Snootalogue/Pages/Documents/Edit.cshtml.cs

using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using Microsoft.EntityFrameworkCore;
using Snootalogue.Data;
using Snootalogue.Models;
using Snootalogue.ViewModels;

namespace Snootalogue.Pages.Documents {
	public class EditModel : PageModel {
		private readonly SnootalogueContext _context;
		[BindProperty]
		public EditDocument ed { get; set; }

		public EditModel(SnootalogueContext context) {
			_context = context;
		}

		public async Task<IActionResult> OnGetAsync(string id) {
			if (id == null) {
				return NotFound();
			}

			var Document = await _context.Document.FirstOrDefaultAsync(d => d.ID == id);

			if (Document == null) {
				return NotFound();
			}

			ed = new EditDocument {
				ID = Document.ID,
				Title = Document.Title,
				Authors = string.Join(",", Document.Authors),
				Category = Document.Category,
				Tags = Document.Tags == null ? "" : string.Join(",", Document.Tags),
				Read = Document.Read
			};

			return Page();
		}

		public async Task<IActionResult> OnPostAsync() {
			if (!ModelState.IsValid) {
				return Page();
			}

			Document d = _context.Document.First(d => d.ID == ed.ID);
			d.Title = ed.Title;
			d.Authors = ed.Authors.Split(",").ToList<string>();
			d.Category = ed.Category;
			d.Tags = string.IsNullOrWhiteSpace(ed.Tags) ? null : ed.Tags.Split(",").ToList<string>();
			d.Notes = ed.Notes;
			d.Read = ed.Read;

			_context.Attach(d).State = EntityState.Modified;

			try {
				await _context.SaveChangesAsync();
			}
			catch (DbUpdateConcurrencyException e) {
				// TODO: handle it like https://github.com/dotnet/AspNetCore.Docs/blob/master/aspnetcore/tutorials/razor-pages/razor-pages-start/sample/RazorPagesMovie30/Pages/Movies/Edit.cshtml.cs#L56
				throw e;
			}

			return RedirectToPage("/Index");
		}
	}
}