Number of Albums By Artists - iphone

Question

That's my Question =)
MPMediaQuery *artistQuery = [MPMediaQuery artistsQuery];
NSArray *songsByArtist = [artistQuery collections];
How can I get the number of albums of each artists of the MPMediaItemCollections in songsByArtist ?
Exemple :
The Beatles
3 Albums
AC/DC
6 Albums
Thank You !!

Answer 1

I get number of albums and songs for artist using predicate:
MPMediaPropertyPredicate *artistNamePredicate = [MPMediaPropertyPredicate predicateWithValue:#"ArtistName" forProperty:MPMediaItemPropertyArtist];
MPMediaQuery *myComplexQuery = [[MPMediaQuery alloc] init];
[myComplexQuery addFilterPredicate: artistNamePredicate];
NSInteger songCount = [[myComplexQuery collections] count]; //number of songs
myComplexQuery.groupingType = MPMediaGroupingAlbum;
NSInteger albumCount = [[myComplexQuery collections] count]; //number of albums

Answer 2

The artistsQuery convenience constructor does not sort and group by album. artistsQuery returns an array of media item collections of all artists sorted alphabetically by artist name. Nested inside each artist collection is an array of media items associated with all songs for that artist. The nested array is sorted alphabetically by song title.
One way to keep a count of albums by artist is to enumerate through all the song items for each artist collection and use a NSMutableSet to keep track of distinct album titles associated with each song. Then add the count of the set as the value for each artist key in a NSMutableDictionary. Any duplicate album titles will not be added since a NSMutableSet will only take distinct objects:
MPMediaQuery *artistQuery = [MPMediaQuery artistsQuery];
NSArray *songsByArtist = [artistQuery collections];
NSMutableDictionary *artistDictionary = [NSMutableDictionary dictionary];
NSMutableSet *tempSet = [NSMutableSet set];
[songsByArtist enumerateObjectsUsingBlock:^(MPMediaItemCollection *artistCollection, NSUInteger idx, BOOL *stop) {
NSString *artistName = [[artistCollection representativeItem] valueForProperty:MPMediaItemPropertyArtist];
[[artistCollection items] enumerateObjectsUsingBlock:^(MPMediaItem *songItem, NSUInteger idx, BOOL *stop) {
NSString *albumName = [songItem valueForProperty:MPMediaItemPropertyAlbumTitle];
[tempSet addObject:albumName];
}];
[artistDictionary setValue:[NSNumber numberWithUnsignedInteger:[tempSet count]]
forKey:artistName];
[tempSet removeAllObjects];
}];
NSLog(#"Artist Album Count Dictionary: %#", artistDictionary);
It would be cleaner if you change the query to albumsQuery. This query groups and sorts the collection by album name. Then it is just a matter of enumerating through the array of album collections and keeping a count of the representative artist name for each album in a NSCountedSet. The counted set will track the number of times objects are inserted:
MPMediaQuery *albumQuery = [MPMediaQuery albumsQuery];
NSArray *albumCollection = [albumQuery collections];
NSCountedSet *artistAlbumCounter = [NSCountedSet set];
[albumCollection enumerateObjectsUsingBlock:^(MPMediaItemCollection *album, NSUInteger idx, BOOL *stop) {
NSString *artistName = [[album representativeItem] valueForProperty:MPMediaItemPropertyArtist];
[artistAlbumCounter addObject:artistName];
}];
NSLog(#"Artist Album Counted Set: %#", artistAlbumCounter);
You can also retrieve the count for a given object in a NSCountedSet with the countForObject: method.

Answer 3

Swift 2 translation of Bryan's answer:
var artistQuery = MPMediaQuery.artistsQuery()
var artistQuery.groupingType = MPMediaGrouping.AlbumArtist
var songsByArtist = artistQuery.collections
var artistDictionary = NSMutableDictionary()
var tempSet = NSMutableSet()
songsByArtist.enumerateObjectsUsingBlock { (artistCollection, idx, stop) -> Void in
let collection = artistCollection as! MPMediaItemCollection
let rowItem = collection.representativeItem
let artistName = rowItem?.valueForProperty(MPMediaItemPropertyAlbumArtist)
let collectionContent:NSArray = collection.items
collectionContent.enumerateObjectsUsingBlock { (songItem, idx, stop) -> Void in
let item = songItem as! MPMediaItem
let albumName = item.valueForProperty(MPMediaItemPropertyAlbumTitle)
self.tempSet.addObject(albumName!)
}
self.artistDictionary.setValue(NSNumber(unsignedInteger: self.tempSet.count), forKey: artistName! as! String)
self.tempSet.removeAllObjects()
}
print("Album Count Dictionary: \(artistDictionary)")

Answer 4

albumsQuery us this if it helps u or see more on this link below
http://developer.apple.com/library/ios/#documentation/mediaplayer/reference/MPMediaQuery_ClassReference/Reference/Reference.html

