Download and cache the MKMapSnapshotter image using SDWebimage - swift

Question

I want to show mapView in UITableViewCells,
So I actually wrote this code
class DataPointTableCell: UITableViewCell {
#IBOutlet weak var mapView: MKMapView!
func addAnnotaionToMapView(_ coordinates: Coordinate) {
removePreviousCoordinate()
let viewCoorindate = CLLocationCoordinate2D(latitude: coordinates.latitude, longitude: coordinates.longitude)
let annotation = MKPointAnnotation()
annotation.coordinate = viewCoorindate
mapView.addAnnotation(annotation)
// animate is turned to false on purpose.
mapView.animateToPoint(viewCoorindate, animated: false)
}
private func removePreviousCoordinate() {
let annotations = self.mapView.annotations
self.mapView.removeAnnotations(annotations)
}
}
The problem with this approach is that it animates the mapView location and then adds the marker as it deques the cell.
I went with another approach i.e. by using MKMapSnapshotter
private func setMapImage() {
let rect = self.mapImageView.bounds
let mapSnapshotOptions = MKMapSnapshotter.Options()
// Set the region of the map that is rendered.
let needleLocation = CLLocationCoordinate2DMake(15.4952364, 73.8343293)
let region = MKCoordinateRegion(center: needleLocation, latitudinalMeters: 1000, longitudinalMeters: 1000)
mapSnapshotOptions.region = region
// Set the scale of the image. We'll just use the scale of the current device, which is 2x scale on Retina screens.
mapSnapshotOptions.scale = UIScreen.main.scale
// Set the size of the image output.
mapSnapshotOptions.size = CGSize(width: 300, height: 300)
// Show buildings and Points of Interest on the snapshot
mapSnapshotOptions.showsBuildings = true
mapSnapshotOptions.showsPointsOfInterest = false
let snapshot = MKMapSnapshotter(options: mapSnapshotOptions)
snapshot.start { snapshot, error in
guard let snapshot = snapshot, error == nil else {
print("\(error!.localizedDescription)")
return
}
UIGraphicsBeginImageContextWithOptions(mapSnapshotOptions.size, true, 0)
snapshot.image.draw(at: .zero)
let pinView = MKPinAnnotationView(annotation: nil, reuseIdentifier: nil)
let pinImage = pinView.image
var point = snapshot.point(for: needleLocation)
if rect.contains(point) {
let pinCenterOffset = pinView.centerOffset
point.x -= pinView.bounds.size.width / 2
point.y -= pinView.bounds.size.height / 2
point.x += pinCenterOffset.x
point.y += pinCenterOffset.y
pinImage?.draw(at: point)
}
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
DispatchQueue.main.async {
self.mapImageView.image = image
}
}
}
This works fine but I can't cache image based on anything.
So the help that I wanted is how to download and cache the mapImage using SDWebimage.

Answer 1

First add a unique key for your cell
var youUniqueCellKey = "Key"
Then in setMapImage first check if an image is already Cached or not and assign it to your mapImageView
private func setMapImage() {
if let image = SDImageCache.shared().imageFromCache(forKey: youUniqueCellKey) {
self.mapImageView.image = image
} else {
// Add your rest of your code here
// At the end
var imageToStore = UIImage() // Your mapImage
SDImageCache.shared().store(imageToStore, forKey: youUniqueCellKey, completion: nil)
}
}