Playlist Browser with Swift

Question

I have completed the 'Build a Playlist Browser with Swift' course and my app functioned up until the last step or so. The problem started when I created all the playlistImageView variables and tried to append them to my playlistArray.

Here is my Playlist code: import Foundation import UIKit

struct Playlist {

var title: String
var description: String
var icon: UIImage
var largeIcon: UIImage
  var artists = [String]()
var backgroundColor: UIColor = UIColor.clearColor()

init(index: Int)    {
    let musicLibrary = MusicLibrary().library
    let playlistDictionary = musicLibrary[index]

    title = (playlistDictionary["title"] as! String)
    description = (playlistDictionary["description"] as! String)

    artists += playlistDictionary["artists"] as! [String]

    let largeIconName = playlistDictionary["largeIcon"] as! String
    largeIcon = UIImage(named: largeIconName)!

    let iconName = playlistDictionary["icon"] as! String
    icon = UIImage(named: iconName)!


    let colorsDictionary = playlistDictionary["backgroundColor"] as! [String: CGFloat]

// backgroundColor = rgbColorFromDictionary(colorsDictionary) // print(colorsDictionary) backgroundColor = UIColor(red: 255/255.0, green: 102/255.0, blue: 51/255.0, alpha: 1.0)

}

func rgbColorFromDictionary(colorDictionary: [String: CGFloat]) -> UIColor {
    let red = colorDictionary["red"]!
     let green = colorDictionary["green"]!
     let blue = colorDictionary["blue"]!
     let alpha = colorDictionary["alpha"]!

    return UIColor(red: red/255.0, green: green/255.0, blue: blue/255.0, alpha: alpha)
}

Here is my Master View Controller code:

import UIKit

class PlaylistMasterViewController: UIViewController {

var playlistArray: [UIImageView!] = []

@IBOutlet weak var playlistImageView0: UIImageView!
@IBOutlet weak var playlistImageView1: UIImageView!
@IBOutlet weak var playlistImageView2: UIImageView!
@IBOutlet weak var playlistImageView3: UIImageView!
@IBOutlet weak var playlistImageView4: UIImageView!
@IBOutlet weak var playlistImageView5: UIImageView!

override func viewDidLoad() {
    super.viewDidLoad()
    playlistArray += [playlistImageView0, playlistImageView1, playlistImageView2, playlistImageView3, playlistImageView4, playlistImageView5]


   for theIndex in 0..<playlistArray.count {

       let playlist = Playlist(index: theIndex)

   let playlistImageView = playlistArray[theIndex]

       playlistImageView.image = playlist.icon
        playlistImageView.backgroundColor = playlist.backgroundColor

    }
}

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

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?)  {
    if segue.identifier == "showPlaylistDetailSegue" {
        let playlistImageView = sender!.view as! UIImageView
         var index = playlistArray.indexOf(playlistImageView)
        let playlistDetailController = segue.destinationViewController as! PlaylistDetailViewController
        }
    }

} @IBAction func showPlaylistDetail(sender: AnyObject) { performSegueWithIdentifier("showPlaylistDetailSegue", sender: sender)

}

I get the following error:

'Cannot convert value if type ‘UIImageView’ to expected argument type @noescape (UIUmageView!) throws -> Bool' and it appears in my Playlist file when I try and declare var index = playlistArray.indexOf(playlistImageView).

Please let me know your thoughts. Thanks!

Answer 1 · 2015-12-15T05:45:35Z

December 15, 2015 5:45am

Hi Robert,

The indexOf method expects a closure. That closure takes an element of the array's type and returns a bool.

Here is an example:

let numbers: [Int] = [ 1, 2, 3, 4, 5, 6]

let index = numbers.indexOf {
    $0 == 3
}

So I think if you update your code and use a closure it might work

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?)  {
    if segue.identifier == "showPlaylistDetailSegue" {
        let playlistImageView = sender!.view as! UIImageView
         var index = playlistArray.indexOf {
             $0 == playlistImageView
           }

Hope that helps,

Mike

PS: Thanks to the awesome resources on Team Treehouse, I just launched my first app. :-)

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Robert Cathlina

Robert Cathlina

Playlist Browser with Swift

1 Answer

Michael Reining

Michael Reining