Should a setter return immediately if assigned the same value?
- by Andrei Rinea
In classes that implement INotifyPropertyChanged I often see this pattern :
public string FirstName
{
get { return _customer.FirstName; }
set
{
if (value == _customer.FirstName)
return;
_customer.FirstName = value;
base.OnPropertyChanged("FirstName");
}
}
Precisely the lines
if (value == _customer.FirstName)
return;
are bothering me. I've often did this but I am not that sure it's needed nor good. After all if a caller assigns the very same value I don't want to reassign the field and, especially, notify my subscribers that the property has changed when, semantically it didn't.
Except saving some CPU/RAM/etc by freeing the UI from updating something that will probably look the same on the screen/whatever_medium what do we obtain?
Could some people force a refresh by reassigning the same value on a property (NOT THAT THIS WOULD BE A GOOD PRACTICE HOWEVER)?
1. Should we do it or shouldn't we?
2. Why?
