Fallback procedure when displayFormat results in an empty string

[winxi]

Hi Simon,

I mainly use the MusicBrainz database to tag my music files. For releases with multiple artists, MusicBrainz provides link phrases in addition to the artists themselves. These link phrases sometimes contain useful information which I want to retain when using MinimServer (e.g. ArtistA and ArtistB, ArtistA vs. ArtistB, ArtistA feat. ArtistB, ...).
Thus, for a track with the artists ArtistA and ArtistB and the link phrase ' vs. ' I apply the two ARTIST tags 'ArtistA' and 'ArtistB' and an additional custom tag named DISPLAYARTIST containing the string 'ArtistA vs. ArtistB'. In MinimServer, I add

Artist.displayFormat={$displayartist}

to the tagFormat property. This enables me to browse for ArtistA and ArtistB in the All Artists index and also to display the full displayartist string containing the link phrase at the control point and the renderer.

In my library, I've three different combinations concerning the ARTIST and the DISPLAYARTIST tags:
1) A single ARTIST tag and no DISPLAYARTIST tag
2) Multiple ARTIST tags and no DISPLAYARTIST tag (when no dedicated link phrase is available)
3) Multiple ARTIST tags and a corresponding DISPLAYARTIST tag

With the displayFormat setting from above, MinimServer displays the following for the three cases:
1) The content of the single ARTIST tag
2) 'Unknown Artist'
3) The content of the DISPLAYARTIST tag

I think that there is an inconsistency between the cases 1) and 2). It should be either 'Unknown Artist' in both these cases or the content of the single ARTIST tag in case 1) and combined ARTIST tags using the default rule in case 2 (ArtistA, ArtistB, ...). Personally, I would prefer the latter option because otherwise I'd have to apply the custom DISPLAYARTIST tag to all my files, even to those with just a single ARTIST tag.

On this occcasion I'd also like to encourage you to allow the indexValue.yearOnly tag option to be applied for all date related tags (DATE, ORIGINALDATE, RELEASEDATE) and to provide a corresponding displayValue.yearOnly tag option for these tags.

Many thanks!