How to communicate to an inventory item which character it's being used on?

Question

Currently, I have an Inventory that is a ScriptableObject, which means it's not tied to any specific game object or player character. I just drag it into a MonoBehaviour if I would like expose the data of the inventory.

I have created an InventoryUI, which is a MonoBehaviour attached to a GameObject in my scene, and I assign the Inventory SO to it.

The InventoryUI contains button GameObjects with an InventorySlot script, to which I assign the item each slot is holding.

Everything works fine. When I click on one of the InventorySlot buttons, I'm able to call item methods, such as UseItem.

My problem is if the the item is a potion, for example. How can i add health to the player? Of course I could add reference to the player to the slot. But that will reference player repeatedly over 25 slots.

Answer 1

Myself, I'd let the InventoryUI script own the interaction with the inventory.

When a player opens the InventoryUI, you call something like InventoryUI.ShowInventoryFor(PlayerCharacter character).

This procedure handles any initial setup of the menu (populating the slots, etc.) and caches the character it was given as its currentUser member variable.

Each of the UI buttons on the menu is wired up to call InventoryUI.UseItemInSlot(int slotID) when clicked. That centralizes all of the item use actions onto the one script that knows who's using the menu.

Now the InventoryUI can fetch the corresponding item in your inventory structure, and call inventoryItem.UseItemOn(currentUser), passing its knowledge of who is using the item through to the function that performs the item's action.

Finally, that item receives a reference to the character it should modify - by giving it more health, etc.

Doing it this way, you might not need your InventorySlot script at all. The buttons in the menu can be just plain buttons, with the knowledge of the meaning behind each button provided by the InventoryUI itself.