Package net.neoforged.neoforge.event

Class ItemAttributeModifierEvent

java.lang.Object

net.neoforged.bus.api.Event

net.neoforged.neoforge.event.ItemAttributeModifierEvent

public class ItemAttributeModifierEvent
extends net.neoforged.bus.api.Event

This event is fired when the attributes for an ItemStack are being calculated. Attributes are calculated on the server when equipping and unequipping an item to add and remove attributes respectively, both must be consistent. Attributes are calculated on the client when rendering an item's tooltip to show relevant attributes.
Note that this event is fired regardless of if the stack has NBT overriding attributes or not. If your attribute should be ignored when attributes are overridden, you can check for the presence of the AttributeModifiers tag.
This event is fired on the NeoForge.EVENT_BUS.

Field Summary

Fields

Modifier and Type	Field	Description
private @Nullable com.google.common.collect.Multimap<Holder<Attribute>,AttributeModifier>	modifiableModifiers
private final com.google.common.collect.Multimap<Holder<Attribute>,AttributeModifier>	originalModifiers
private final EquipmentSlot	slotType
private final ItemStack	stack
private com.google.common.collect.Multimap<Holder<Attribute>,AttributeModifier>	unmodifiableModifiers

Constructor Summary

Constructors

Constructor	Description
ItemAttributeModifierEvent(ItemStack stack, EquipmentSlot slotType, com.google.common.collect.Multimap<Holder<Attribute>,AttributeModifier> modifiers)

Method Summary

Modifier and Type	Method	Description
boolean	addModifier(Holder<Attribute> attribute, AttributeModifier modifier)	Adds a new attribute modifier to the given stack.
void	clearModifiers()	Removes all modifiers for all attributes
ItemStack	getItemStack()	Gets the item stack instance
private com.google.common.collect.Multimap<Holder<Attribute>,AttributeModifier>	getModifiableMap()	Gets a modifiable map instance, creating it if the current map is currently unmodifiable
com.google.common.collect.Multimap<Holder<Attribute>,AttributeModifier>	getModifiers()	Returns an unmodifiable view of the attribute multimap.
com.google.common.collect.Multimap<Holder<Attribute>,AttributeModifier>	getOriginalModifiers()	Returns the attribute map before any changes from other event listeners was made.
EquipmentSlot	getSlotType()	Gets the slot containing this stack
Collection<AttributeModifier>	removeAttribute(Holder<Attribute> attribute)	Removes all modifiers for the given attribute
boolean	removeModifier(Holder<Attribute> attribute, AttributeModifier modifier)	Removes a single modifier for the given attribute

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

stack

private final ItemStack stack

slotType

private final EquipmentSlot slotType

originalModifiers

private final com.google.common.collect.Multimap<Holder<Attribute>,AttributeModifier> originalModifiers

unmodifiableModifiers

private com.google.common.collect.Multimap<Holder<Attribute>,AttributeModifier> unmodifiableModifiers

modifiableModifiers

@Nullable
private @Nullable com.google.common.collect.Multimap<Holder<Attribute>,AttributeModifier> modifiableModifiers

Constructor Details

ItemAttributeModifierEvent

public ItemAttributeModifierEvent(ItemStack stack,
 EquipmentSlot slotType,
 com.google.common.collect.Multimap<Holder<Attribute>,AttributeModifier> modifiers)

Method Details

getModifiers

public com.google.common.collect.Multimap<Holder<Attribute>,AttributeModifier> getModifiers()

Returns an unmodifiable view of the attribute multimap. Use other methods from this event to modify the attributes map. Note that adding attributes based on existing attributes may lead to inconsistent results between the tooltip (client) and the actual attributes (server) if the listener order is different. Using getOriginalModifiers() instead will give more consistent results.

getOriginalModifiers

public com.google.common.collect.Multimap<Holder<Attribute>,AttributeModifier> getOriginalModifiers()

Returns the attribute map before any changes from other event listeners was made.

getModifiableMap

private com.google.common.collect.Multimap<Holder<Attribute>,AttributeModifier> getModifiableMap()

Gets a modifiable map instance, creating it if the current map is currently unmodifiable

addModifier

public boolean addModifier(Holder<Attribute> attribute,
 AttributeModifier modifier)

Adds a new attribute modifier to the given stack. Modifier must have a consistent UUID for consistency between equipping and unequipping items. Modifier name should clearly identify the mod that added the modifier.

Parameters:

attribute - Attribute

modifier - Modifier instance.

Returns:

True if the attribute was added, false if it was already present

removeModifier

public boolean removeModifier(Holder<Attribute> attribute,
 AttributeModifier modifier)

Removes a single modifier for the given attribute

Parameters:

attribute - Attribute

modifier - Modifier instance

Returns:

True if an attribute was removed, false if no change

removeAttribute

public Collection<AttributeModifier> removeAttribute(Holder<Attribute> attribute)

Removes all modifiers for the given attribute

Parameters:

attribute - Attribute

Returns:

Collection of removed modifiers

clearModifiers

public void clearModifiers()

Removes all modifiers for all attributes

getSlotType

public EquipmentSlot getSlotType()

Gets the slot containing this stack

getItemStack

public ItemStack getItemStack()

Gets the item stack instance