How to save MKPolyline attribute as converted to iOS coredata with fast?

Question

What will be the code needed to quickly store MKPolyline in CoreData in swift.

So, for example, if I had one of my main data objects (for example, "myEntity") for which I wanted to save MKPolyline, and added the "polyline" field as transformable and set it to "transformable" in Xcode. A subclass of NSManagedObject has also been created.

myEntity.swift

import UIKit import CoreData import MapKit class myEntity: NSManagedObject { } 

MyEntity + CoreDataProperties.swift

 import Foundation import CoreData extension myEntity { @NSManaged var title: String @NSManaged var polyline: NSObject? } 

Question. What code is needed to let this work?

(I mark this message re objective-c, however I'm struggling to figure / port / make it work - How to store data from NSMutable Array in Core Data? )

Answer 1

Archive the polyline object and save the Basic data :

  let context = self.fetchedResultsController.managedObjectContext let entity = self.fetchedResultsController.fetchRequest.entity! let newManagedObject = NSEntityDescription.insertNewObjectForEntityForName(entity.name!, inManagedObjectContext: context) let polylineObj = polyline() // For test purpose. let polylineData = polylineToArchive(polylineObj) newManagedObject.setValue(polylineData, forKey: "polyline") context.save() 

Destroying polyline from NSManagedObject :

  let object = self.fetchedResultsController.objectAtIndexPath(indexPath) as! NSManagedObject let data = object.valueForKey("polyline") as! NSData let polyline = polylineUnarchive(data) log(polyline!) 

MKPolyline arhiver and unarchiver functions. Also some helper functions.

 func polylineUnarchive(polylineArchive: NSData) -> MKPolyline? { guard let data = NSKeyedUnarchiver.unarchiveObjectWithData(polylineArchive), let polyline = data as? [Dictionary<String, AnyObject>] else { return nil } var locations: [CLLocation] = [] for item in polyline { if let latitude = item["latitude"]?.doubleValue, let longitude = item["longitude"]?.doubleValue { let location = CLLocation(latitude: latitude, longitude: longitude) locations.append(location) } } var coordinates = locations.map({(location: CLLocation) -> CLLocationCoordinate2D in return location.coordinate}) let result = MKPolyline(coordinates: &coordinates, count: locations.count) return result } func polylineToArchive(polyline: MKPolyline) -> NSData { let coordsPointer = UnsafeMutablePointer<CLLocationCoordinate2D>.alloc(polyline.pointCount) polyline.getCoordinates(coordsPointer, range: NSMakeRange(0, polyline.pointCount)) var coords: [Dictionary<String, AnyObject>] = [] for i in 0..<polyline.pointCount { let latitude = NSNumber(double: coordsPointer[i].latitude) let longitude = NSNumber(double: coordsPointer[i].longitude) let coord = ["latitude" : latitude, "longitude" : longitude] coords.append(coord) } let polylineData = NSKeyedArchiver.archivedDataWithRootObject(coords) return polylineData } func polyline() -> MKPolyline { let locations = [CLLocation(latitude: 37.582691, longitude: 127.011186), CLLocation(latitude: 37.586112,longitude: 127.011047), CLLocation(latitude: 37.588212, longitude: 127.010438)] var coordinates = locations.map({(location: CLLocation) -> CLLocationCoordinate2D in return location.coordinate}) let polyline = MKPolyline(coordinates: &coordinates, count: locations.count) return polyline } func log(polyline: MKPolyline) { let coordsPointer = UnsafeMutablePointer<CLLocationCoordinate2D>.alloc(polyline.pointCount) polyline.getCoordinates(coordsPointer, range: NSMakeRange(0, polyline.pointCount)) var coords: [Dictionary<String, AnyObject>] = [] for i in 0..<polyline.pointCount { let latitude = NSNumber(double: coordsPointer[i].latitude) let longitude = NSNumber(double: coordsPointer[i].longitude) let coord = ["latitude" : latitude, "longitude" : longitude] coords.append(coord) } print(coords) }