///-------------------------------------------------------------------------------------------------
/// <summary>
/// Sets calculated property source.
/// </summary>
/// <param name="propertyName">
/// (Optional) Name of the property.
/// </param>
///-------------------------------------------------------------------------------------------------
protected void SetCalculatedPropertySource([CallerMemberName] string propertyName = null)
{
var domain = this.DomainModel; // Check domain model
var tracker = Session.Current as ISupportsCalculatedPropertiesTracking;
if (tracker != null)
{
var calculatedProperty = tracker.CurrentTracker;
if (calculatedProperty != null)
{
CalculatedProperty sourceProperty = null;
_calculatedProperties.Value.TryGetValue(propertyName, out sourceProperty);
if (sourceProperty == null)
{
sourceProperty = new CalculatedProperty(propertyName);
_calculatedProperties.Value.Add(propertyName, sourceProperty);
}
sourceProperty.AddTarget(calculatedProperty);
}
}
}
///-------------------------------------------------------------------------------------------------
/// <summary>
/// Calculated property.
/// </summary>
/// <typeparam name="T">
/// Generic type parameter.
/// </typeparam>
/// <param name="calculation">
/// The calculation.
/// </param>
/// <param name="propertyName">
/// Name of the property.
/// </param>
/// <returns>
/// A T.
/// </returns>
///-------------------------------------------------------------------------------------------------
protected T CalculatedProperty <T>(Func <T> calculation, [System.Runtime.CompilerServices.CallerMemberName] string propertyName = null)
{
Contract.RequiresNotEmpty(propertyName, "propertyName");
Contract.Requires(calculation, "calculation");
if (!(this is INotifyPropertyChanged) || (_schema.Schema.Behavior & DomainBehavior.Observable) != DomainBehavior.Observable)
{
return(calculation());
}
SetCalculatedPropertySource(propertyName);
var session = EnsuresRunInSession(true);
try
{
var tracker = (session ?? Session.Current) as ISupportsCalculatedPropertiesTracking;
Debug.Assert(tracker != null);
CalculatedProperty calculatedProperty = null;
_calculatedProperties.Value.TryGetValue(propertyName, out calculatedProperty);
if (calculatedProperty == null)
{
calculatedProperty = new CalculatedProperty(propertyName);
_calculatedProperties.Value.Add(propertyName, calculatedProperty);
}
if (calculatedProperty.Handler == null)
{
calculatedProperty.Handler = () => ((IPropertyChangedNotifier)this).NotifyPropertyChanged(propertyName);
}
using (tracker.PushCalculatedPropertyTracker(calculatedProperty))
{
return(calculatedProperty.GetResult(calculation));
}
}
finally
{
if (session != null)
{
session.AcceptChanges();
session.Dispose();
}
}
}
IDisposable ISupportsCalculatedPropertiesTracking.PushCalculatedPropertyTracker(CalculatedProperty tracker)
{
var ctx = SessionDataContext;
if (ctx == null)
{
return(Disposables.Empty);
}
if (ctx.Trackers == null)
{
ctx.Trackers = new Stack <CalculatedProperty>();
}
ctx.Trackers.Push(tracker);
return(Disposables.ExecuteOnDispose(() => SessionDataContext.Trackers.Pop()));
}
internal void AddTarget(CalculatedProperty calculatedProperty)
{
_targets.Add(calculatedProperty);
}
