gistfile1.js

function load_and_get(content, id) {
    var obj = content.get(id);
    if (!obj) {
        content.load(id);
        obj = content.get(id);
    }
    return obj;
}

function load_track_from_album(album, options) {
    console.log(album.urlRoot + encodeURIComponent(album.id) + '/');
    album.fetch({
        url: album.urlRoot + encodeURIComponent(album.id) + '/',
        success: options.success,
        error: options.error
    });
}

function get_tracks(albums, callback, tracks) {
    if (!tracks)
        tracks = [];
    album = albums.shift();
    if (!album) {
        console.log('done');
        callback(tracks);
        return;
    }
    load_track_from_album(album, {
        success: function(album) {
            tracks.push.apply(tracks, album.tracks.models);
            get_tracks(albums, callback, tracks);
        },
        error: function(){
            alert('error');
        }
    });
}

function track_in_playlist(playlist, track) {
    if (playlist.tracks.find(function(pl_track) {
        return pl_track.get('trackName').toLowerCase() == track.get('trackName').toLowerCase() &&
            pl_track.get('artistName').toLowerCase() == track.get('artistName').toLowerCase();
    }))
        return true;
    else
        return false;
}

function add_track_to_playlist(playlist, track, callback) {
    var data = track.getPostData();
    $.ajax({
        type: 'POST',
        url: playlist.ADD_URL,
        data:_.extend(data, {playlistid : playlist.id}),
        success: function(data) {
            callback && callback();
        },
        error: function(err) {
            callback && callback();
        }
    });
}
function add_tracks(playlist, tracks, callback) {
    track = tracks.shift();
    if (!track) {
        callback(playlist);
        return;
    }
    if (!track_in_playlist(playlist, track)){
        add_track_to_playlist(playlist, track, function() {
            console.log('[TRACK] Adding track ' + track.get('trackName'));
            add_tracks(playlist, tracks, callback);
        });
    } else {
        console.log('[TRACK] Track already in playlist: ' + track.get('trackName'));
        add_tracks(playlist, tracks, callback);
    }
}

function add_artist_to_playlist(playlist_id, artist_id) {
    var playlist = load_and_get(models.playlists, playlist_id);
    playlist.tracks = undefined;
    var artist = load_and_get(models.artists, artist_id);
    var tracks = null;

    playlist.loadTracks({success: function(tracks) {
        playlist.tracks = tracks;

        artist.loadAlbums({success: function() {
            get_tracks(artist.albums.models, function(tracks){
                console.log('Got tracks');
                add_tracks(playlist, tracks, function() {
                    console.log('[DONE]');
                });
            });
        }});
    }});
}

add_artist_to_playlist('9baee31a-c766-4b98-9d4a-1ae6445fd10d', 'Soundgarden');