/// <summary>
/// Listens to the changed properties and merge the event to a sequence.
/// </summary>
/// <typeparam name="TModel">The type of the source model.</typeparam>
/// <typeparam name="TValue">The type of the source value.</typeparam>
/// <param name="source">The source model.</param>
/// <param name="property">The properties expressions.</param>
/// <returns>Event sequence</returns>
public static ObservableWithModel <TModel> Listen <TModel, TValue>(this TModel source,
Expression <Func <TModel, TValue> > property
) where TModel : BindableBase <TModel>
{
var value = source.GetValueContainer(property).Value;
var rval = new ObservableWithModel <TModel>(
source,
source
.GetValueContainer(property)
.GetEventObservable()
.Select(y =>
y.EventArgs)
.StartWith(
new ValueChangedEventArgs <TValue>(property.Name, default(TValue), value)));
return(rval);
}
/// <summary>
///
/// </summary>
/// <typeparam name="TModel"></typeparam>
/// <typeparam name="TValue"></typeparam>
/// <param name="sourceOb"></param>
/// <param name="property"></param>
/// <returns></returns>
public static ObservableWithModel <TModel, IDictionary <string, ValueChangedEventArgs> > Also <TModel, TValue>(this ObservableWithModel <TModel> sourceOb,
Expression <Func <TModel, TValue> > property
) where TModel : BindableBase <TModel>
{
var source = sourceOb.Model;
var value = source.GetValueContainer(property).Value;
var seq1 = sourceOb;
var seq2 = source
.GetValueContainer(property)
.GetEventObservable()
.Select(y =>
y.EventArgs)
.StartWith(
new ValueChangedEventArgs <TValue>(property.Name, default(TValue), value));
var newseq = seq1.Zip(
seq2,
(i1, i2) => new Dictionary <string, ValueChangedEventArgs>()
{
{ i1.PropertyName, i1 },
{ i2.PropertyName, i2 }
});
return(new ObservableWithModel <TModel, IDictionary <string, ValueChangedEventArgs> >(
source,
newseq
));
}
