}
extension CKRecord {
convenience init(_ peek: Peek) {
let recordID = CKRecordID(recordName: UUID().uuidString)
self.init(recordType: peek.recordType, recordID: recordID)
self[Peek.kTitle] = peek.title as String? as CKRecordValue?
self[Peek.kText] = peek.text as String? as CKRecordValue?
self[Peek.kTimeStamp] = peek.timestamp as CKRecordValue?
self[Peek.kLocation] = peek.location as CKRecordValue?
self[Peek.kPhotoData] = CKAsset(fileURL: peek.temporaryPhotoURL)
}
}
I also have a LocationManager file as well:
class LocationManager: NSObject {
static let sharedInstance = LocationManager()
override init() {
super.init()
locationManager.delegate = self
}
var locationManager = CLLocationManager()
var currentLocation: CLLocation?
func requestCurrentLocation() {
locationManager.requestLocation()
}
}
extension LocationManager: CLLocationManagerDelegate {
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
currentLocation = locations.first
}
func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
print("error: \(error.localizedDescription)")
}
func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
if status == .authorizedWhenInUse {
locationManager.requestLocation()
}
}
}
Apple provides a method built into Core Location's CLGeocoder class. Here are the docs. If successful the completion handler will give you access to an array of CLPlacemark, so you can grab one of those and access whichever human-readable elements you need. The names of the variables are pretty generic to cover locations all over the world, so you'll have to dig in a bit to find exactly what you need. Check the docs on CLPlacemark for exact details on the variables available to you. In your particular case you'll need locality and administrativeArea for city and state, respectively.
Usage would be something like this:
let geocoder = CLGeocoder()
geocoder.reverseGeocodeLocation(location) { (placemarks, error) in
guard let placemarks = placemarks, let placemark = placemarks.first else { return }
if let city = placemark.locality, let state = placemark.administrativeArea {
//Set your labels or whatever
}
}
In a model's class Location, I get the name of the current city:
var currentLatitude: Double!
var currentLongitude: Double!
var currentLocation: String!
var currentCity: String!
func getLocationName() {
let geoCoder = CLGeocoder()
let location = CLLocation(latitude: currentLatitude, longitude: currentLongitude)
geoCoder.reverseGeocodeLocation(location, completionHandler: { placemarks, error in
guard let addressDict = placemarks?[0].addressDictionary else {
return
}
if let city = addressDict["City"] as? String {
self.currentCity = city
print(city)
}
if let zip = addressDict["ZIP"] as? String {
print(zip)
}
if let country = addressDict["Country"] as? String {
print(country)
}
self.nowUpdateUI()
})
}
In view controller I want to update the UI and update my label to show the current city.
However, self.currentCity = city happens inside of a closure. So if I just run a func in view controller:
func updateUI() {
cityLbl.text = Location.sharedInstance.currentCity
}
I'm not getting anywhere because the closure haven't finished running.
I've been advised to add a completion handler to getLocationName() and inside of it, perform the call to a func that will update the UI.
However, from all the tutorials out there on closures, completion handlers, it is not clear to me how to achieve that.
How to construct a completion handler, pass it as an arg to getLocationName() and how to call getLocationName from view controller?
To handle this situation you have multiple option.
Create delegate/protocol with your Location class
Create one protocol and implement that protocol method with your ViewController and declare its instance in your Location class. After then in the completionHandler of reverseGeocodeLocation call this delegate method. Check Apple documentation on Protocol for more details.
You can create completionHandler with your getLocationName method of Location class.
Add completionHandler with getLocationName and called that completionHandler inside the completionHandler of reverseGeocodeLocation like this way.
func getLocationName(completionHandler: #escaping (_ success: Bool) -> Void) {
let geoCoder = CLGeocoder()
let location = CLLocation(latitude: currentLatitude, longitude: currentLongitude)
geoCoder.reverseGeocodeLocation(location, completionHandler: { placemarks, error in
guard let addressDict = placemarks?[0].addressDictionary else {
completionHandler(false)
return
}
if let city = addressDict["City"] as? String {
self.currentCity = city
print(city)
}
if let zip = addressDict["ZIP"] as? String {
print(zip)
}
if let country = addressDict["Country"] as? String {
print(country)
}
completionHandler(true)
//self.nowUpdateUI()
})
}
Now in ViewController where you are calling this function call your updateUI method inside the completion block.
Location.sharedInstance.getLocationName { (success) in
if success {//If successfully got response
self.updateUI()
}
}
You can add observer for (NS)NotificationCenter.
Register the observer with (NS)NotificationCenter and then post the notification inside the completionHandler of reverseGeocodeLocation. You can get more detail on this with this StackOverflow Post.
// I thing issue back ground thread you need to update your UI in main thread
var currentLatitude: Double!
var currentLongitude: Double!
var currentLocation: String!
var currentCity: String!
func getLocationName() {
let geoCoder = CLGeocoder()
let location = CLLocation(latitude: currentLatitude, longitude: currentLongitude)
geoCoder.reverseGeocodeLocation(location, completionHandler: { placemarks, error in
guard let addressDict = placemarks?[0].addressDictionary else {
return
}
if let city = addressDict["City"] as? String {
self.currentCity = city
print(city)
}
if let zip = addressDict["ZIP"] as? String {
print(zip)
}
if let country = addressDict["Country"] as? String {
print(country)
}
DispatchQueue.main.async {
self.nowUpdateUI()
// Update your UI in main thread
}
})
}
This entire piece of your code:
completionHandler: { placemarks, error in
guard let addressDict = placemarks?[0].addressDictionary else {
return
}
if let city = addressDict["City"] as? String {
self.currentCity = city
print(city)
}
if let zip = addressDict["ZIP"] as? String {
print(zip)
}
if let country = addressDict["Country"] as? String {
print(country)
}
self.nowUpdateUI()
}
)
is already happening in the completionHandler (which happens after everything is finished) Just also run your updateUI() inside the completionHandler. So your end code would be :
completionHandler: { placemarks, error in
guard let addressDict = placemarks?[0].addressDictionary else {
return
}
if let city = addressDict["City"] as? String {
self.currentCity = city
DispatchQueue.main.async {
updateUI()
}
}
if let zip = addressDict["ZIP"] as? String {
print(zip)
}
if let country = addressDict["Country"] as? String {
print(country)
}
self.nowUpdateUI()
}
)
The reason you have to use DispatchQueue.main is because your completionHandler is on a backgroundqueue but you MUST always do you UI related stuff from your mainQueue—so users get the fastest changing in their UI without any glitches. Imagine if you were doing on a background thread and it was happening slow
When I pass an address string into CLGeocoder.geocodeAddressString(), the function never executes. When debugging, it never enters geocodeAddressString() and instead skips over. location1 does contain a valid address.
func routeToLocation(location1: String, location2: String) {
var location1Parsed = CLLocation()
var location2Parsed = CLLocation()
let geocoder = CLGeocoder()
geocoder.geocodeAddressString(location1, completionHandler: {(placemarks, error) -> Void in
if ((error) != nil) {
print("Error")
}
if let placemark = placemarks?.first{
let coordinates: CLLocationCoordinate2D = placemark.location!.coordinate
location1Parsed = CLLocation(latitude: coordinates.latitude, longitude: coordinates.longitude)
print(location1Parsed.coordinate.latitude)
print(location1Parsed.coordinate.longitude)
}
})
...
}
Does anyone know why this might be happening?
Thanks