26.1.2 Dynamic Modded Item Registration

Dynamic Modded Item Registration (26.1.2)

System Parameter	Value
Trigger Point	MappedRegistry.freeze() (Registries.ITEM)
Mixin Hook	MappedRegistryMixin
Scanner Class	DurabilityRules.registerDynamicRulesOnRegistryFreeze()
Reflection Target	BuiltInRegistries.DATA_COMPONENT_INITIALIZERS
Dynamic Item List	DurabilityRules.DYNAMIC_ITEMS
Generated Multiplier Key	ig:multiplier_<namespace>_<path>
Generated Infinity Key	ig:infinity_<namespace>_<path>

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⚡ Overview & Purpose

Many Minecraft mods introduce custom weapons, magical wands, energy tools, or mechanical devices that do not use standard vanilla item classes (PickaxeItem, SwordItem) or tags (#minecraft:swords).

Durability Multiplier automatically detects these items and dynamically generates dedicated GameRules for each uncategorized modded item at server startup, allowing full multiplier and God Mode configuration.

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🔧 How the Scanner Works

sequenceDiagram
    participant MR as MappedRegistry (ITEM)
    participant MX as MappedRegistryMixin
    participant DR as DurabilityRules
    participant DCI as DATA_COMPONENT_INITIALIZERS
    participant DGM as DynamicGameRuleManager

    MR->>MX: freeze() called
    MX->>DR: registerDynamicRulesOnRegistryFreeze()
    loop For each Item in BuiltInRegistries.ITEM
        DR->>DR: Skip if namespace is "minecraft" or "c"
        DR->>DCI: Reflection scan initializers for Item ID
        alt Item has MAX_DAMAGE > 0 and uncategorized
            DR->>DGM: Register ig:multiplier_<ns>_<path>
            DR->>DGM: Register ig:infinity_<ns>_<path>
            DR->>DR: Add ID to DYNAMIC_ITEMS list
        end
    end

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Reflection-Based Initializer Inspection

To avoid triggering early component binding errors or NullPointerException: Components not bound yet during mod initialization, DurabilityRules inspects BuiltInRegistries.DATA_COMPONENT_INITIALIZERS using reflection:

1. Accesses initializers list in DATA_COMPONENT_INITIALIZERS.
2. Locates matching ResourceKey<Item>.
3. Runs the initializer against an isolated DataComponentMap.Builder.
4. Checks if DataComponents.MAX_DAMAGE is present and $> 0$.
5. Confirms the item does not have DataComponents.TOOL or DataComponents.EQUIPPABLE (which are already handled in standard categories).

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🎮 In-Game Usage of Dynamic Rules

When an uncategorized modded item (e.g. techmod:plasma_cutter) is detected:

• Multiplier Rule registered: /gamerule ig:multiplier_techmod_plasma_cutter <value>
• God Mode Rule registered: /gamerule ig:infinity_techmod_plasma_cutter <true|false>
• The Cloth Config / ModMenu configuration screen automatically populates these under the Modded Items tab.