/// <summary>
/// Initializes a new instance of the <see cref="T:UsedProperty"/> class.
/// </summary>
internal UsedPropertyChain(INotifyPropertyChanged parent, string name, UsedSubproperty child,
TraversalOptions traversalOptions)
: base(name, child, traversalOptions)
{
if (parent == null)
{
throw new ArgumentNullException("target");
}
this.Parent = parent;
this.TopLevelParent = this;
}
/// <summary>
/// Initializes a new instance of the <see cref="T:UsePropertyBase"/> class.
/// </summary>
internal UsedPropertyBase(string name, UsedSubproperty child,
TraversalOptions traversalOptions)
{
if (name == null)
{
throw new ArgumentNullException("name");
}
this.Child = child;
this.Name = name;
this.tracedItems = new List <INotifyPropertyChanged>();
this.TraversalOptions = traversalOptions;
this.cyclicAccessGuard = new CyclicAccessGuard <AccessTrace>(1, cyclicAccessRecord);
}
private static UsedSubproperty GetContinuationChainLink(
MemberExpression memberExpression,
ChildInformation child,
TraversalOptions options)
{
Func <INotifyPropertyChanged> parentRetriever =
CompileObjectFactoryExpressionINPC(memberExpression.Expression);
if (parentRetriever == null)
{
//This happens when parentMember refers to a non-observable collection
return(null);
}
var usedSub = new UsedSubproperty(memberExpression.Member.Name, parentRetriever,
child.Property, options);
usedSub.TargetRetriever = CompileMemberExpression(memberExpression);
return(usedSub);
}
private static void GetUsedProperties(Set <UsedPropertyChain> container,
MemberExpression memberExpression,
ChildInformation child,
TraversalOptions options)
{
if (memberExpression == null)
{
return;
}
MemberTypes memberType = memberExpression.Member.MemberType;
if (memberType != MemberTypes.Property)
{
if (memberType == MemberTypes.Field)
{
if (options.TrackFields)
{
var constant = memberExpression.Expression as ConstantExpression;
if (constant != null)
{
HandleFieldConstant(container, memberExpression, child, options);
return;
}
if (IsFieldChain(memberExpression) && child.IsTrackable)
{
//Occurs with a.b.c.A kind of expression, where
//the field chain is the leading part of the
//expression and the constant can be extracted from
//it. The constant is taken from evaluation of a.b.c
HandleFieldConstant(container, memberExpression, child, options);
return;
}
else
{
//Dead end. It happens, when a field occurs
//after a non-constant element, e.g. after
//a property reference as in 'A.B.field.C'
//'A.B' is not ConstantExpression and therefore,
//even with TrackFields on, the field cannot be
//tracked any further. However, the preceding
//part of the expression can and should be
//tracked.
//Break the chain (without continuation)
GetUsedProperties(container, memberExpression.Expression, ChildInformation.FieldBreak, options);
return;
}
}
else
{
//Break the chain (without continuation)
GetUsedProperties(container, memberExpression.Expression, ChildInformation.FieldBreak, options);
return;
}
}
throw new InvalidOperationException("Unhandled case. Revise the code");
}
var parentMember = memberExpression.Expression as MemberExpression;
if (parentMember != null)
{
UsedSubproperty usedSubProperty = GetContinuationChainLink(memberExpression, child, options);
var usedChild = new ChildInformation(usedSubProperty);
//Continue the chain
GetUsedProperties(container, parentMember, usedChild, options);
}
else
{
if (memberExpression.Expression is ParameterExpression)
{
//Presumably, we are within a nested lambda parameter block.
//Skip, just for now. If there's a nested lambda like "c=>c.property" it
//is pretty complicated to know when to update.
//TODO:
return;
}
var constant = memberExpression.Expression as ConstantExpression;
if (constant != null)
{
var notifiable = constant.Value as INotifyPropertyChanged;
if (notifiable != null)
{
string propertyName = memberExpression.Member.Name;
var chain = new UsedPropertyChain(notifiable, propertyName, child.Property, options);
chain.TargetRetriever = CompileMemberExpression(memberExpression);
container.Add(chain);
}
else
{
//Even now add a chain to the container. Fields are not traced, but their
//properties can be. This applies only to cases where a the left-hand part
//of an expression is a field or a field/constant chain.
HandleFieldConstant(container, memberExpression, child, options);
}
return;
}
else
{
UsedSubproperty usedSubProperty = GetContinuationChainLink(memberExpression, child, options);
var usedChild = new ChildInformation(usedSubProperty);
//This should break the notification chain or continue, if it's marker method.
GetUsedProperties(container, memberExpression.Expression, usedChild, options);
}
}
}
/// <summary>
/// Initializes a new instance of the <see cref="T:UsedSubproperty"/> class.
/// </summary>
internal UsedSubproperty(string name, Func <INotifyPropertyChanged> parentRetriever, UsedSubproperty child,
TraversalOptions traversalOptions)
: base(name, child, traversalOptions)
{
if (parentRetriever == null)
{
throw new ArgumentNullException("parentRetriever");
}
this.parentRetriever = parentRetriever;
}
/// <summary>
/// Initializes a new instance of the <see cref="T:ChildInformation"/> class.
/// </summary>
public ChildInformation(MemberTypes childMemberType)
{
this.MemberType = childMemberType;
this.Property = null;
}
/// <summary>
/// Initializes a new instance of the <see cref="T:ChildInformation"/> class.
/// </summary>
public ChildInformation(UsedSubproperty subProperty)
{
this.Property = subProperty;
this.MemberType = subProperty == null ? MemberTypeUnknown : MemberTypes.Property;
}