Last Update: 2023-07-06

Inventory Component

API Version: 619045

The Inventory component manages item storage, equipment slots, and item manipulation for entities that can carry items (such as players and some creatures).

Basic Usage

-- Add an inventory component to an entity
local entity = CreateEntity()
entity:AddComponent("inventory")

-- Configure the inventory component
local inventory = entity.components.inventory
inventory.maxslots = 16 -- Set maximum inventory slots

Properties

Property	Type	Description
maxslots	Number	Maximum number of item slots in the inventory
itemslots	Table	Table of items currently in inventory slots
equipslots	Table	Table of items currently equipped in equipment slots
activeitem	Entity	The currently active item (being held/manipulated)
acceptsstacks	Boolean	Whether inventory accepts stacked items
heavylifting	Boolean	Whether the entity is currently carrying a heavy object
isopen	Boolean	Whether the inventory UI is open
isvisible	Boolean	Whether the inventory is visible
dropondeath	Boolean	Whether items are dropped on death

Key Methods

Basic Inventory Operations

-- Give an item to the inventory
inventory:GiveItem(item)

-- Get an item by slot number
local item = inventory:GetItemInSlot(1)

-- Get the slot number of a specific item
local slot = inventory:GetItemSlot(item)

-- Remove an item from a specific slot
local item = inventory:RemoveItemBySlot(1)

-- Check if inventory is full
local is_full = inventory:IsFull()

-- Count items in inventory
local count = inventory:NumItems()

-- Count all items including stacked items
local total = inventory:NumStackedItems()

-- Drop everything in the inventory
inventory:DropEverything(drop_active_item)

Equipment Management

-- Equip an item
inventory:Equip(item)

-- Unequip an item from a specific slot
local item = inventory:Unequip(EQUIPSLOTS.HANDS)

-- Check if a slot has an item equipped
local is_equipped = inventory:IsEquipped(item)

-- Get item in a specific equipment slot
local weapon = inventory:GetEquippedItem(EQUIPSLOTS.HANDS)

Related functions: When equipping an item with the Equip() function, inventory calls the Equippable Component's OnEquip() method, which triggers visual changes and functional effects. Weapons equipped this way are automatically registered with the entity's Combat Component, and armor items apply their protection effects through the damage calculation system.

Active Item Management

-- Set the active item
inventory:GiveActiveItem(item)

-- Get the currently active item
local active_item = inventory:GetActiveItem()

-- Drop the active item
local item = inventory:DropActiveItem()

-- Check if an item is the active item
local is_active = inventory:IsActiveItem(item)

Item Finding

-- Find an item by prefab name
local berries = inventory:FindItem(function(item) return item.prefab == "berries" end)

-- Count items by prefab
local count = inventory:CountItems("log")

-- Check if has at least one of an item
local has_item = inventory:Has("flint", 1)

Containers

-- Open a container
inventory:OpenContainer(container)

-- Close a container
inventory:CloseContainer(container)

-- Check if a container is open
local is_open = inventory:IsContainerOpen(container)

Events

The Inventory component responds to and triggers various events:

• itemget - Triggered when an item is added to the inventory
• itemlose - Triggered when an item is removed from the inventory
• equip - Triggered when an item is equipped
• unequip - Triggered when an item is unequipped
• activeitem - Triggered when the active item changes
• death - Listens for death to drop items (if dropondeath is true)

Integration with Other Components

The Inventory component often works with:

• ItemSlot - For managing item slots and organization
• Container - For storing items in containers like chests
• Equippable - For items that can be equipped
• Combat - For equipping weapons
• Health - For using healing items

See also

• Container Component - For storing items in containers
• Equippable Component - For items that can be equipped
• Combat Component - For using weapons from inventory
• Builder Component - For crafting items from inventory resources
• Stackable Component - For stacking items in inventory

Examples

-- Create a basic entity with inventory
local function MakeInventoryEntity()
    local inst = CreateEntity()
    
    -- Add required components
    inst:AddComponent("inventory")
    
    -- Configure inventory
    local inventory = inst.components.inventory
    inventory.maxslots = 20
    
    -- Add callback for when items are added
    inst:ListenForEvent("itemget", function(inst, data)
        print("Got item:", data.item.prefab)
    end)
    
    return inst
end

-- Example of using inventory to craft an item
local function CraftItem(inventory, recipe)
    -- Check if inventory has all ingredients
    local has_ingredients = true
    for _, ingredient in ipairs(recipe.ingredients) do
        if not inventory:Has(ingredient.type, ingredient.amount) then
            has_ingredients = false
            break
        end
    end
    
    if has_ingredients then
        -- Remove ingredients
        for _, ingredient in ipairs(recipe.ingredients) do
            for i = 1, ingredient.amount do
                local item = inventory:FindItem(function(item) 
                    return item.prefab == ingredient.type 
                end)
                inventory:RemoveItem(item, true)
            end
        end
        
        -- Give crafted item
        local crafted_item = SpawnPrefab(recipe.product)
        inventory:GiveItem(crafted_item)
        return true
    end
    
    return false
end