public ItemsViewModel()
{
UserID = -1;
Title = "Browse";
Jokes = new ObservableRangeCollection <Joke>();
LoadItemsCommand = new Command(async() => await ExecuteLoadItemsCommand());
MessagingCenter.Subscribe <NewItemPage, Joke>(this, "AddJoke", async(obj, item) =>
{
var _item = item as Joke;
var newJokes = new List <Joke>();
newJokes.Add(item);
Jokes.AddRange(newJokes);
await JokeInitializer.AddItemAsync(_item);
});
MessagingCenter.Subscribe <ItemDetailPage, Joke>(this, "DeleteJoke", async(obj, item) =>
{
var _item = item as Joke;
//Jokes.Add(_item);
var jokeToDelete = new List <Joke>();
foreach (var el in Jokes)
{
if (el.JokeID == _item.JokeID)
{
jokeToDelete.Add(el);
break;
}
}
Jokes.RemoveRange(jokeToDelete);
await JokeInitializer.DeleteItemAsync(_item);
});
}
async Task ExecuteLoadItemsCommand()
{
if (IsBusy)
{
return;
}
IsBusy = true;
try
{
if (UserID > 0)
{
Jokes.Clear();
var jokes = await JokeInitializer.GetItemsAsync(true, UserID);
Jokes.ReplaceRange(jokes);
}
else
{
Jokes.Clear();
var jokes = await JokeInitializer.GetItemsAsync(true);
Jokes.ReplaceRange(jokes);
}
}
catch (Exception ex)
{
Debug.WriteLine(ex);
MessagingCenter.Send(new MessagingCenterAlert
{
Title = "Error",
Message = "Unable to load items.",
Cancel = "OK"
}, "message");
}
finally
{
IsBusy = false;
}
}
