Creating and Modifying Slots

If the information below is still leaving you with questions, you can look at each platform's test mod [Fabric, Neoforge] for starting points. You can also ask questions within the Discord for more assistance.

Creating a slot within Accessories requires you follow the two options available to you:

Datapack Method: Allows for full ability to tweak Slot Properties and its bound Entities within json data files loaded on server start
Programmatic Method: More restrictive control over a given slot type via the Unique Slot API

Notice for Datapacks

When using the Datapack method its recommended that you design your mod with the ability to be adjusted by end users/other datapackers. This is because of Accessories base systems, which allow for items to be moved from one slot to another, removed from your slot, or even preventing an item from being equipped in any slot.

It may be your intention to provide some sense of balance, but this will lead to issues for Modpack makers, who usually want to balance around other mods.

Data Pack Format¶

To create your own slot type or adjust an existing slot, you will need to need to make a new .json file at the following location, data/{replace_with_pack_namespace}/accessories/slot/, that is named as the slots name.

For Unique slots: it is required that you have the namespace of the given slot within the folder structure as follows: data/{replace_with_pack_namespace}/accessories/slot/{unqiue_slot_namespace_here}/.

Below is an example of the back slot file located within Accessories here:

{
  "replace": false,
  "amount": 1,
  "operation": "set",
  "order": 1000,
  "icon": "accessories:gui/slot/back"
}

Field Keys	Data Type	Description
`"order"`	Integer	The number which decides in what order the slot will appear inside the Accessories Screen. Lower numbers are placed first and higher numbers are placed last
`"amount"`	Integer	Used when calculating the base size of the given slot using the given operation's: `"set"`, `"add"`, or `"remove"`
`"operation"`	String	The specific operation used in combination with the specified `amount`
`"validators"`	String[]	The ResourceLocation's (`Identifier`) of all predicates to be used for the given slot
`"drop_rule"`	String	The specific rule used when attempting to drop the Accessories: `"default"`, `"keep"`, `"drop"`, `"destroy"`
`"icon"`	String	The resource location of the given slot icon in which is used to find the texture within the block atlas

Icon Location

It is recommended that the location for the icon follows the assets/{replace_with_pack_namespace}/gui/slot/ convention. This is because any textures here are put within the block atlas (to allow for ticking). If this is not followed, it is up to the developer to add the texture to the block atlas for rendering to work

To modify existing slots there are multiple methods to such:

Modify Amount: Create a file with the same same path and same name with adjustments to amount either though the add or remove operation type
Replace File: Create a file with the same namespace, same path, and same name that you then adjust with the replace field set to true which will replace
Replace Data (Requires Datapack Ordering): Move your datapack using some tool or method(Not included by default) that allows for the adjustment of ordering allowing for your slot file to apply after the inital one allowing you to modify aspects of such

Unique Slot API¶

This API is the alternative method for creating a slot which comes with the benefits of being able to lock down various aspects of a slot like equipability, which Entity a slot is bound to, and prevents certain operations like resizing from occurring.

Note that unique slots will not show up in the main Accessory Screen. Wit this you get the freedom to implement your own custom screen/system using Accessories as your backend/API target to interact with inventory.

A breakdown of how such is to implement is below:

public class UniqueSlotExample implements UniqueSlotHandling.RegistrationCallback  {
    private static final ResourceLocation MAGIC_BALL_PREDICATE = ResourceLocation.fromNamespaceAndPath("example", "magic_ball");

    public static final UniqueSlotExample INSTANCE = new UniqueSlotExample();

    private UniqueSlotExample(){
        SlotPredicateRegistry.registerPredicate(slotPredicate1, SlotBasedPredicate.ofItem(item -> item.equals(ExampleItems.MAGIC_BALL)));
    }

    private static SlotTypeReference MAGIC_BALL_REFERENCE;

    @Override
    public void registerSlots(UniqueSlotHandling.UniqueSlotBuilderFactory factory) {
        MAGIC_BALL_REFERENCE = factory.create(ResourceLocation.fromNamespaceAndPath("example", "magic_ball"), 1)
                .slotPredicates(MAGIC_BALL_PREDICATE)
                .validTypes(EntityType.PLAYER)
                .build();
    }

    @Nullable
    public static SlotTypeReference magicBallRef() {
        return MAGIC_BALL_REFERENCE;
    }

    // Call init method within your mods initializer to add the class to the main Unique Slot Handling event
    public static void init() {
        UniqueSlotHandling.EVENT.register(UniqueSlotTest.INSTANCE);
    }
}

Slot Initialization

You must call the init function of the example class or register the event invoker yourself

The given factory object that is returned by the registered method invocation or implementing object allows you to get a UniqueSlotBuilder which has the following methods:

Field Keys	Description
`slotPredicates(ResourceLocation... locations)`	Used to pass the desired Slot Predicates for this slot as none are set by default
`validTypes(EntityType<?>... types)`	Used to pass any entity types that should be bound with this slot
`strictMode(boolean value)`	Used to prevent any modifications to key data like the given slot predicates or what entity have this slot bound
`allowResizing(boolean value)`	Used to prevent adjustments to the slot amount either though datapack or attributes
`allowEquipFromUse(boolean value)`	Used to prevent any Accessory valid for this slot type from being quickly equipped from hand
`allowTooltipInfo(boolean value)`	Used to prevent any tooltip information about this slot from appearing within a given Accessories Tooltip

Last update: 2024-12-26