/// <summary>
/// <para>Converts NotificationObject's property to ReactiveProperty. Value is two-way synchronized.</para>
/// <para>PropertyChanged raise on selected scheduler.</para>
/// </summary>
/// <typeparam name="TSubject">The type of the subject.</typeparam>
/// <typeparam name="TProperty">The type of the property.</typeparam>
/// <param name="subject">The subject.</param>
/// <param name="propertySelector">Argument is self, Return is target property.</param>
/// <param name="raiseEventScheduler">The raise event scheduler.</param>
/// <param name="mode">ReactiveProperty mode.</param>
/// <param name="ignoreValidationErrorValue">Ignore validation error value.</param>
/// <returns></returns>
public static ReactiveProperty <TProperty> ToReactivePropertyAsSynchronized <TSubject, TProperty>(
this TSubject subject,
Expression <Func <TSubject, TProperty> > propertySelector,
IScheduler raiseEventScheduler,
ReactivePropertyMode mode = ReactivePropertyMode.DistinctUntilChanged | ReactivePropertyMode.RaiseLatestValueOnSubscribe,
bool ignoreValidationErrorValue = false)
where TSubject : INotifyPropertyChanged
{
var setter = AccessorCache <TSubject> .LookupSet(propertySelector, out _);
var result = subject.ObserveProperty(propertySelector, isPushCurrentValueAtFirst: true)
.ToReactiveProperty(raiseEventScheduler, mode: mode);
result
.Where(_ => !ignoreValidationErrorValue || !result.HasErrors)
.Subscribe(x => setter(subject, x));
return(result);
}
private static IObservable <TProperty> ObserveSimpleProperty <TSubject, TProperty>(
this TSubject subject, Expression <Func <TSubject, TProperty> > propertySelector,
bool isPushCurrentValueAtFirst = true)
where TSubject : INotifyPropertyChanged
{
var isFirst = true;
var accessor = AccessorCache <TSubject> .LookupGet(propertySelector, out var propertyName);
return(Observable.Defer(() =>
{
var flag = isFirst;
isFirst = false;
var q = subject.PropertyChangedAsObservable()
.Where(e => e.PropertyName == propertyName || string.IsNullOrEmpty(e.PropertyName))
.Select(_ => accessor.Invoke(subject));
return (isPushCurrentValueAtFirst && flag) ? q.StartWith(accessor.Invoke(subject)) : q;
}));
}
/// <summary>
/// Converts NotificationObject's property changed to an observable sequence.
/// </summary>
/// <param name="propertySelector">Argument is self, Return is target property.</param>
/// <param name="isPushCurrentValueAtFirst">Push current value on first subscribe.</param>
public static IObservable <TProperty> ObserveProperty <TSubject, TProperty>(
this TSubject subject, Expression <Func <TSubject, TProperty> > propertySelector,
bool isPushCurrentValueAtFirst = true)
where TSubject : INotifyPropertyChanged
{
string propertyName;
var accessor = AccessorCache <TSubject> .LookupGet(propertySelector, out propertyName);
var isFirst = true;
var result = Observable.Defer(() =>
{
var flag = isFirst;
isFirst = false;
var q = subject.PropertyChangedAsObservable()
.Where(e => e.PropertyName == propertyName)
.Select(_ => accessor.Invoke(subject));
return((isPushCurrentValueAtFirst && flag) ? q.StartWith(accessor.Invoke(subject)) : q);
});
return(result);
}
