SingletonScriptable

SingletonScriptable.cs

using System.Linq;
using UnityEditor;
using UnityEngine;

public abstract class SingletonScriptable<T> : ScriptableObject where T : ScriptableObject 
{
    static T _instance = null;
    public static T instance
    {
        get
        {
            if (!_instance)
            {
                _instance = Resources.FindObjectsOfTypeAll<T>().FirstOrDefault();
                if (!_instance)
                {
                    string resourceName = typeof(T).ToString();
                    AssetDatabase.CreateAsset(CreateInstance<T>(), $"Assets/Resources/{resourceName}.asset");
                    _instance = Resources.FindObjectsOfTypeAll<T>().FirstOrDefault();
                }
            }

            return _instance;
        }
    }
}