Custom factories

Problem

When you registration your CustomItemStack, for default Library used default factory. Sometimes need an inject dependency into your CustomItem.

For example take CustomItemStack (MyItemStack):

@CustomItem(type = Material.BARRIER, customModelData = 10)
public class MyItemStack extends AbstractCustomItemStack {
    public MyItemStack(@NotNull ItemStack stack, Localisation messages) throws IllegalArgumentException {
        super(stack);
        var meta = this.getItemMeta();
        meta.setDisplayName(messages.getMessageForMyItemStack());
        this.setItemMeta(meta);
    }
}

Solution

Let's see in construction exists external class of Localisation. What to do next, if we want auto created of this class?

1. Add optional parameter defaultFactory to CustomItem annotation, like:

@CustomItem(type = Material.BARRIER, customModelData = 10, defaultFactory = false)

defaultFactory = false means CustomItemsCore not be include this class automatically.

2. Register CustomFactory.

CustomItemStackManager manager = customItemStackPlugin.getCustomItemsApi().getCustomItemStackManager();

manager.registerCustomItemStack(MyItemStack.class, new CustomItemStackFactory() {
    @Override
    public AbstractCustomItemStack build(CustomItemStackManager customItemStackManager, ItemStack itemStack) {
        return new MyItemStack(itemStack, new LocalisationImpl());
    }
});

Well done, now your Item will be creating automatically with your dependency!

Snippet's

CustomFactory with Guice:

Non production code...

    new CustomItemStackFactory() {
      
        @Override
        public AbstractCustomItemStack build(CustomItemStackManager customItemStackManager, ItemStack itemStack) {
            var itemClazz = customItemStackManager.getCustomItemStackClass(itemStack); //Get CustomItemStack class of ItemStack

            var constructor = itemClazz.getDeclaredConstructors()[0];
            var constructorParameters = constructor.getParameters();

            var parameters = new Object[constructorParameters.length];

            parameters[0] = itemStack;

            for (int i = 1; i < constructorParameters.length; i++) {
                parameters[i] = injector.getInstance(constructorParameters[i].getType());
            }
            // Handle exception's
            return (AbstractCustomItemStack) constructor.newInstance(parameters);
        }
    })