Built-In Data Maps
NeoForge provides various built-in data maps for common use cases, replacing hardcoded vanilla fields. Vanilla values are shipped by data map files in NeoForge, so there is no functional difference to the player.
neoforge:compostables
Allows configuring composter values, as a replacement for ComposterBlock.COMPOSTABLES (which is now ignored). This data map is located at neoforge/data_maps/item/compostables.json and its objects have the following structure:
{
  // A 0 to 1 (inclusive) float representing the chance that the item will update the level of the composter
  "chance": 1
}
Example:
{
  "values": {
    // Give acacia logs a 50% chance that they will fill a composter
    "minecraft:acacia_log": {
      "chance": 0.5
    }
  }
}
neoforge:furnace_fuels
Allows configuring item burn times. This data map is located at neoforge/data_maps/item/furnace_fuels.json and its objects have the following structure:
{
  // A positive integer representing the item's burn time in ticks
  "burn_time": 1000
}
Example:
{
  "values": {
    // Give anvils a 2 seconds burn time
    "minecraft:anvil": {
      "burn_time": 40
    }
  }
}
NeoForge additionally adds the IItemExtension#getBurnTime method to be overridden in custom items, overruling this data map. #getBurnTime should only be used in scenarios where the datamap does not suffice, for example data component-dependent burn times.
Vanilla adds an implicit burn time of 300 ticks (15 seconds) for #minecraft:logs and #minecraft:planks, and then hardcodes the removal of crimson and warped items from that. This means that if you add another non-flammable wood, you should add a removal for that wood type's items from this map, like so:
{
  "replace": false,
  "values": [
    // values here
  ],
  "remove": [
    "examplemod:example_nether_wood_planks",
    "#examplemod:example_nether_wood_stems",
    "examplemod:example_nether_wood_door",
    // etc.
    // other removals here
  ]
}
neoforge:monster_room_mobs
Allows configuring the mobs that may appear in the mob spawner in a monster room, as a replacement for MonsterRoomFeature#MOBS (which is now ignored). This data map is located at neoforge/data_maps/entity_type/monster_room_mobs.json and its objects have the following structure:
{
  // The weight of this mob, relative to other mobs in the datamap
  "weight": 100
}
Example:
{
  "values": {
    // Make squids appear in monster room spawners with a weight of 100
    "minecraft:squid": {
      "weight": 100
    }
  }
}
neoforge:parrot_imitations
Allows configuring the sounds produced by parrots when they want to imitate a mob, as a replacement for Parrot#MOB_SOUND_MAP (which is now ignored). This data map is located at neoforge/data_maps/entity_type/parrot_imitations.json and its objects have the following structure:
{
  // The ID of the sound that parrots will produce when imitating the mob
  "sound": "minecraft:entity.parrot.imitate.creeper"
}
Example:
{
  "values": {
    // Make parrots produce the ambient cave sound when imitating allays
    "minecraft:allay": {
      "sound": "minecraft:ambient.cave"
    }
  }
}
neoforge:raid_hero_gifts
Allows configuring the gift that a villager with a certain VillagerProfession may gift you if you stop the raid, as a replacement for GiveGiftToHero#GIFTS (which is now ignored). This data map is located at neoforge/data_maps/villager_profession/raid_hero_gifts.json and its objects have the following structure:
{
  // The ID of the loot table that a villager profession will hand out after a raid
  "loot_table": "minecraft:gameplay/hero_of_the_village/armorer_gift"
}
Example:
{
  "values": {
    "minecraft:armorer": {
      // Make armorers give the raid hero the armorer gift loot table
      "loot_table": "minecraft:gameplay/hero_of_the_village/armorer_gift"
    },
  }
}
neoforge:vibration_frequencies
Allows configuring the sculk vibration frequencies emitted by game events, as a replacement for VibrationSystem#VIBRATION_FREQUENCY_FOR_EVENT (which is now ignored). This data map is located at neoforge/data_maps/game_event/vibration_frequencies.json and its objects have the following structure:
{
  // An integer between 1 and 15 (inclusive) that indicates the vibration frequency of the event
  "frequency": 2
}
Example:
{
  "values": {
    // Make the splash in water game event vibrate on the second frequency
    "minecraft:splash": {
      "frequency": 2
    }
  }
}