Itemweigher

Overview

The ItemWeigher component enables an entity (typically a scale in the game, such as the Trophy Scale) to associate a trophy scale type (e.g., "small", "medium", "large") via dynamic tagging, and to support custom weighing behavior via a user-defined function. It is used primarily by scale entities to determine what trophy tier an item belongs to upon being weighed.

Dependencies & Tags

• Tags managed internally: Adds or removes "trophyscale_<type>" tags on the entity when type is set or changed (e.g., "trophyscale_large").
• No external component dependencies are declared or implied in this script.

Properties

Property	Type	Default Value	Description
inst	Entity	(constructor arg)	Reference to the entity the component is attached to.
type	string?	nil	The current trophy scale type; nil means no type assigned (no tag applied).
ondoweighinfn	function?	nil	Optional callback function invoked when DoWeighIn() is called; receives (scale_inst, target_inst, doer_inst) as arguments.

Note: The type property is not stored as a direct member on self in _ctor, but the class defines type = ontype in the metatable, which redirects assignments to the ondype function. This makes itemweigher.type = "large" trigger the ontype function, which handles tagging.

Main Functions

SetOnDoWeighInFn(fn)

• Description: Sets the callback function that will be executed when DoWeighIn() is invoked. This allows external code (e.g., the scale’s interaction logic) to define custom weighing behavior.
• Parameters:
  • fn (function) — A callable function expecting three arguments: (scale_inst, target_inst, doer_inst), where:
    • scale_inst is the scale entity,
    • target_inst is the item being weighed,
    • doer_inst is the player or entity performing the weigh-in.

DoWeighIn(target, doer)

• Description: Executes the stored weighing callback function, if one is set. Returns the result of the callback or nil if no callback is assigned.
• Parameters:
  • target (Entity) — The item or entity being weighed.
  • doer (Entity) — The entity performing the weigh-in action (typically a player).

Events & Listeners

• Listens for internal property assignment via the type setter, which triggers ontype(self, type, old_type).
• When type is set:
  • If old_type is non-nil, removes tag "trophyscale_"..old_type.
  • If new type is non-nil, adds tag "trophyscale_"..type.
• No external event listeners (e.g., ListenForEvent) are registered in this component.
• The OnRemoveFromEntity() hook sets type = nil on removal to clear any associated tag.