public Task<Book> UpdateAsync(Book item)
{
Book bookToUpdate = _books.Find(b => b.BookId == item.BookId);
int ix = _books.IndexOf(bookToUpdate);
_books[ix] = item;
return Task.FromResult(_books[ix]);
}
public MainPage()
{
this.InitializeComponent();
_theBook = new BooksService().GetTheBook();
_books = new ObservableCollection<Book>(new BooksService().GetBooks());
// this.DataContext = this;
}
private void LoadBook(object sender, BookInfoEvent bookInfo)
{
if (bookInfo.BookId == 0)
{
int bookId = _booksService.Books.Select(b => b.BookId).Max() + 1;
Book = new Book(bookId);
}
else
{
Book = _booksService.GetBook(bookInfo.BookId);
}
}
private async void OnSaveBook()
{
try
{
Book book = await _booksService.AddOrUpdateBookAsync(Book);
Book = book;
}
catch (ArgumentNullException ex)
{
MessageBox.Show(ex.Message);
}
}
// TODO: 05 - await in catch
private async void OnSaveBook()
{
try
{
Book book = await _booksService.AddOrUpdateBookAsync(Book);
Book = book;
}
catch (ArgumentNullException)
{
var dlg = new MessageDialog("Add vor Speichern");
await dlg.ShowAsync();
}
}
public void SpecialSave(Book book)
{
if (book.Title.StartsWith("99"))
{
throw new TitleException("Bad title") { MyErrorCode = 99 };
}
else if (book.Title.Length == 5)
{
throw new TitleException("invalid title length") { MyErrorCode = 5 };
}
else if (book.Publisher.StartsWith("42"))
{
throw new PublisherException("bad publisher") { MyErrorCode = 11 };
}
}
// TODO: nameof operator
public async Task<Book> AddOrUpdateBookAsync(Book book)
{
if (book == null) throw new ArgumentNullException("book");
Book old = _books.Where(b => b.BookId == book.BookId).SingleOrDefault();
if (old == null)
{
Book added = await _booksRepository.AddAsync(book);
_books.Add(added);
return added;
}
else
{
Book updated = await _booksRepository.UpdateAsync(book);
int ix = _books.IndexOf(old);
_books.RemoveAt(ix);
_books.Insert(ix, updated);
return updated;
}
}
// TODO: 05 - await in catch
private async void OnSaveBook()
{
bool hasError = false;
string errorMessage = string.Empty;
try
{
Book book = await _booksService.AddOrUpdateBookAsync(Book);
Book = book;
}
catch (ArgumentNullException)
{
hasError = true;
errorMessage = "Add vor Speichern";
}
if (hasError)
{
var dlg = new MessageDialog(errorMessage);
await dlg.ShowAsync();
}
}
public Task<Book> AddAsync(Book item)
{
_books.Add(item);
return Task.FromResult(item);
}