Add cd number to album model

[adamcik]

Our current model for albums has no good way of storing metadata for multi cd albums. Having a field for cd number and number of cds might be enough

This is somewhat related to #263.

[jodal]

Something like Track.disc_no and Album.num_discs, to be exact? Maybe default both to 1?

On a related note, I haven't found anything on how libspotify handles multidisc albums. Anybody got an example album I can look at?

[adamcik]

I would default to None as most of the time we don't really know anything about this. I imagine cases where this also might not make sense.

[trygveaa]

@jodal: Tracks in libspotify have a disc number associated with them which can be retrieved by sp_track_disc(track) in libspotify or track.disc() in pyspotify. However this number doesn't seem to be initialized until you do an albumbrowse on the album the disc is in.

I did this test:

• Lookup track by url.
• Wait until track is loaded.
• Check disc number, it was 0.
• Get the album the track is from.
• Check that the album is loaded (it wasn't necessary to wait).
• Call sp_albumbrowse_create on the album.
• Check disc number, it was 0.
• In the albumbrowse callback, check disc number on the same track object. This time it was correct.

It also doesn't seem to be possible to get the number of discs an album consist of, other than by traversing all the tracks and checking the highest disc number.

The example album I used was spotify:album:3LymDdEISKszJqeN2z9DBI.

[jodal]

Fixed by #315.

[adamcik]

What about actually populating the field? Could you open an issue for that if we don't have one. And then there is the other issue of tricking mpd into understanding this by using say '%d%02d' %(disc_num, track_num)

[jodal]

Opened #317 and #318.