/*[HttpPost]
* [ValidateAntiForgeryToken]
* public async Task<IActionResult> Wypozycz(int id, [Bind("UserID,Imie,Nazwisko,Zapisany_od,Books")] User user, int[] selectedBooks,string searchString,string currentFilter)
* {
* if (id != user.UserID)
* {
* return NotFound();
* }
* ViewData["CurrentFilter"] = searchString;
* if (searchString==null)
* {
* searchString = currentFilter;
* }
* user = await _context.Users
* .Include(u => u.Books)
* .ThenInclude(b=>b.Autor)
* .AsNoTracking()
* .SingleOrDefaultAsync(m => m.UserID == id);
*
* if (ModelState.IsValid)
* {
* UpdateUserBooks(user, selectedBooks);
* try
* {
* _context.Update(user);
* await _context.SaveChangesAsync();
* }
* catch (DbUpdateConcurrencyException)
* {
* if (!UserExists(user.UserID))
* {
* return NotFound();
* }
* else
* {
* throw;
* }
* }
*
* return RedirectToAction(nameof(Wypozycz));
* }
* PopulateBookDropdownList(searchString);
* return View(user);
* }*/
private void UpdateUserBooks(User userToUpdate, int[] selectedBooks)
{
if (selectedBooks == null)
{
userToUpdate.Books = new List <Book>();
return;
}
var selectedBooksHS = new HashSet <int>(selectedBooks);
var currentBooks = new HashSet <int>
(userToUpdate.Books.Select(b => b.BookID));
foreach (var book in _context.Books.Include(a => a.Autor).AsNoTracking())
{
if (selectedBooksHS.Contains(book.BookID))
{
if (currentBooks.Contains(book.BookID))
{
Book removedBook = userToUpdate.Books.SingleOrDefault(b => b.BookID == book.BookID);
_context.Remove(removedBook);
_context.Books.Add(new Book {
Tytul = book.Tytul, AuthorID = book.AuthorID, Autor = book.Autor, Gatunek = book.Gatunek
});
//userToUpdate.Books.Remove(removedBook);
//_context.Update(removedBook);
}
else
{
userToUpdate.Books.Add(new Book {
BookID = book.BookID, Tytul = book.Tytul, AuthorID = book.AuthorID, Autor = book.Autor, Gatunek = book.Gatunek
});
}
}
}
}
