Warning about missing self links

[gadomski]

While the spec says self links are strongly recommended (e.g. from the item-spec),

the best practices have multiple locations where a self link is not recommended for all objects in a tree. E.g. in Self-contained:

Only relative href's in structural links ... This also implies no self link, as that link must be absolute.

And Relative published:

This is designed so that a self-contained catalog (of either type, with its assets or just metadata) can be 'published' online by just adding one field (the self link) to its root (Catalog or Collection).

IMO currently warning every time a self link is missing is a false positive, and the warning should either be dropped or put-behind an opt-in flag. I also think this could/should also be opened an issue in stac-spec itself.

[jonhealy1]

Maybe a WARNING isn't always necessary for something that may just be a 'recommendation' too?

[jonhealy1]

@gadomski Do you think I should remove this check entirely? Making it conditional on different types of collections is an option maybe, but I don't know if it's achievable? What do you think?

[philvarner]

in stac-api-validator, I feel like there are some things that are currently warnings that are more like "are you sure you meant to do this?" -- for example, when datetime values that are not RFC 3339-compliant are accepted.

I wouldn't remove it entirely.

I think you can probably come up with a good heuristic.

The other option is having the ability to turn off specific checks link most linters do, so an implementer who intentionally didn't have self links could explicitly turn that warning off.