Track : Nullable string fields

[sandreas]

The problem

In https://github.com/sandreas/tone/issues/15#issue-1292428672 I try to remove metadata properties completely which does not work as expected.

Unfortunately I did not find a way to completely remove a property - just set it to empty string, which is not the same in my opinion.

My question: Is there a way to get rid of an existing string property - so REALLY removing it?

Code To Reproduce Issue [ Good To Have ]

// ATL.Settings.NullAbsentValues = true; // does not change the behaviour in any way (which is good)
var track = new Track("a-file.m4b");
track.Album = null; // does nothing instead of removing the property, which I had expected
// track.Album = ""; // sets the property to empty string (and does not remove it)
track.Save();

I would:

• remove the property on setting it to null (regardless of the properties type, e.g. Track.RecordingDate = null should remove it)
• set the property to empty string on strings with Track.Album = ""; (as it is now)
• introduce a new setting Settings.TreatDefaultValuesAsNull = true;
  • keep the current behaviour on Settings.TreatDefaultValuesAsNull = true;, e.g. Track.TrackNumber = 0; removes it?
  • set the property to the given value on Settings.TreatDefaultValuesAsNull = false;, e.g. Track.TrackNumber = 0;

What do you think?

[Zeugma440]

With the current API :

• To completely remove a non-string field, you can :
  • Either set Settings.NullAbsentValues = true and set the field to null
  • Or keep the default of Settings.NullAbsentValues and set the field to its default value (0 for numbers, DateTime.MinValue for dates)
• To completely remove a string field, you should set the field to "" (empty string)
• As a consequence to this convention, it is not possible to set a field to the value ""

I have not forgotten you've made a convincing case to evolve the API to allow nullable strings. I just need some time for this to happen, as it is a major evolution. For now, please cope with setting empty strings.

I'll keep that issue open as a reminder. Thanks for your understanding~

[sandreas]

With the current API :

Thank you for clarifying this :-) I think this description would also make a decent FAQ entry, that can be updated as soon as this has been changed.

[sandreas]

So to summarize, currently, we have the following types with the according values to remove the value:

• int (e.g. DiscNumber) => 0
• string (e.g. Album) => ""
• DateTime (e.g. PublishingDate) => DateTime.MinValue
• float (e.g. Popularity) => 0.0f

But what about these? Are my assumptions correct? (especially about Lyrics):

• LyricsInfo (Lyrics) => null
• IList<ChapterInfo> ( Chapters) => new List<ChapterInfo>() or Track.Chapters.Clear()
• IList<PictureInfo> (EmbeddedPictures) => new List<PictureInfo>() or Track.EmbeddedPictures.Clear()
• IDictionary<string, string> (AdditionalFields) => new Dictionary<string, string>(); or Track.AdditionalFields.Clear()

[Zeugma440]

Let me rephrase that

Removing simple fields

Field type	Value when Settings.NullAbsentValues is false	Value when Settings.NullAbsentValues is true
int	0	null
float	0.0f	null
DateTime	DateTime.MinValue	null
string	""	""

Removing complex fields

Field	Value
Lyrics	Touché... setting to null doesn't work ! There's no way to remove lyrics at the moment 😅
Chapters	new List<ChapterInfo>() or Track.Chapters.Clear()
EmbeddedPictures	new List<PictureInfo>() or Track.EmbeddedPictures.Clear()
AdditionalFields	new Dictionary<string, string>() or Track.AdditionalFields.Clear()

=> During the upcoming API evolution, I'll make it so setting null to Lyrics actually removes them.

[sandreas]

Touché... setting to null doesn't work ! There's no way to remove lyrics at the moment 😅

Ahaa! I knew I had super nitpicking powers! ;)

=> During the upcoming API evolution, I'll make it so setting null to Lyrics actually removes them.

Great, thank you. I'm really exited about this evolution. If you need my nitpicking to you help with that, just ask =D I'm really impressed with the improvements you did since I started asking the sh.. out of you. You really DO care about your stuff!

[Zeugma440]

I haven't had the time to initiate any API evolution, but I did make a small change to be able to remove lyrics.

Setting Track.Lyrics to null now works as expected since today's v4.23

[sandreas]

Cool, thank you. I did not have the time to do anything in the last weeks... although I have already put some effort in an AdvancedTrack, its not gonna finish in the next month. Lots of things are happening atm ;) I'll keep you updated.