`csharp

using UnityEngine;

namespace Gyvr.Mythril2D
{
    [ExecuteInEditMode]
    public class YourClass:MonoBehaviour
    {
        [SerializeField] private string m_gameFlagID = "";

        // Only generate the flagId if it's empty or null
        private void OnValidate()
        {
            // Get the current date and time in the format yymmddhhmmss
            if(m_gameFlagID.IsNullOrEmpty())
              m_gameFlagID = "CLASS_NAME_OR_SOMETHING_CLEAR" + System.DateTime.Now.ToString("yyMMddHHmmss");
            // Make the flagId persist by marking the object as dirty
            UnityEditor.EditorUtility.SetDirty(this);
        }
    }
}