conditional-mixin

A library mod for using annotation to conditionally apply your mixins to your Minecraft mods

It is available at jitpack and my maven

Example Usages

conditional-mixin supports multiple mod loader platforms, including:

Platform	Requirements
Fabric	Fabric loader >=0.10.4
Forge	Forge >= 28 (mc1.14.4+)
NeoForge	NeoForge >= 20.5 (mc1.20.5+)

conditional-mixin does not require any extra dependencies

Import

Import conditional-mixin in gradle

Artifact ID table:

Platform	Artifact ID
Fabric	conditional-mixin-fabric
Forge	conditional-mixin-forge
NeoForge	conditional-mixin-neoforge

The following documents will use Fabric as the example. For other platforms, just replace the artifact ID accordingly

From jitpack

repositories {
    maven { url 'https://jitpack.io' }
}

dependencies {
    modImplementation 'com.github.Fallen-Breath.conditional-mixin:conditional-mixin-fabric:0.6.4'

    // Suggested, to bundle it into your mod jar. Choose a method your build system provides
    include 'com.github.Fallen-Breath.conditional-mixin:conditional-mixin-fabric:0.6.4'
}

From my maven

repositories {
    maven { url 'https://maven.fallenbreath.me/releases' }
}

dependencies {
    modImplementation 'me.fallenbreath:conditional-mixin-fabric:0.6.4'

    // Suggested, to bundle it into your mod jar. Choose a method your build system provides
    include 'me.fallenbreath:conditional-mixin-fabric:0.6.4'
}

Integrate

You need to create a mixin config plugin to provide the ability to control mixin applications. Then, there are 2 ways to integrate it with conditional-mixin:

The simplest way

Let your mixin config plugin class inherit RestrictiveMixinConfigPlugin

The RestrictiveMixinConfigPlugin will disable those mixins that don't satisfy with the annotated restriction in its shouldApplyMixin method

import me.fallenbreath.conditionalmixin.api.mixin.RestrictiveMixinConfigPlugin;

public class MyMixinConfigPlugin extends RestrictiveMixinConfigPlugin
{
    // ...
}

Specify the mixin config plugin class in your mixin meta json, if you have not done that yet:

"plugin": "my.mod.MyMixinConfigPlugin",

The universal way

If you have already written a custom mixin plugin and don't want to make your plugin class inherit from something else, you can directly use the RestrictionChecker provided by conditional-mixin

import me.fallenbreath.conditionalmixin.api.checker.RestrictionChecker;
import me.fallenbreath.conditionalmixin.api.checker.RestrictionCheckers;

public class MyMixinConfigPlugin
{
	private final RestrictionChecker restrictionChecker = RestrictionCheckers.memorized();
	
	// See RestrictiveMixinConfigPlugin for usages of a RestrictionChecker
}

(optional) To erase @Restriction annotations on output mixined classes, you can use me.fallenbreath.conditionalmixin.api.mixin.AnnotationCleaner and call AnnotationCleaner.create(Restriction.class) to get an annotation cleaner

See also: source code of the RestrictiveMixinConfigPlugin class

Annotate your mixins

Now, you can annotate your mixins like these:

@Restriction(
        require = {
                @Condition("some_mod"),
                @Condition(value = "another_mod", versionPredicates = "2.0.x"),
                @Condition(value = "random_mod", versionPredicates = {">=1.0.1 <1.2", ">=2.0.0"}),
        }
)
@Mixin(SomeClass.class)
public abstract class SomeClassMixin
{
    // ...
}

or

@Restriction(
        require = @Condition(type = Condition.Type.MIXIN, value = "my.mod.mixin.ImportantMixin"),  // should be another mixin in your mod
        conflict = @Condition("bad_mod")
)
@Mixin(AnotherClass.class)
public abstract class AnotherClassMixin
{
    // ...
}

You can also define your own tester class for more complicated condition testing

@Restriction(
        require = @Condition(type = Condition.Type.TESTER, tester = MyConditionTester.class)
)
@Mixin(RandomClass.class)
public abstract class RandomClassMixin
{
    // ...
}

public class MyConditionTester implements ConditionTester
{
	@Override
	public boolean isSatisfied(String mixinClassName)
	{
		// More complicated checks go here
		return mixinClassName.length() % 2 == 0;
	}
}

Notes

If you are upgrading conditional-mixin from older version, and your mixin plugin class inherits from RestrictiveMixinConfigPlugin, make sure to check if you have overwritten some methods in your mixin plugin class, since class RestrictiveMixinConfigPlugin might implement more methods of IMixinConfigPlugin in newer versions. e.g. RestrictiveMixinConfigPlugin#preApply and RestrictiveMixinConfigPlugin#postApply are added in v0.2.0 for being able to automatically remove the @Restriction in the merged target class