/// <summary>
/// Prefer other overloads with x => x.PropertyName for refactor friendliness.
/// This is faster though.
/// </summary>
/// <param name="source">
/// The source.
/// </param>
/// <param name="name">
/// The name.
/// </param>
/// <param name="signalInitial">
/// If true OnNext is called immediately on subscribe
/// </param>
/// <returns>
/// The <see cref="IObservable"/>.
/// </returns>
public static IObservable <EventPattern <PropertyChangedEventArgs> > ObservePropertyChanged(
this INotifyPropertyChanged source,
string name,
bool signalInitial = true)
{
var observable = source.ObservePropertyChanged()
.Where(e => IsPropertyName(e.EventArgs, name));
if (signalInitial)
{
var wr = new WeakReference(source);
return(Observable.Defer(
() =>
{
var current = new EventPattern <PropertyChangedEventArgs>(wr.Target, new PropertyChangedEventArgs(name));
return Observable.Return(current)
.Concat(observable);
}));
}
else
{
return(observable);
}
}
