Mod config files

A mod can ship JSON config files and read them into your own classes with one call. New in 0.2.0.

RegisterConfig sits on the mod base class on both sides, so the usage is identical. What differs is which folder the file is read from, and that matters more than it sounds: see Client and server config.

Defining a config class

An ordinary class with defaults. No attributes, no config serializer:

MyConfig.cs (in the shared project, or per side)

public class MyConfig
{
    public int MaxPlayers { get; set; } = 4;
    public bool AllowFastTravel { get; set; } = true;
    public string WelcomeMessage { get; set; } = "Have fun";
}

Registering it

Call RegisterConfig<T> from your mod's RegisterServices on the client, or Init on the server:

protected override void RegisterServices(IDependencyContainer services)
{
    RegisterConfig<MyConfig>();
}

That reads config.json from the mod's folder and registers the result as a singleton, so anything resolved from the container can take it as a constructor parameter:

public class GreetingSystem(MyConfig config, IOblivionChatApi chat)
{
    public void Greet() => chat.ShowLocalMessage(config.WelcomeMessage, Color.White);
}

The matching file goes in the mod folder:

config.json

{
  "maxPlayers": 6,
  "welcomeMessage": "No cheating"
}

Key matching is case-insensitive, comments and trailing commas are allowed, and any key you leave out keeps the default from the class. The example above leaves allowFastTravel as true.

Multiple files

Pass a file name to split configs up:

RegisterConfig<MyConfig>();                 // config.json
RegisterConfig<ArenaConfig>("arenas.json"); // arenas.json

Each call registers its own type, so the two resolve independently.

What happens when the file is wrong

Case	Result
File is missing	The defaults from the class are used, and a warning is logged
File does not parse	ModConfigException is thrown and the mod fails to load
File has a key the class does not declare	ModConfigException is thrown, naming the key

That last one is deliberate. A typo in a config key is otherwise invisible: you write maxPlayer, nothing happens, and you have nothing to go on.

Client and server config

The API is opt-in and independent per side. A mod that never calls RegisterConfig reads nothing, and no default file is created for it.

Because a mod's client and server halves live in different folders, they read different files:

• RegisterConfig in a client mod reads from the mod's client/ folder, which is handed to every player.
• RegisterConfig in a server mod reads from the mod's server/ folder, which never leaves the server.

So server-only settings belong in the server half, where they stay private. See Mod management for the folder structure.

warning

Do not put anything sensitive in a client config file. Everything in client/ is sent to every player who joins, so treat it as public.