Using an Attribute

Using an Attribute

Following on from the previous page, Adding an Attribute, we will look at how we would use Max Mana to do some things in-game. Before proceeding, there are some important things to note:

• Our attribute's value is synced to the client every time it changes.
• Our static access point to our attribute MAX_MANA is lazily loaded and is null on the client until the player has joined a world, and is null on the server until the datapack containing the jsons is loaded (obviously).

Accessing Max Mana

void genericMethod(PlayerEntity player) {
    // Cardinal Components data manager
    AttributeData data = ExAPI.DATA.get(player);
    
    // Max Mana's value
    double value = data.get(ExampleMod.MAX_MANA.get());
    
    // We can use this value however we want
    // Note that this value remains consistent across logical sides.
}

Modifying Max Mana

void genericMethod(PlayerEntity player) {
    // Cardinal Components data manager
    AttributeData data = ExAPI.DATA.get(player);
    
    // Adding 4.0 to Max Mana
    data.add(ExampleMod.MAX_MANA.get(), 4.0D);
    
    // Setting Max Mana to 4.0
    data.set(ExampleMod.MAX_MANA.get(), 4.0D);

    // Note that these both trigger Attribute Functions
}

Applying Modifiers to Max Mana

// UUID's should be statically initialised
static UUID MODIFIER = UUID.fromString("d540c322-cd52-46db-8251-65928971151b");

void genericMethod(PlayerEntity player) {
    // Cardinal Components data manager
    AttributeData data = ExAPI.DATA.get(player);
    
    // Creating the EntityAttributeModifier object
    EntityAttributeModifier modifier = new EntityAttributeModifier(MODIFIER, "examplemod.modifier.max_mana", 4.0D, Operation.ADDITION);
    
    // Applying the modifier to Max Mana
    data.applyAttributeModifier(ExampleMod.MAX_MANA.get(), modifier);
    
    // And if we want to remove it
    data.removeAttributeModifier(ExampleMod.MAX_MANA.get(), modifier);
    
    // Note that once the modifier is applied, the only way to remove it is through AttributeData#removeAttributeModifier
}