Swift - How to save images for the associated map annotation (pin)? - ios

Question

I want to create an object graph of Pins with Images inside of the Pins. I have a class Pin, which stores map annotations (pins). Inside this class, I have an array of images of type Image. My goal is to have each and every pin have it's own set of images based on the coordinate points of that pin. (This is not about Core Data. It is about implementing the Image class below).
Basically, I want to create a Class Image to put the downloaded images there and store it for the selected pin. Once I have the 21 images for the pin, I do not want to re-download new images for that specific pin unless a button is pressed to do so. For example, if a pin is selected for Times Square, New York and I get 21 images of dogs on the street, this will be saved. If I now go back to the map select a different pin and then decide to reselect the same Times Square, New York from before, I should still see the same 21 images of dogs on the street. Only by clicking a button for re-downlaoding will new pictures replace the 21 images of dogs on the street to who knows what is on Flickr for those coordinates.
import Foundation
import UIKit
import MapKit
class Pin: Hashable {
var hashValue: Int {
get {
return "\(latitude.hashValue),\(longitude.hashValue)".hashValue
}
}
let latitude: Double
let longitude: Double
var images = [Image]()
init(latitude: Double, longitude: Double)
{
self.latitude = latitude
self.longitude = longitude
}
}
// must be declared in the global scope! and not just in the class scope
func ==(lhs: Pin, rhs: Pin) -> Bool
{
return lhs.hashValue == rhs.hashValue
}
My Image class is currently empty:
import UIKit
class Image {
}
When a user drops a pin on the map using a long press gesture, this pin is not added to the Set of pins. This happens only when a user selects the pin. See this code:
class MapViewController: UIViewController, MKMapViewDelegate, UIGestureRecognizerDelegate {
var pins = Set<Pin>()
func mapView(mapView: MKMapView!, didSelectAnnotationView view: MKAnnotationView!) {
if editAndDoneButtonText.title == "Edit" {
println("Pin Selected")
/* Get lat/long coordinates of a pin by tapping on the it and update appDelegate variables.
Will use this for networking call to get Flickr images and to populate data structure for storage.
*/
var latFromPin = view.annotation.coordinate.latitude
var latString = String(stringInterpolationSegment: latFromPin)
appDelegate.LAT = latString
var lonFromPin = view.annotation.coordinate.longitude
var lonString = String(stringInterpolationSegment: lonFromPin)
appDelegate.LON = lonString
latCollectionView = latFromPin
lonCollectionView = lonFromPin
// Add pin to set
let selectedCoordinatePoint = Pin(latitude: latFromPin, longitude: lonFromPin)
var select = "\(latFromPin.hashValue),\(lonFromPin.hashValue)".hashValue
pins.insert(selectedCoordinatePoint)
// Goto to next view controller and show data depending on the pin selected
for pin in pins {
if pin.hashValue == select.hashValue {
println("SAME: pin.hashValue: \(pin.hashValue), select.hashValue: \(select.hashValue)")
dispatch_async(dispatch_get_main_queue()) {
let storyBoard = UIStoryboard(name: "Main", bundle: nil)
let secondViewController = self.storyboard!.instantiateViewControllerWithIdentifier("CollectionViewControllerID") as! CollectionViewController
self.navigationController?.pushViewController(secondViewController, animated: true)
}
}
}
}
// Remove pins from map by tapping on it
if editAndDoneButtonText.title == "Done" {
var annotationToRemove = view.annotation
mapView.removeAnnotation(annotationToRemove)
println("remove pin - didSelectAnnotationView")
}
}
When a pin is selected, the app goes to the next view controller. Inside viewWillAppear, a networking call is made to Flickr to download images that are associated with the lat/lon coordinates of the selected pin. These images are used to be displayed in a collection view.
class CollectionViewController: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource, MKMapViewDelegate {
let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
var arrayOfImages: [UIImage] = [] // Array from Flickr
var pin: Pin!
override func viewWillAppear(animated: Bool) {
// Flickr
// 2 - API Method Arguments
let methodArguments = [
"method": appDelegate.METHOD_NAME,
"api_key": appDelegate.API_KEY,
"extras": appDelegate.EXTRAS,
"lat": appDelegate.LAT,
"lon": appDelegate.LON,
"format": appDelegate.DATA_FORMAT,
"nojsoncallback": appDelegate.NO_JSON_CALLBACK
]
// 3 - Initialize session and url
let session = NSURLSession.sharedSession()
let urlString = appDelegate.BASE_URL + appDelegate.escapedParameters(methodArguments)
let url = NSURL(string: urlString)!
let request = NSURLRequest(URL: url)
// 4 - Initialize task for getting data
let task = session.dataTaskWithRequest(request) { data, response, downloadError in
if let error = downloadError {
println("Could not complete the request \(error)")
} else {
// 5 - Success! Parse the data
var parsingError: NSError? = nil
let parsedResult: AnyObject! = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.AllowFragments, error: &parsingError) as! NSDictionary
// println("parsedResult = \(parsedResult)")
if let photosDictionary = parsedResult.valueForKey("photos") as? [String:AnyObject] {
// println("photosDictionary = \(photosDictionary)")
if let photosArray = photosDictionary["photo"] as? [[String:AnyObject]] {
// println("photosArray = \(photosArray )")
var count = 0
for photo in photosArray {
// 6 - Grab 21 random images
if count <= 20 {
// Grabs 1 image
let randomPhotoIndex = Int(arc4random_uniform(UInt32(photosArray.count)))
let photoDictionary = photosArray[randomPhotoIndex] as [String:AnyObject]
// 7 - Get the image url
let imageUrlString = photoDictionary["url_m"] as? String
let imageURL = NSURL(string: imageUrlString!)
// 8 - If an image exists at the url, append to array
let imageData = NSData(contentsOfURL: imageURL!)
let finalImage = UIImage(data: imageData!)
self.arrayOfImages.append(finalImage!) // Append to array outside of this closure
count += 1
println(self.arrayOfImages.count)
}
}
dispatch_async(dispatch_get_main_queue()) {
self.collectionView.reloadData()
}
}
}
}
}
// 6 - Resume (execute) the task
task.resume()
}
// Collection view......
}
Currently I am using an array called var arrayOfImages: [UIImage] = []. The networking call downloads 21 images (if available) from Flickr for each pin and stores it in this array.
I've been able to store the pins. Can anyone help with this?

Answer 1

Not sure what the question is... but seems like you're storing a collection of Images correctly. All that's left is to implement the Image class. You can create a property within it called photo that has the class UIImage then instantiate those in your network call. Is that what you were looking for?