public IActionResult SaveNewsLetter(NewsLetterViewModel newsLetterVm) { if (!ModelState.IsValid) { return(new OkObjectResult(false)); } if (newsLetterVm.Id != 0) { _newsLetterService.UpdateNewsLetter(newsLetterVm); } else { _newsLetterService.AddNewsLetter(newsLetterVm); } _newsLetterService.Save(); return(new OkObjectResult(true)); }