public ExpressionNode BuildExpression(bool enableValidation)
{
ExpressionNode pathRoot = null;
ExpressionNode path = null;
foreach (var element in _elements)
{
ExpressionNode node = null;
switch (element)
{
case NotExpressionPathElement _:
node = new LogicalNotNode();
break;
case PropertyElement prop:
node = new PropertyAccessorNode(prop.Property.Name, enableValidation, new PropertyInfoAccessorPlugin(prop.Property, prop.AccessorFactory));
break;
case ArrayElementPathElement arr:
node = new PropertyAccessorNode(CommonPropertyNames.IndexerName, enableValidation, new ArrayElementPlugin(arr.Indices, arr.ElementType));
break;
case VisualAncestorPathElement visualAncestor:
node = new FindVisualAncestorNode(visualAncestor.AncestorType, visualAncestor.Level);
break;
case AncestorPathElement ancestor:
node = new FindAncestorNode(ancestor.AncestorType, ancestor.Level);
break;
case SelfPathElement _:
node = new SelfNode();
break;
case ElementNameElement name:
node = new ElementNameNode(name.NameScope, name.Name);
break;
case IStronglyTypedStreamElement stream:
node = new StreamNode(stream.CreatePlugin());
break;
case ITypeCastElement typeCast:
node = new StrongTypeCastNode(typeCast.Type, typeCast.Cast);
break;
default:
throw new InvalidOperationException($"Unknown binding path element type {element.GetType().FullName}");
}
path = pathRoot is null ? (pathRoot = node) : path.Next = node;
}
return(pathRoot ?? new EmptyExpressionNode());
}
public void Should_Not_Throw_Exception_On_Duplicate_Properties()
{
// Repro of https://github.com/AvaloniaUI/Avalonia/issues/4733.
var source = new MyViewModel();
var target = new PropertyAccessorNode("Name", false);
target.Target = new WeakReference <object>(source);
var result = new List <object>();
target.Subscribe(x => result.Add(x));
}
public void Should_Not_Throw_Exception_On_Unsubscribe_When_Already_Unsubscribed()
{
var source = new Class1 {
Foo = "foo"
};
var target = new PropertyAccessorNode("Foo", false);
Assert.NotNull(target);
target.Target = new WeakReference <object>(source);
target.Subscribe(_ => { });
target.Unsubscribe();
target.Unsubscribe();
Assert.True(true);
}
public void Should_Not_Throw_Exception_When_Enabling_Data_Validation_On_Missing_Member()
{
var source = new Class1();
var target = new PropertyAccessorNode("NotFound", true);
target.Target = new WeakReference <object>(source);
var result = new List <object>();
target.Subscribe(x => result.Add(x));
Assert.Equal(
new object[]
{
new BindingNotification(
new MissingMemberException("Could not find a matching property accessor for 'NotFound' on 'Avalonia.Base.UnitTests.Data.Core.ExpressionObserverTests_Property+Class1'"),
BindingErrorType.Error),
},
result);
}
public (ExpressionNode?Node, SourceMode Mode) Parse(ref CharacterReader r)
{
ExpressionNode?rootNode = null;
ExpressionNode?node = null;
var(astNodes, mode) = BindingExpressionGrammar.Parse(ref r);
foreach (var astNode in astNodes)
{
ExpressionNode?nextNode = null;
switch (astNode)
{
case BindingExpressionGrammar.EmptyExpressionNode _:
nextNode = new EmptyExpressionNode();
break;
case BindingExpressionGrammar.NotNode _:
nextNode = new LogicalNotNode();
break;
case BindingExpressionGrammar.StreamNode _:
nextNode = new StreamNode();
break;
case BindingExpressionGrammar.PropertyNameNode propName:
nextNode = new PropertyAccessorNode(propName.PropertyName, _enableValidation);
break;
case BindingExpressionGrammar.IndexerNode indexer:
nextNode = new StringIndexerNode(indexer.Arguments);
break;
case BindingExpressionGrammar.AttachedPropertyNameNode attachedProp:
nextNode = ParseAttachedProperty(attachedProp);
break;
case BindingExpressionGrammar.SelfNode _:
nextNode = new SelfNode();
break;
case BindingExpressionGrammar.AncestorNode ancestor:
nextNode = ParseFindAncestor(ancestor);
break;
case BindingExpressionGrammar.NameNode elementName:
nextNode = new ElementNameNode(_nameScope ?? throw new NotSupportedException("Invalid element name binding with null name scope!"), elementName.Name);
break;
case BindingExpressionGrammar.TypeCastNode typeCast:
nextNode = ParseTypeCastNode(typeCast);
break;
}
if (node is null)
{
rootNode = node = nextNode;
}
else
{
node.Next = nextNode;
node = nextNode;
}
}
return(rootNode, mode);
}
