Support 'attachments' (artifact hierarcies)

[raboof]

For example for soundfonts, it would be neat to support uploading example clips.

Such 'attachments' could be regular artifacts, except:

• adding a 'parent id' field
• (by default) being excluded from searches
• be shown in the UI (perhaps async) when the 'parent artifact' is shown

[lfzawacki]

This is a good thing to have and I've been thinking about how to include it. The ground work for this feature is mostly ready and the architecture you suggest is almost how I imagine it.

Today each artifact has many files (StoredFile class) ordered by date of creation and only the last one is shown as downloadable:

• Artifact 'My Soundfont': files are 'soundfont.sf2', 'soundfont_v2.sf2' (downloadable)
• The artifact is the parent to all these files (artifact_id field)

So I think we should add:

• A way to upload attachments to an artifact and not have them replace the downloadable file (maybe a flag denoting they're attachments)
• Show multimedia attachments on the side pane of the UI (like the 'More Info' urls currently do)
• A way to upload new versions of the files and show the old ones to the uploader. Not related to this issue, but something that will be easy to do as part of this work.

Anyway, thanks for opening this issue. Do you think this would solve your use case?

[raboof]

Yes, that sounds great!

As for design, I agree attachments should be StoredFile's. I'm not sure whether the attachment should be placed directly under the artifact like the main file, or if it'd make sense to create a new 'child artifact' so you can also have multiple 'versions' of each attachment. That's up to you I suppose ;).