Shelf

Overview

This component manages a shelf's item content and availability for interaction: it tracks an item placed on the shelf, controls whether the item can be taken (via cantakeitem), provides callbacks for item placement and removal, and handles the logic for giving or dropping the item to a taker.

Dependencies & Tags

• Dependencies: Relies on inst.components.inventory being present on the same entity for item operations (drop/give).
• Tags: Adds the "takeshelfitem" tag when an item is present and cantakeitem is true. Removes the tag in all other cases or when the component is removed.

Properties

Property	Type	Default Value	Description
inst	Entity	nil	The entity this component is attached to.
cantakeitemfn	function?	nil	Optional test function (not directly used internally but implied to validate item taking).
itemonshelf	PrefabInstance?	nil	The item currently placed on the shelf.
onitemtakenfn	function?	nil	Callback for when an item is taken. (⚠️ Note: In source, this property name is assigned as ontakeitemfn in setter—see usage. This may be a typo in original code.*)
cantakeitem	boolean	false	Flag indicating whether items on the shelf can currently be taken.
onshelfitemfn	function?	nil	Callback invoked when an item is placed on the shelf.
ontakeitemfn	function?	nil	Callback invoked when an item is taken from the shelf.
takeitemtstfn	function?	nil	Optional test function to validate if a specific taker can take the item.

Main Functions

PutItemOnShelf(item)

• Description: Places an item on the shelf. Sets itemonshelf and invokes the optional onshelfitemfn callback. Automatically updates the "takeshelfitem" tag based on current state.
• Parameters:
  • item: The item entity to place on the shelf.

TakeItem(taker)

• Description: Attempts to take the current item from the shelf and transfer it to the taker. Validates that an item is present and cantakeitem is true. Optionally runs takeitemtstfn, then triggers ontakeitemfn, and finally moves the item via inventory logic (give to taker or drop to world).
• Parameters:
  • taker: The entity attempting to take the item (can be nil).
  • Note: If taker has an inventory, the item is given. Otherwise, the item is dropped from the shelf's inventory slot. If validation fails (e.g., takeitemtstfn returns false), the operation aborts.

GetDebugString()

• Description: Returns a debug-friendly string describing the current item on the shelf and whether it is takeable.
• Parameters: None.

SetOnShelfItem(fn)

• Description: Sets the callback function invoked when an item is placed on the shelf.
• Parameters:
  • fn: Function (shelf_inst, item) -> void.

SetOnTakeItem(fn)

• Description: Sets the callback function invoked when an item is taken from the shelf.
• Parameters:
  • fn: Function (shelf_inst, taker, item) -> void.

OnRemoveFromEntity()

• Description: Cleanup function called when the component is removed. Ensures the "takeshelfitem" tag is removed.

Events & Listeners

• Listens for changes to cantakeitem and itemonshelf properties via the shared ontakeshelfitem handler (triggered via metatable __newindex), which updates the "takeshelfitem" tag accordingly.
• No explicit inst:ListenForEvent or inst:PushEvent calls are present in the source.