Calculated Fields: Persist Values in Database

[arladmin]

Extension

Something else

Describe the Improvement

Re extension: Calculated Fields Bundle

While it's great to see the long-due Calculated Fields functionality being implemented (directus/directus#3079), in some capacity, it's still missing the (pretty crucial) aspect of actually persisting the calculated values in the db, which is what the original FR was all about, at least from my perspective.

And as the FR has surprisingly already been closed, i'm creating this issue to continue the FR here.

[phazonoverload]

Alias fields don't return values in API requests, however as the field configuration exists in the database (including the formula), and we already know how to parse and evaluate it, I'm wondering how we can return the value via API.

I don't think persisting in the database makes sense though as it requires keeping the values in sync.

[phazonoverload]

Also just want to emphasise that the feature request originally only spoke about the alias interface which exists in the extension, but the community discussion suggested an expansion in scope. :)

[Zyles]

This is highly needed. Or you would need to wrap Directus with an in between API endpoint to do certain calculations before persisting.

On an insert or upsert you can't trust the client to do a calc and insert whatever number.

There are many use cases where the server itself needs to calculate and cache a value.