private async void ScannerOnDisappearing(object sender, EventArgs e)
{
const string genericErrorMessage =
"Sorry, an error occurred when adding the book to your library. Try again later.";
var scanner = sender as Scanner;
var result = scanner?.ScanResult;
// try disconnecting the event handler
if (scanner != null)
{
scanner.Disappearing -= ScannerOnDisappearing;
}
if (string.IsNullOrEmpty(result))
{
return;
}
try
{
// notify the user
ToastService.Info($"Scanned ISBN: {result}. Adding to your library.");
// call the service
await _bookService.AddByIsbn(result);
ToastService.Success("Book successfully added to your library");
// refresh the library
await pageHome.LoadData();
await pageLibrary.LoadData();
}
catch (ApiException ex) when(ex.IsValidationException())
{
var error = await ex.GetContentAsAsync <ValidationErrorViewModel>();
ToastService.Error(error?.Message?.Length > 0 ? error.Message[0] : genericErrorMessage);
}
catch (ApiException ex)
{
var error = await ex.GetContentAsAsync <ErrorViewModel>();
ToastService.Error(error?.Message?.Length > 0 ? error.Message : genericErrorMessage);
}
}
protected async void Add(object sender, EventArgs e)
{
const string genericErrorMessage =
"Sorry, an error occurred when adding the book to your library. Try again later.";
var isbn = txtIsbn.Text;
if (string.IsNullOrWhiteSpace(isbn))
{
ToastService.Error("An isbn is required.");
return;
}
stkBtns.IsVisible = false;
prgAdding.IsVisible = true;
try
{
await _bookService.AddByIsbn(isbn);
// notify user
ToastService.Success("Book successfully added to your library.");
// send data back
Dismiss("");
}
catch (ApiException ex) when(ex.IsValidationException())
{
var error = await ex.GetContentAsAsync <ValidationErrorViewModel>();
ToastService.Error(error?.Message?.Length > 0 ? error.Message[0] : genericErrorMessage);
}
catch (ApiException ex)
{
var error = await ex.GetContentAsAsync <ErrorViewModel>();
ToastService.Error(!string.IsNullOrWhiteSpace(error?.Message) ? error.Message : genericErrorMessage);
}
finally
{
stkBtns.IsVisible = true;
prgAdding.IsVisible = false;
}
}
