Track-Level metadata during candidate selection

[pSpitzner]

Hi all,

for beets-flask we are considering to add detailed track-level previews, and I'd like to get some input from the experts around.

The aim is to show users the info that an imported track will have after the import is done. In essence, this means we want to get the track-level metadata during candidate selection.

We currently manage to do this well for album level data. However, since this is not the final info of music files, we are often left wondering what we will end up with — especially for single-track albums like bootlegs.

Together with the info we have in the Full Metadata view of the as-is candidate, this would allow a neat before-after comparison (2nd screenshot)

Difficulties

• Candidates can be fetched easily without moving files. But they are album-level entities.
• Details such as final file path depend on the current library state and beets config. Thus, not part of the candidate.
• Plugins may alter track-level metadata. They only do so once they run, and we have no way to find out beforehand.

Current ideas

• Go through the full import pipeline without actually moving or altering files. But can we get all needed data this way?
• Go through the full import pipeline, copy files, grab information, and undo the import immediately after. Seems robust, but slow and inefficient.
• Better suggestions?

Clearly, both approaches are not ideal, and since this might be a feature better suited for beets than for beets-flask, I though I check before duct-taping a solution. After all, track-level info would also be nice via cli.

Cheers,
p