Question by PaperMartin1 · Oct 17, 2018 at 10:55 AM · c#inventory inventory system item items

Decorator pattern for inventory item class

Thinking about having items as classes that hold a list of "attributes" like how a gameobject holds component That'd allow for varied items in terms of stats and other stuff, and less trouble regarding initializing/cloning items, also no issues with inheritance Thing is it could cause problem when say, an Item has the same attribute twice with different values Could be fixed by editor scripts but heh Does this sound like a correct implementation of items? Anything I should know?

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ShadyProductions · Oct 17, 2018 at 11:26 AM 0

Why would you need the same attribute twice? That makes no sense.

PaperMartin1 ShadyProductions · Oct 17, 2018 at 11:59 AM 0

I mean, if it's just a list that holds the attribute, one could add one twice. I don't need it, I just don't know how to avoid it by design

ShadyProductions PaperMartin1 · Oct 17, 2018 at 12:12 PM 0

But an 'Item' object can techniqually never have 2 same attributes. The easiest is to create a base class for your items with some basic attributes that each item could have. And then make seperate groups of classes for each type of item. Here's an example.

 public abstract class ItemBase : MonoBehaviour { }
 
 public class Weapon : ItemBase {
 
 }
 
 public class Consumable : ItemBase {
 
 }
 
 public class Manager : MonoBehaviour {
      public ItemBase[] Items; // can contain weapons, consumables etc
 }

Bunny83 · Oct 18, 2018 at 03:16 AM 0

I'm not sure what you're asking here. The decorator pattern does not prevent duplicate decorators either. The decorator pattern is actually rarely used. In most cases you would have a strategy pattern (comparable with components and gameobjects). Is there a reason why an item can't be a gameobject / prefab? What issues do you mean when it comes to cloning? And what issues regarding to inheritance? A decorator creates a chain of classes where the decorator instance replaces the actual instance and wraps it's functionality. Most Linq implementations are decorators or adapters.

How and where do you actually want to define your different items? The creation of items is usually an edit time process unless you want random generated items.

You use the terms "item" and "attribute" in a very abstract way. It could mean almost anything. You should think about your question again and clear up what you actually want to know. Also you may want to get more concrete about your items and attributes. Is an item just the logical representation of an item? Or does it include any visual representation (2d / 3d)?

PaperMartin1 Bunny83 · Oct 18, 2018 at 03:16 PM 0

Basically, I want to be able to either generate an item out of a scriptableobject template or let a script generate its own items itself I don't want to have specific classes for different types of items and instead add different types of stats/other thing to a base item (stuff like perks, different types of stats, etc), which an item would hold in a list

Monobehaviours on gameobjects could work but supposedly lots of gameobjects lead to bad performance and also it could be troubles when it comes to saving them or transfering them between scenes