PhotoDownloadManager.swift

//
//  PhotoDownloadManager.swift
//  XebiaSki
//
//  Created by Simone Civetta on 11/11/14.
//  Copyright (c) 2014 Xebia IT Architechts. All rights reserved.
//

import UIKit

public typealias RetrieveCallback = (UIImage?) -> ()
public typealias DownloadCallback = (NSURL?) -> ()

public class PhotoDownloadManager {

    private var photoURL: NSURL
    
    public init(photoURL: NSURL) {
        self.photoURL = photoURL
    }
    
    // MARK: Entry point
    
    public func retrievePhoto(callback: RetrieveCallback) {
        downloadPhoto(self.photoURL, result: {[weak self] (URL) -> () in
            if self == nil {
                callback(nil)
                return;
            }
            if let tempURL = URL? {
                self?.retrievePhotoFromLocalURL(tempURL, callback: callback)
                return;
            }
            callback(nil)
        })
    }
    
    private func retrievePhotoFromLocalURL(URL: NSURL, callback: RetrieveCallback) {
        var photo: UIImage?
        if let photoData = NSData(contentsOfURL: URL)? {
            photo = UIImage(data: photoData)
        }
        
        dispatch_async(dispatch_get_main_queue(), { () -> Void in
            callback(photo)
        })
    }
    
    private func downloadPhoto(URL: NSURL, result: DownloadCallback) {
        let session = NSURLSession.sharedSession()
        session.downloadTaskWithURL(URL, completionHandler: { (localURL: NSURL!, response: NSURLResponse!, error: NSError!) -> Void in
            if let HTTPResponse = response as? NSHTTPURLResponse {
                if HTTPResponse.statusCode == 200 {
                    result(localURL)
                    return;
                }
            }
            result(nil)
        }).resume()
    }
}

SkiResort.swift

//
//  SkiResort.swift
//  XebiaSki
//
//  Created by JC on 30/11/14.
//  Copyright (c) 2014 Xebia IT Architechts. All rights reserved.
//

public class SkiResort: NSObject, NSCoding {
    public var name: String
    public var photoURL: NSURL
    public var temperature: Int
    
    public init(name: String, photoURL: NSURL, temperature: Int) {
        self.name = name
        self.photoURL = photoURL
        self.temperature = temperature
    }
    
    public required init(coder aDecoder: NSCoder) {
        self.name = aDecoder.decodeObjectForKey("name") as String
        self.photoURL = NSURL(string: aDecoder.decodeObjectForKey("photoURL") as String)!
        self.temperature = aDecoder.decodeObjectForKey("temperature") as Int
    }
    
    public func encodeWithCoder(aCoder: NSCoder) {
        aCoder.encodeObject(self.name, forKey: "name")
        aCoder.encodeObject(self.photoURL.absoluteString, forKey: "photoURL")
        aCoder.encodeObject(self.temperature, forKey: "temperature")
    }
}

SkiResortDataSource.swift

//
//  SkiResortDataSource.swift
//  XebiaSki
//
//  Created by Simone Civetta on 02/12/14.
//  Copyright (c) 2014 Xebia IT Architechts. All rights reserved.
//

public class SkiResortDataSource {
    var allObjects: Array<SkiResort>
    
    public init() {
        self.allObjects = [
            SkiResort(name: "Arcabulle", photoURL: NSURL(string: "http://www.trinum.com/ibox/ftpcam/les-arcs_arcabulle.jpg")!, temperature: 5),
            SkiResort(name: "Arcs 1600 Pistes", photoURL: NSURL(string: "http://static1.lesarcsnet.com/image_uploader/webcam/large/lesarcs-1600-cam.jpg")!, temperature: -2),
            SkiResort(name: "Vanoise Express", photoURL: NSURL(string: "http://trinum.com/ibox/ftpcam/Peisey-Vallandry_vanoise-expresse.jpg")!, temperature: 4),
            SkiResort(name: "Arc 1950 Village", photoURL: NSURL(string: "http://www.trinum.com/ibox/ftpcam/arc-1950-haut-village.jpg")!, temperature: 0)
        ]
    }

    public var count: Int {
        get {
            return self.allObjects.count
        }
    }
    
    public subscript(index: Int) -> SkiResort {
        return self.allObjects[index]
    }
}