Document asset rel

[mojodna]

rel establishes the relationship between the current document and the linked asset.

Common relationships include: "thumbnail" (usually singular), "visual" (1+), "analytic" (1+), "qa" (1+).

This currently complements the asset key, particularly in scenarios where it would need to be parsed to determine its relationship (e.g. visual-1, visual-SWIR, etc.)

Refs #308
Refs #309

PR Checklist:

• This PR has no breaking changes.
• I have added my changes to the CHANGELOG or a CHANGELOG entry is not required.
• API only: I have run npm run generate-all. to update the generated OpenAPI files.

[matthewhanson]

I don't think this is sufficient to do what we need, because as you pointed out in #308, a visual product could be spread out over multiple files and this wouldn't be able to depict that because there's no order specified anywhere.

I think these different use cases are better off defined in the Asset definition.

[ghost]

I'm not sure if there is enough of a difference between type and rel for me. Both of them use thumbnail as a primary example.

[m-mohr]

The value for the field type must be a media type according to the spec. thumbnail as type would be invalid and should be replaced with image/.... Are you referring to another 'type', @hgs-truthe01 ?

[ghost]

@m-mohr

The asset spec says: Media type of the asset (see chapter on Media Types below).
The chapter below is a table with 1 row where type is "thumbnail".

I know we discussed mime types, but it doesn't actually say that and the one type that is listed shows thumbnail. So I think we need to de-conflict the definitions.

[m-mohr]

@hgs-truthe01 You are looking at the Asset Type chapter, but further down there's a Media Type chapter. The Asset Types are the property keys of the assets and the Media Types are for the field type. So I think you looked at the wrong table/chapter.

Nevertheless, I agree with you that a rel somewhat duplicates the property key for the asset.

[ghost]

@m-mohr I see what you are saying, but that is actually even more confusing then. Asset Type needs to be renamed to something like Asset Name. We have 3 tables in a row that are all "types". If it said "Asset Key Name", "Asset Relation", and "Media Type" it might make more sense.

[matthewhanson]

Closed in favor of #637