WorkFlow/WorkFlow.API/Controllers/ControllerExtensions.cs

using Microsoft.AspNetCore.Mvc;
using System.Security.Claims;
using WorkFlow.API.Attributes;

namespace WorkFlow.API.Controllers
{
    [APIKeyAuth]
    public static class ControllerExtensions
    {
        public static bool TryGetUserId(this ControllerBase controller, out int? id)
        {
            var value = controller.User.FindFirstValue(ClaimTypes.NameIdentifier);

            if (value is null)
            {
                id = default;
                return false;
            }

            if(int.TryParse(value, out int id_int))
            {
                id = id_int;
                return true;
            }
            else
            {
                id = null;
                return false;
            }
        }

        public static bool TryGetUsername(this ControllerBase controller, out string username)
        {
            var value = controller.User.FindFirstValue(ClaimTypes.Name);

            if (value is null)
            {
                username = string.Empty;
                return false;
            }
            else
            {
                username = value;
                return true;
            }
        }

        public static bool TryGetName(this ControllerBase controller, out string name)
        {
            var value = controller.User.FindFirstValue(ClaimTypes.Surname);

            if (value is null)
            {
                name = string.Empty;
                return false;
            }
            else
            {
                name = value;
                return true;
            }
        }

        public static bool TryGetPrename(this ControllerBase controller, out string prename)
        {
            var value = controller.User.FindFirstValue(ClaimTypes.GivenName);

            if (value is null)
            {
                prename = string.Empty;
                return false;
            }
            else
            {
                prename = value;
                return true;
            }
        }

        public static bool TryGetEmail(this ControllerBase controller, out string email)
        {
            var value = controller.User.FindFirstValue(ClaimTypes.Email);

            if (value is null)
            {
                email = string.Empty;
                return false;
            }
            else
            {
                email = value;
                return true;
            }
        }
    }
}