CaffeineConfig

CaffeineConfig is a mixin configuration manager that allows both the user and other mods to configure what mixins should apply and which shouldn't in a simple manner, and without the mods having to depend on each other. It is used in the Sodium and Lithium mods.

Usage

Adding CaffeineConfig as a dependency to your project

To use CaffeineConfig you'll first need to add the CaffeineMC maven to the repositories block of your build.gradle file, and then add CaffeineConfig as a dependency. You should include CaffeineConfig as Jar-in-Jar with your mod.

Adding the CaffeineMC maven to your build.gradle:

repositories {
    ...
    // TODO this when I know the url
}

Adding CaffeineConfig as a dependency and as a Jar-in-Jar in your mod:

dependencies {
    ...
    modImplementation 'net.caffeinemc:CaffeineConfig:1.0.0'
    include 'net.caffeinemc:CaffeineConfig:1.0.0'
}

While not strictly necessary, you should also declare the dependency in your fabric.mod.json:

{
    ...
    "depends": {
        ...
        "caffeineconfig": ">=1.0.0"
    }
}

Extending AbstractCaffeineConfigMixinPlugin

In order to use the core functionality, you'll need a class that extends AbstractCaffeineConfigMixinPlugin, where you'll need to implement the createConfig() and mixinPackageRoot() methods.

The mixin package root is the deepest common package between all mixins, ending with a dot. For example, if the mod has mixins in org.example.mod.mixin.feature and org.example.mod.mixin.bugfixes, the package root would be org.example.mod.mixin..

Note that while createConfig() will only be called once, the mixinPackageRoot() method will be called each time mixin asks the config plugin whether it should apply a mixin.

An example implementation of the AbstractCaffeineConfigMixinPlugin is the following:

public class ExampleModMixinConfigPlugin extends AbstractCaffeineConfigMixinPlugin {

    @Override
    protected CaffeineConfig createConfig() {
        // see next section
    }
    
    @Override
    protected String mixinPackageRoot() {
        return "org.example.mod.mixin.";
    }
}

Creating a CaffeineConfig object

In order to create a CaffeineConfig object you'll first need to get a Builder by using the CaffeineConfig.builder(modName) method. By default, this will get a logger with the mod's name and Config appended to it and use it as its logger, and set the JSON key for other mods to disable settings as lowercase(modName):options. You can override those by calling the withLogger(Logger) and withSettingsKey(String) methods of the builder.

You can also provide a url to a resource with more information about your config file by calling the withInfoUrl(String) method.

Then you have to add your various mixin options, using addMixinOption(name, default). The options don't have to point directly to a mixin file, but can point to a package instead, and that will make disabling the rule disable all mixins in the package. You have to skip the mixin package root from before when defining options. You can provide multiple options for a package and subpackages if desired, where disabling the top packet will disable all children.

If one of the options depends on another option to be enabled/disabled, you can define dependencies between options by calling addOptionDependency(optionThatDepends, dependency, requiredValue). Doing that, if any of the dependencies of an option is not the required value, the option will be disabled.

Once you're ready to build your CaffeineConfig, you'll need to pass the Path to the config file to create or read in the build() method. Doing that will already populate option overrides.

An example for creating a CaffeineConfig instance for use in a class extending AbstractCaffeineConfigMixinPlugin is the following:

    @Override
    protected CaffeineConfig createConfig() {
        return CaffeineConfig.builder("ExampleMod")
                .addMixinOption("ai", true) // ai can be disabled and it will disable all subpackages
                .addMixinOption("ai.brain", true)
                .addMixinOption("ai.goal", true)
                .addMixinOption("block.hopper", true)
                .addOptionDependency("block.hopper", "ai", true) // block.hopper will be disabled if ai is disabled
                .withInfoUrl("https://example.org")
                .build(FabricLoader.getInstance().getConfigDir().resolve("examplemod.properties"));
    }

Using your MixinConfigPlugin

In order for mixin to use your class that extends AbstractCaffeineConfigMixinPlugin, you'll need to reference it in your mixins json file by mapping a field named plugin to a string being the fully-qualified name of your class.

An example is the following:

{
  "package": "org.example.mod.mixin",
  "required": true,
  "compatibilityLevel": "JAVA_16",
  "plugin": "org.example.mod.mixin.ExampleModMixinConfigPlugin",
  "injectors": {
    "defaultRequire": 1
  },
  "mixins": [
    ...
  ]
}

Notes

Any mixin added to the config (the config being the mixins JSON file) must have a valid option related to it, else the mixin plugin will throw an IllegalStateException when applying it. This is to ensure mixins are added to the config and to prevent hard to debug problems where mixins silently don't apply because they weren't assigned to any option.

If you want to add mixins that are not configurable, you should add them to a different mixin config, that is, a different mixin json file that is therefore another entry in your fabric.mod.json.