Answer 5

Thanks Tim E, I couldn't get your code to work first time, but I modded it to this and it works now.
let artistQuery = MPMediaQuery.artistsQuery()
artistQuery.groupingType = MPMediaGrouping.AlbumArtist
let songsByArtist = artistQuery.collections! as NSArray
let artistDictionary = NSMutableDictionary()
let tempSet = NSMutableSet()
songsByArtist.enumerateObjectsUsingBlock( { (artistCollection, idx, stop) -> Void in
let collection = artistCollection as! MPMediaItemCollection
let rowItem = collection.representativeItem
let artistName = rowItem?.valueForProperty(MPMediaItemPropertyAlbumArtist)
let collectionContent:NSArray = collection.items
collectionContent.enumerateObjectsUsingBlock({ (songItem, idx, stop) -> Void in
let item = songItem as! MPMediaItem
let albumName = item.valueForProperty(MPMediaItemPropertyAlbumTitle)
tempSet.addObject(albumName!)
})
artistDictionary.setValue(NSNumber(unsignedInteger: UInt(tempSet.count)), forKey: artistName! as! String)
tempSet.removeAllObjects()
})
print("Album Count Dictionary: \(artistDictionary)")

Answer 6

Sorry for late answer.
Posting my answer in case it is helpful to someone.
Below code gets all artists group by album artist and get its all Albums and songs inside the album.
/// Get all artists and their songs
///
func getAllArtists() {
let query: MPMediaQuery = MPMediaQuery.artists()
query.groupingType = .albumArtist
let artistsColelctions = query.collections
artists.removeAll()
var tempSet = NSMutableSet()
guard artistsColelctions != nil else {
return
}
// 1. Create Artist Objects from collection
for collection in artistsColelctions! {
let item: MPMediaItem? = collection.representativeItem
var artistName = item?.value(forKey: MPMediaItemPropertyArtist) as? String ?? "<Unknown>"
artistName = artistName.trimmingCharacters(in: NSCharacterSet.whitespacesAndNewlines)
let artistId = item!.value(forProperty: MPMediaItemPropertyArtistPersistentID) as! NSNumber
// temp
let albumName = item?.albumTitle
let albumID = item?.albumPersistentID
print(albumName)
print(albumID)
// Create artist item
let artist = Artist()
artist.name = artistName
artist.artworkTitle = String(artistName.characters.prefix(1)).uppercased()
artist.artistId = String(describing: artistId)
// 2. Get Albums for respective Artist object
//--------------------------------------------
let mediaQuery2 = MPMediaQuery.albums()
let predicate2 = MPMediaPropertyPredicate.init(value: artistId, forProperty: MPMediaItemPropertyArtistPersistentID)
mediaQuery2.addFilterPredicate(predicate2)
let albums = mediaQuery2.collections
for collection in albums! {
let item: MPMediaItem? = collection.representativeItem
let albumName = item?.value(forKey: MPMediaItemPropertyAlbumTitle) as? String ?? "<Unknown>"
let albumId = item!.value(forProperty: MPMediaItemPropertyAlbumPersistentID) as! NSNumber
let artistName = item?.value(forKey: MPMediaItemPropertyAlbumArtist) as? String ?? "unknown"
let genreName = item?.genre ?? ""
let year = item?.releaseDate ?? item?.dateAdded
let dateAdded = item?.dateAdded
// Create album object
let album = Album()
album.name = albumName
album.artistName = artistName
album.genre = genreName
album.releaseDate = year
album.dateAdded = dateAdded
album.albumId = String(describing: albumId)
// Add artwork to album object
let artwork = Artwork.init(forAlbum: item)
album.artwork = artwork
// 3. Get Songs inside the resepctive Album object
//---------------------------------------------------
let mediaQuery = MPMediaQuery.songs()
let predicate = MPMediaPropertyPredicate.init(value: albumId, forProperty: MPMediaItemPropertyAlbumPersistentID)
mediaQuery.addFilterPredicate(predicate)
let song = mediaQuery.items
if let allSongs = song {
var index = 0
for item in allSongs {
let pathURL: URL? = item.value(forProperty: MPMediaItemPropertyAssetURL) as? URL
let isCloud = item.value(forProperty: MPMediaItemPropertyIsCloudItem) as! Bool
let trackInfo = TrackInfo()
trackInfo.index = index
trackInfo.mediaItem = item
trackInfo.isCloudItem = isCloud
trackInfo.isExplicitItem = item.isExplicitItem
trackInfo.isSelected = false
trackInfo.songURL = pathURL
album.songs?.append(trackInfo)
index += 1
}
}
artist.albums?.append(album)
}
// Finally add the artist object to Artists Array
artists.append(artist)
}
}