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iOS

Posted by Oliver Pinchbeck
Oliver Pinchbeck
2,732 Points

Converting an Array of Dictionaries

I've been following the Swift Tutorials by Pasan, and found a nice version of my own to work on for the Weather App project.

I'm looking at an API endpoint of car park data, and I think what I'm getting back is an array of dictionaries. I feel like I'm following and translating well from Pasan's demo to my code, but in my latest change I'm making a mistake somewhere. I think I'm converting incorrectly between NSDictionary and NSArray (because Pasan's example uses a dictionary of dictionaries, so I'm not following so directly...

Oliver Pinchbeck
Oliver Pinchbeck
2,732 Points

The code is short enough I'm just going to copy everything for ease of reference:

ViewController.swift

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        let parkingURL: NSURL? = NSURL(string:"https://data.bathhacked.org/resource/u3w2-9yme.json")

        let sharedSession = NSURLSession.sharedSession()
        let downloadTask: NSURLSessionDownloadTask = sharedSession.downloadTaskWithURL(parkingURL!, completionHandler: { (location: NSURL!, response: NSURLResponse!, error: NSError!) -> Void in

            if (error == nil) {
                let dataObject = NSData(contentsOfURL: location)
                let parkingDataArray: NSArray = NSJSONSerialization.JSONObjectWithData(dataObject!, options: nil, error: nil) as NSArray

                let oddDownCPInfo = ParkingData(parkingDataArray: parkingDataArray)
                println(oddDownCPInfo)

// I think what's going wrong here is that I'm downcasting between Dict and Array incorrectly somehow. Could be completely wrong though...


//            println(parkingDataArray)
//                
//                let oddDownCPInfo = parkingDataArray[0] as NSDictionary
//                println(oddDownCPInfo)
//                
//                let landsdownCPArray: NSArray = parkingDataArray[0] as NSArray
////                println(landsdownCPArray)


            } else {
                println("Something went wrong")
            }

        })

        downloadTask.resume()

    }



    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }



}

and ParkingData.swift

struct ParkingData {

    var name: String
    var capacity: Int
    var occupancy: Int
    var percentage: Int
    var status: String
    var lastupdate: String
    var dateuploaded: String
    var description: String
    var northing: Int
    var easting: Int
    var id: String

    init(parkingDataArray: NSArray) {

        let oddDownParkingData = parkingDataArray[0] as NSDictionary

// I think what's going wrong here is that I'm downcasting between Dict and Array incorrectly somehow. Could be completely wrong though...

        name = oddDownParkingData["name"] as String
        capacity = oddDownParkingData["capacity"] as Int
        occupancy = oddDownParkingData["occupancy"] as Int
        percentage = oddDownParkingData["percentage"] as Int
        status = oddDownParkingData["status"] as String
        lastupdate = oddDownParkingData["lastupdate"] as String
        dateuploaded = oddDownParkingData["dateuploaded"] as String
        description = oddDownParkingData["description"] as String
        northing = oddDownParkingData["northing"] as Int
        easting = oddDownParkingData["easting"] as Int
        id = oddDownParkingData["id"] as String
    }

}