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iOS Build a Playlist Browser with Swift Building the Music Library and Playlist Models Using a Playlist Instance

Chris Hunter
Chris Hunter
2,091 Points

I get compiler errors in the playlist.swift file stating: " 'NSDictionary' is not a subtype of 'NSString'?

I even tried adding the playlist.swift file in the package download and it doesn't work. Thanks.

8 Answers

Can you post your code, please. I've got my code open so I can hunt down the difference.

Thanks.

Chris Hunter
Chris Hunter
2,091 Points

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!

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

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

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

    let colorsDictionary = playlistDictionary["backgroundColor"] as [String:CGFloat]
    backgroundColor = rgbColorFromDictionary(colorsDictionary)

}

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)
}

}

Chris Hunter
Chris Hunter
2,091 Points

However, as I said, I copied and pasted the code from the assets posted for that file because it was giving me errors. Could it be elsewhere in my project that is giving me the problems? Thanks for your help!

Just reformatting your post ... same code ...

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!

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

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

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

    let colorsDictionary = playlistDictionary["backgroundColor"] as [String:CGFloat]
    backgroundColor = rgbColorFromDictionary(colorsDictionary)

}

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)
}
}

Which line is causing the problem? Where's the compiler error?

Chris Hunter
Chris Hunter
2,091 Points

I get that error on lines:

title = playlistDictionary["title"] as String!

let iconName = playlistDictionary["icon"] as String!

let largeIconName = playlistDictionary["largeIcon"] as String!

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

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

Thanks again!

Weird!

This might be related to how the Playlist struct is being initialised since we are in the init method.

That takes an Int to set the part of the library it is looking at. It is called from viewDidLoad() within the MasterViewController. Mine says:

let playlist = Playlist(index: index)

inside a For loop.

I'm not sure this is relevant, to be honest. I'll give it some thought and sleep on it (22:43 here). Something may come to me. For some reason, though, your Dictionary is colliding with an NSString object. I can't see where it is doing that, though.

Chris Hunter
Chris Hunter
2,091 Points

I figured it out, I had an extra set of square brackets in my dictionary in MusicLibrary. I don't know how I missed that before. Thank you very much for your help!