Cauldron Tweaker Sample Code

Below is a sample script, written in JavaScript, to register two new cauldron behaviors through the Cotton Tweaker system. It would be placed at the location data/cotton/tweaker/cauldron_sample.js.

//Classes to construct using lambdas
var Predicate = Java.type('java.util.function.Predicate');
var CauldronBehavior = Java.type('io.github.cottonmc.cotton.cauldron.CauldronBehavior');

//construct a predicate that will only work if:
// - the cauldron has at least one bottle of water in it
// - the cauldron has no other inserted items
// - the catalyst is a block of sand
var clayPred = new Predicate(function(ctx) {
    return ctx.getLevel() >= 1
        && ctx.getFluid() === TweakerUtils.getFluid("minecraft:water")
        && TweakerUtils.isItemListEmpty(ctx.getPreviousItems())
        && TweakerUtils.getStackItem(ctx.getStack()) === TweakerUtils.getItem("minecraft:sand");
});

//construct a behavior that will:
// - remove one sand from the catalyst stack
// - remove one bottle of water from the cauldron
// - give one block of clay to the activator
// - play a sound effect of a bucket filling
var clayBehav = new CauldronBehavior(function(ctx) {
    CauldronTweaker.takeItem(ctx, 1);
    CauldronTweaker.drainCauldron(ctx, 1);
    CauldronTweaker.giveItem(ctx, TweakerUtils.getItem("minecraft:clay"), 1);
    CauldronTweaker.playSound(ctx, TweakerUtils.getSound("item.bucket.fill"), 1, 1);
});

//construct a predicate that will only work if:
// - the cauldron has at least three bottles of water in it
// - the cauldron has no other inserted items
// - the catalyst is an ender eye
var enderPred = new Predicate(function(ctx) {
    return ctx.getLevel() >= 3
        && ctx.getFluid() === TweakerUtils.getFluid("minecraft:water")
        && TweakerUtils.isItemListEmpty(ctx.getPreviousItems())
        && TweakerUtils.getStackItem(ctx.getStack()) === TweakerUtils.getItem("minecraft:ender_eye");
});

//construct a behavior that will:
// - remove one ender eye from the catalyst stack
// - remove three bottles of water from the cauldron
// - spawn an enderman above the cauldron
var enderBehav = new CauldronBehavior(function(ctx) {
    CauldronTweaker.takeItem(ctx, 1);
    CauldronTweaker.drainCauldron(ctx, 3);
    CauldronTweaker.spawnEntity(ctx, TweakerUtils.getEntity("minecraft:enderman"));
});

//register the behaviors!
CauldronTweaker.registerBehavior(clayPred, clayBehav);
CauldronTweaker.registerBehavior(enderPred, enderBehav);