/// <summary>
/// Retrieves a list of all tracks found in the given playlist.
/// </summary>
/// <param name="playlistID">The unique PersistentID of the playlist to examine.</param>
/// <returns></returns>
/// <remarks>
/// iTunes allows users to create multiple playlists with the same name. So we
/// must use the PersistentID of the playlist instead of its canonical name.
/// </remarks>
public override PersistentIDCollection FindTracksByPlaylist(PersistentID playlistID)
{
if (!isReady)
{
return(new PersistentIDCollection());
}
// find the <plist><dict><key>Playlists</key><array> root node
var playlistRoot =
from node in root
.Element(ns + "dict")
.Elements(ns + "key")
where node.Value == "Playlists"
select node.NextNode;
// find the parent <array><dict> node of the named playlist
// <array><dict><key>Name</key><string>Library</string>
var playlistNodes =
from node in ((XElement)playlistRoot.Single())
.Elements(ns + "dict")
.Elements(ns + "key")
where node.Value == "Playlist Persistent ID" &&
((XElement)node.NextNode).Value == (string)playlistID
select node.Parent;
// collect all Track ID values from this playlist
var trackIDs =
from node in ((XElement)playlistNodes.Single())
.Elements(ns + "array")
.Elements(ns + "dict")
.Elements(ns + "key")
where node.Value == "Track ID"
select node.NextNode;
// find the <plist><dict><key>Tracks</key><dict> root node
var trackRoot =
from node in root
.Element(ns + "dict")
.Elements(ns + "key")
where node.Value == "Tracks"
select node.NextNode;
// join tracks on trackID to extract the persistent IDs
var tracks =
from node in
(from node in ((XElement)trackRoot.Single()).Elements(ns + "key")
join id in trackIDs on((XElement)node).Value equals((XElement)id).Value
select((XElement)node.NextNode)
).Elements(ns + "key")
where ((XElement)node).Value == "Persistent ID"
select PersistentID.Parse(((XElement)node.NextNode).Value);
PersistentIDCollection list = new PersistentIDCollection(tracks.ToList <PersistentID>());
return(list);
}
/// <summary>
/// Retrieves a list of all tracks by the specivied artist on the named album.
/// </summary>
/// <param name="album">The name of the album.</param>
/// <param name="artist">The name of the artist.</param>
/// <returns></returns>
public override PersistentIDCollection FindTracksByAlbum(string album, string artist)
{
if (!isReady)
{
return(new PersistentIDCollection());
}
album = album.Trim().ToLower();
artist = artist.Trim().ToLower();
// find the <plist><dict><key>Tracks</key><dict> root node
var trackRoot =
from node in root
.Element(ns + "dict")
.Elements(ns + "key")
where node.Value == "Tracks"
select node.NextNode;
// Tracks/dict is the container for all tracks where each is a key/dict pair
// collect all dict elements related to specified album
var albumTracks =
from node in
(from node in ((XElement)trackRoot.Single())
.Elements(ns + "dict")
.Elements(ns + "key")
where node.Value == "Album" &&
((XElement)node.NextNode).Value.Trim().ToLower() == album
select node.Parent
).Elements(ns + "key")
where node.Value == "Artist" &&
((XElement)node.NextNode).Value.Trim().ToLower() == artist
select node.Parent;
// collect all persistent IDs from these dict elements
var tracks =
from node in albumTracks.Elements(ns + "key")
where node.Value == "Persistent ID"
select PersistentID.Parse(((XElement)node.NextNode).Value);
PersistentIDCollection list = new PersistentIDCollection(tracks.ToList <PersistentID>());
return(list);
}