Feature request: index value formatting

[simoncn]

I should be able to extend the current support for the indexFormat option in the tagFormat property to enable indexFormat to be used for other tags as well as Artist.

These indexFormat options would be applied from left to right to each item (track or group) and would not replace any existing tags in the item. For example, if you specify

workbytitle.indexFormat={$title$tonality$opusnumber$subtitle}

this would add a workbytitle tag if it doesn't exist in this item. No tag would be added if the item already has a workbytitle tag.

The processing of indexFormat would occur later than the processing of tagOptions and tagValue, so any new tags created by indexFormat would not have tagOptions or tagValue customizations applied to them.

When processing the tags in the format string, the index values of these tags will be used.

If a custom sort value has been applied to the first tag that is processed by the format string, this custom sort value will be applied to the new tag that is created by indexFormat.

The processing of indexFormat would take place while scanning the library. This is unlike displayFormat processing, which takes place during browsing. If you have a large library, the overhead of doing indexFormat processing might increase scanning time significantly.

Would this enable you to do what you want?