Building an invetory

Questions & Answers
1

Hello, I’m trying to build my own inventory system, and I need to know how can I create “Item type”… That I attach script on item prefab and selec item type (weapon, clothes, consumable, etc…) and when I select weapon, then I must set weapon damage, weapon type (sword, mace, etc…) weapon lenght… Help me please, how to do that. Should I use enum?

2

It’s a rather generic question, so there’s really no way to give a specific answer…

Use a dictionary type list for storing what objects are in the inventory. You should derive all items from a common item baseclass that implements whatever functions you need for items, like selecting them (equipping a weapon, drinking a potion etc.). The actual item classes can be more diverse and implement the functionality each item should hold, like a weapon’s damage or a potion’s effect.

It would look something like this:

class Inventory {
    // store item type and how many there are
    var inventory : Dictionary.<ItemBase,int> = new Dictionary.<Item_Base,int>();
    // adding an item to the inventory
    function addItem( item : ItemBase ) {
        if ( inventory.ContainsKey( item ) )
            inventory[item] += 1;
        else
            inventory.Add(item ,1);
    }
    // remove and select functions
    // generic inventory functions: sort, filter, etc.
}

Base Class for all items that implements basic inventory access function interfaces.

class ItemBase {
    var owner : CarrierEntity; // class for entities with an inventory - probably the player
    function InventoryAdd {
        CarrierEntity.GetComponent.<Inventory>.addItem(this);
        // keyword 'this' will automatically transform to the class of the child classes when called by them
    }
    function inventoryUse {
        // like above ...
    }
    // more functions common to all items
}

Class for a potion item:

class ItemHealthPotion extends ItemBase {
    // inherits functions InventoryAdd, inventoryUse, ... from base class
    // add code specific to potions here
    var healing : int;
    var delay: float;
    // ...
}

This last one is the class you’d actually apply to a prefab.

€dit:
Thinking about it, it’d be a more generic/robust implementation to index the inventory by prefab instead of script class.