//constructor
public StrengthExerciseViewModel()
{
Title = "Exercises";
//data store
Exercises = new ObservableCollection <StrengthExercise>();
//set commands
LoadExercisesCommand = new Command(async() => await ExecuteLoadItemsCommand());
//default to today
SelectedDate = DateTime.Today;
//define messages this view model can receive
MessagingCenter.Subscribe <NewStrengthExercisePage, StrengthExercise>(this, "AddExercise", async(obj, item) =>
{
//add to source data
await DataStore.AddExerciseAsync(item);
});
MessagingCenter.Subscribe <StrengthExerciseDetailPage, StrengthExercise>(this, "DeleteExercise", async(obj, item) =>
{
//remove from the local data store
Exercises.Remove(Exercises.FirstOrDefault(s => s.Id == item.Id));
//remove from source data
await DataStore.DeleteExerciseAsync(item.Id);
});
MessagingCenter.Subscribe <StrengthExerciseDetailPage, StrengthExercise>(this, "UpdateExercise", async(obj, item) =>
{
if (IsBusy)
{
return;
}
IsBusy = true;
try
{
//update the source data
await DataStore.UpdateExerciseAsync(item);
}
catch (Exception ex)
{
Debug.WriteLine(ex);
}
finally
{
IsBusy = false;
}
});
}
