public async Task <IActionResult> Create(PagesListViewModel model)
        {
            var checkStub = new Regex(@"^[\w\-]*$");

            if (!checkStub.IsMatch(model.PageHeader.Stub))
            {
                ModelState.AddModelError("PageHeader.Stub", "Invalid stub, only letters, numbers, hypens and underscores are allowed");
            }
            if (ModelState.IsValid)
            {
                try
                {
                    var pageHeader = await _pageService.AddPageHeaderAsync(model.PageHeader);

                    ShowAlertSuccess($"Page \"{pageHeader.PageName}\" created!");
                    return(RedirectToAction(nameof(Detail), new { id = pageHeader.Id }));
                }
                catch (GraException gex)
                {
                    AlertInfo = gex.Message;
                }
            }
            else
            {
                var errorMessages = new StringBuilder("<ul>");
                foreach (var error in ModelState.Values.SelectMany(_ => _.Errors))
                {
                    errorMessages.Append("<li>").Append(error.ErrorMessage).Append("</li>");
                }
                errorMessages.Append("</ul>");

                ShowAlertDanger("Could add the page to the following error(s):",
                                errorMessages.ToString());
            }

            return(RedirectToAction(nameof(Index), new { page = model.PaginateModel.CurrentPage }));
        }