Player Inventory Changed Event

This code belongs in server scripts.

There are two ways to use inventory-changed events:

1. PlayerEvents.inventoryChanged(itemId, event => {}) captures when a specific item enters player inventory.
2. PlayerEvents.inventoryChanged(event => {}) captures all inventory-change events.

Directly Accessible Methods

Method	Purpose	Return Type	Direct Value
getEntity()	Get the entity whose inventory changed (usually a player)	Entity	entity
getItem()	Get the item that caused the inventory change	ItemStack	item
getLevel()	Get the world where the inventory changed	Level	level
getPlayer()	Get the player whose inventory changed	Player	player
getServer()	Get the relevant server instance	MinecraftServer	server
getSlot()	Get the slot index that changed	number	slot
hasGameStage(String)	Check whether a game stage exists	boolean	-
removeGameStage(String)	Remove a game stage	void	-
addGameStage(String)	Add a game stage	void	-

Example

The example below checks whether the changed item is in a banned list. If it is, the item is removed.

const banItems = [
    'minecraft:nether_star',
    'minecraft:lapis_lazuli',
    'minecraft:emerald',
    'minecraft:copper_ingot'
];

PlayerEvents.inventoryChanged(event=>{
    let item = event.getItem()
    if (undefined != banItems.find(value=> value==item.id)){
        event.getPlayer().getInventory().clear(item)
        event.player.tell("Contraband found: " + item.displayName.getString() + " removed!")
    }  
})

const banItems = [] defines an array of controlled/banned item IDs.

banItems.find(value=> value==item.id) checks whether the item is in that list. If not found, it returns undefined.

So you can determine whether the item is banned by checking whether the result is undefined.

event.getPlayer().getInventory().clear(item) clears that item.

event.player.tell() sends a message to the player telling them the item was removed.