/// <summary>
/// Initializes a new instance of the <see cref="PropertyReferenceObserverOnValueChangedWithDefer{TResult}" /> class.
/// </summary>
/// <param name="propertyExpression">The property expression.</param>
/// <param name="observerFlag">The observer flag.</param>
/// <exception cref="ArgumentNullException">propertyExpression is null.</exception>
internal PropertyReferenceObserverOnValueChangedWithDefer(
[NotNull] Expression <Func <TResult> > propertyExpression,
PropertyObserverFlag observerFlag)
: base(propertyExpression, observerFlag)
{
propertyExpression = propertyExpression ?? throw new ArgumentNullException(nameof(propertyExpression));
var getter = ExpressionGetter.CreateReferenceGetter <TResult>(propertyExpression.Parameters, this.Tree);
this.deferrer = new UpdateableMultibleDeferrer(() => this.Value = getter());
this.action = () => this.deferrer.Update();
}
/// <summary>
/// Initializes a new instance of the <see cref="PropertyReferenceObserverOnValueChangedWithDefer{TParameter1, TResult}" /> class.
/// </summary>
/// <param name="parameter1">The parameter1.</param>
/// <param name="propertyExpression">The property expression.</param>
/// <param name="taskScheduler">The task scheduler.</param>
/// <param name="observerFlag">The observer flag.</param>
/// <exception cref="ArgumentNullException">propertyExpression is null.</exception>
internal PropertyReferenceObserverOnValueChangedWithDefer(
[NotNull] TParameter1 parameter1,
[NotNull] Expression <Func <TParameter1, TResult> > propertyExpression,
TaskScheduler taskScheduler,
PropertyObserverFlag observerFlag)
: base(parameter1, propertyExpression, observerFlag)
{
propertyExpression = propertyExpression ?? throw new ArgumentNullException(nameof(propertyExpression));
var getter = ExpressionGetter.CreateReferenceGetter <TResult>(propertyExpression.Parameters, this.Tree);
this.deferrer = new UpdateableMultibleDeferrer(
() => new TaskFactory(taskScheduler).StartNew(() => this.Value = getter()).Wait());
this.action = () => this.deferrer.Update();
}