从Spotify iOS SDK 3.0中的多个播放列表创建曲目阵列

Question

I was able to do this with CocoaLibSpotify, but I can't figure out how it should be done in the new Spotify iOS SDK.

I'm trying to create an array of tracks from multiple playlists that I load in via their URIs. The goal here is to be able to play, at random, tracks from across a set of playlists.

I've been able to load in a playlist from its URI, it's represented as an SPPlaylistSnapshot. There doesn't seem to be a way to get the individual tracks from this SPPlaylistSnapshot so I can create a pool that I can add to and draw from.

Does anyone know a way to do this?

Answer 1

SPTPlaylistSnapshot has firstTrackPage property, which contains the first x tracks, where x is a number I can't remember. With that first page, you can request additional pages until you have all the tracks.

See the documentation for SPTPlaylistSnapshot and SPTListPage for details.

Answer 2

After authentication, define a playlist request , like this:

let playListRequest = try! SPTPlaylistList.createRequestForGettingPlaylists(forUser: userName, withAccessToken: token)

I use alamofire to post this request:

Alamofire.request(playListRequest)
        .response { response in


            let list = try! SPTPlaylistList(from: response.data, with: response.response)

            for playList in list.items  {
                if let playlist = playList as? SPTPartialPlaylist {
                    print( playlist.name ) // playlist name
                    print( playlist.uri)    // playlist uri

                    let stringFromUrl =  playlist.uri.absoluteString
                    let uri = URL(string: stringFromUrl)
                    // use SPTPlaylistSnapshot to get all the playlists
                    SPTPlaylistSnapshot.playlist(withURI: uri, accessToken: token!) { (error, snap) in
                        if let s = snap as? SPTPlaylistSnapshot {
                            // get the tracks for each playlist
                            print(s.name) 

                            for track in s.firstTrackPage.items {
                                if let thistrack = track as? SPTPlaylistTrack {

                                    print(thistrack.name)

                                }
                            }
                        }


                    }
                }
            }
    }

Answer 3

Basically what everyone's saying is correct, use SPTPlaylistSnapshot to get the tracks for the playlist, here's my code for getting all the items in a playlist in Swift 3.

func getTracksFrom(page:SPTListPage, allItems:[SPTPlaylistTrack]) -> [SPTPlaylistTrack] {
    guard let items = page.items as? [SPTPlaylistTrack] else {print("empty page");return allItems}
    var allTracks = allItems
    allTracks.append(contentsOf: items)

    var nextPage = SPTListPage()

    if page.hasNextPage {
        page.requestNextPage(withAccessToken: (SPTAuth.defaultInstance().session.accessToken)!) { (error, data) in
            guard let p = data as? SPTListPage else {return}
            nextPage = p
        }

        return getTracksFrom(page:nextPage,allItems:allTracks)
    }
    return allTracks
}

func getAllTracksFrom(_ playlist:SPTPlaylistSnapshot) -> [SPTPlaylistTrack]  {
    var allTracks:[SPTPlaylistTrack] = []
    allTracks = getTracksFrom(page: playlist.firstTrackPage, allItems: allTracks)
    return allTracks
}

override func viewDidLoad() {
    super.viewDidLoad()
    guard let p = playlist else {return}
    SPTPlaylistSnapshot.playlist(withURI: p.uri, accessToken: (SPTAuth.defaultInstance().session.accessToken)!, callback: { (error, dataOrNil) in
        guard error == nil else {print(error!);return}
        guard let playlistSnapshot = dataOrNil as? SPTPlaylistSnapshot else {print("couldn't cast as SPTPlaylistSnapshot");return}
        self.tracks = self.getAllTracksFrom(playlistSnapshot)
        self.tableView.reloadData()
    })
}