Add ABAP Language Version to Repo Settings (experimental)

[mbtools]

Enhance UI to select ABAP Language Version (only visible if ALAV experimental feature is enabled)

Repo Settings:

Ref #6154, #6298

[larshp]

good to merge

however, suggest adding a link to some documentation describing how it exactly works/what is the impact when changing these settings, seen from a user perspective

[fabianlupa]

+1 for docs, I didn't quite following all the discussions on this and would be curious if you can "mix" the ABAP Language Version (ALV? ALaV?) with subpackages. I. e. a repo that works onpremise and in the cloud but has onpremise or cloud specific subpackages that only get pulled where supported. Or if that requires separate repos / some kind of branching strategy.

[larshp]

but has onpremise or cloud specific subpackages that only get pulled where supported

I'd recommend against such a setup. Git does always try to sync local and remote, and if having such a package setup, it will by design never be in sync.

do a big package that is compatible with all target versions, and some smaller separate packages if something is version specific

[mbtools]

We will certainly document it. I will change the "Undefined" option to "Any (Object-specific ABAP Language Version)". This matches the current abapGit: Each object serializes/deserializes its own ABAP Language Version. We can continue to build "big packages" as Lars suggested.

The other settings come into play when a project is running in a specific environment, only. For example, when you develop something for BTP (ABAP Cloud) using released classes that don't exist on-prem. Or the other way, you use classic features (Standard ABAP) that will never run in ABAP Cloud. Making this explicit in the metadata will also allow searching for/filtering of projects and avoid "try pulling it in a system to see if it will work" scenarios.

[fabianlupa]

That also means from an end user / developer perspective 3 repos for an application targeting both onprem and cloud? 3 repos to update, keep in sync, manage cross repo PRs etc.?

1. Main repo, needs to work in all environments -> language version ABAP for Cloud Development (?) without usage of cloud specific APIs
2. OnPremise "addon" repo -> language version Standard
3. Cloud "addon" repo -> language version ABAP for Cloud Development

I'd be interested to know if there are better / more convenient strategies, though this is not the right place to discuss this :)

[larshp]

its not the right place :) lemme continue

for a setup like https://blogs.sap.com/2023/09/11/proof-of-concept-migrating-segw-project-to-abap-cloud/, there would only be "1. Main Repo" and no 2 and 3, they would be manual scaffolding like https://github.com/abap2UI5/abap2UI5#installation

I'd recommend having as much code as possible in 1, and very small 2 and 3's if needed. This does require compromises, but the other alternative is double maintenance which is worse than a lot of things

or have one main repo, with automatic translations to the opposite target, can get a long way using just sed