How to make some option resilient?

[Asqiir]

I would like to be able to predefine some options in nix as "whatever value is here should survive a home-manager switch".

I imagine it to work like this:

config.programs.plasma.configFile.<file>.<segement>.<option> = mkResilient;

This would be part of the activationScript. It needs to read from the configfile before deletion, and write afterwards.

In some cases, I would prefer this over excluding the entire script from override.

[toast003]

I'm not sure what you mean?

Tried looking up what mkResilient is but I could not find anything

[Asqiir]

The point of this question is "is there already an option that works kinda like this (and of not, what is your opinion on whether there should be such a thing)".

Now that I think of it persistent fits better than resilient does.

[toast003]

Ok, I think what you mean now.
We don't have anything that does this rn, although I could see it being implemented after #94 lands (no promises tho :P)

[toast003]

Imo it should call it mutable instead of persistent (look at users.mutableUsers in NixOS), so for example if you wanted to make the amount of desktops mutable you could do something like this:

programs.plasma.configFile = {
  "kwinrc"."Desktops"."Number" = {
    mutable = true;
  };
};

[magnouvean]

The reason why I made immutable instead of mutable was mainly because I thought it made more sense to make something "immutable" than "not mutable" (mutable sort of is the default). It still can change though if there is some reason to do so. Regarding adding options for making things resilient I guess we could add such an option now as it's more approachable after #94 was merged, though it isn't really that trivial to implement right now (we probably would need to rewrite the config-writing script) and some other things probably is a bit more important a.t.m..