Recipes

Adding recipes to your addon

Recipes files are placed under recipes/<namespace>/type, where the namespace is the namespace of the addon that registered this recipe type (minecraft for Minecraft recipe types) and type the name of the recipe type.
For more information about the recipe format and default recipe types, read the admin page on it.

Creating a custom Recipe Type

Recipe types are registered over the RecipeTypeRegistry.
All of the following values are required to create a new RecipeType:

Name	Type	Usage
dirName	String	The name for the directory of your recipe type.
recipeClass	KClass<T>	The class of your recipe type, must be a subclass of NovaRecipe.
group	RecipeGroup<T>?	The recipe group that displays the recipe in the recipe explorer gui.
deserializer	RecipeDeserializer<T>?	The deserializer that deserializes the recipe files to an instance of the previously specified recipeClass.

Attention

Setting RecipeGroup to null can lead to exceptions being thrown when players try to view recipes from that type.

Creating a custom Recipe Type

Recipe ClassRecipe DeserializerRecipe Group

Every recipe that is created also creates a new instance of the recipeClass. That object then contains all the information about the recipe (e.g. Input, Output, Time, etc.).

The following example is the PulverizerRecipe from the Machines addon:

PulverizerRecipe

class PulverizerRecipe(
    key: NamespacedKey,
    input: RecipeChoice,
    result: ItemStack,
    time: Int,
) : ConversionNovaRecipe(key, input, result, time) {
    override val type = RecipeTypes.PULVERIZER
}

Since a Pulverizer just converts one input item to another output item, I could use the pre-existing ConversionNovaRecipe. Depending on your recipe type, you might need to directly inherit from NovaRecipe though.

The recipe deserializer deserializes the recipe file to an instance of the recipeClass.

For the PulverizerRecipe from Machines, the recipe deserializer is actually quite easy, as you can just extend the already existing ConversionRecipeDeserializer:

PulverizerRecipeDeserializer

object PulverizerRecipeDeserializer : ConversionRecipeDeserializer<PulverizerRecipe>() {
    override fun createRecipe(json: JsonObject, key: NamespacedKey, input: RecipeChoice, result: ItemStack, time: Int) =
        PulverizerRecipe(key, input, result, time)
}

However, depending on you recipe type you might need to do some more work. The following deserializer is used for the fluid infuser recipe:

FluidInfuserRecipeDeserializer

object FluidInfuserRecipeDeserializer : RecipeDeserializer<FluidInfuserRecipe> {

    override fun deserialize(json: JsonObject, file: File): FluidInfuserRecipe {
        val mode = json.getDeserialized<FluidInfuserRecipe.InfuserMode>("mode")!!
        val fluidType = json.getDeserialized<FluidType>("fluid_type")!!
        val fluidAmount = json.getLong("fluid_amount")!!
        val input = parseRecipeChoice(json.get("input"))
        val time = json.getInt("time")!!
        val result = ItemUtils.getItemBuilder(json.getString("result")!!).get()

        return FluidInfuserRecipe(getRecipeKey(file), mode, fluidType, fluidAmount, input, result, time)
    }

}

Info

Make sure to always use the parseRecipeChoice(JsonElement), ItemUtils.getItemBuilder(String) andgetRecipeKey(File) utility methods instead of using your own logic.

The recipe group is only used for the recipe explorer GUI, so your recipes will already work without it.
However, it is still required to create a recipe group.

As always, it is very easy to create a recipe group for conversion recipes:

PulverizingRecipeGroup

object PulverizingRecipeGroup : ConversionRecipeGroup<PulverizerRecipe>() {
    override val priority = 4 // (1)!
    override val icon = Items.PULVERIZER.model.clientsideProvider // (2)!
    override val texture = GuiTextures.RECIPE_PULVERIZER // (3)!
}

1. The priority defines where in the recipe explorer your recipe type is going to be. (Lower value -> left | Higher value -> right)
2. The icon displayed for your recipe type.
3. The GUI Texture used when displaying your recipe type.

However, if your recipe is not a ConversionNovaRecipe, your recipe group might be a bit more work:
(The resulting GUI needs to be in the dimensions 9x3)

FluidInfuserRecipeGroup

object FluidInfuserRecipeGroup : RecipeGroup<FluidInfuserRecipe>() {

    override val texture = GuiTextures.RECIPE_FLUID_INFUSER
    override val icon = Items.FLUID_INFUSER.model.clientsideProvider
    override val priority = 6

    override fun createGui(recipe: FluidInfuserRecipe): Gui {
        val progressItem: ItemBuilder
        val translate: String
        if (recipe.mode == FluidInfuserRecipe.InfuserMode.INSERT) {
            progressItem = GuiItems.TP_FLUID_PROGRESS_LEFT_RIGHT.model.createClientsideItemBuilder()
            translate = "menu.machines.recipe.insert_fluid"
        } else {
            progressItem = GuiItems.TP_FLUID_PROGRESS_RIGHT_LEFT.model.createClientsideItemBuilder()
            translate = "menu.machines.recipe.extract_fluid"
        }

        progressItem.setDisplayName(Component.translatable(
            translate,
            Component.text(recipe.fluidAmount),
            Component.translatable(recipe.fluidType.localizedName)
        ))

        return Gui.normal()
            .setStructure(
                ". f . t . . . . .",
                ". f p i . . . r .",
                ". f . . . . . . .")
            .addIngredient('i', createRecipeChoiceItem(recipe.input)) // (1)!
            .addIngredient('r', createRecipeChoiceItem(listOf(recipe.result)))
            .addIngredient('p', progressItem)
            .addIngredient('f', StaticFluidBar(3, FLUID_CAPACITY, recipe.fluidType, recipe.fluidAmount))
            .addIngredient('t', DefaultGuiItems.TP_STOPWATCH.model
                .createClientsideItemBuilder()
                .setDisplayName(Component.translatable("menu.nova.recipe.time", Component.text(recipe.time / 20.0)))
            ).build()
    }

}

1. This function creates an InvUI item for a RecipeChoice. When clicked, it shows you recipes / usages for that item. It also automatically cycles through all possible input options if there is more than one.

InvUI Documentation