protected override void StartListeningCore(WeakReference <object> reference)
{
reference.TryGetTarget(out object target);
IPropertyAccessorPlugin plugin = null;
foreach (IPropertyAccessorPlugin x in ExpressionObserver.PropertyAccessors)
{
if (x.Match(target, PropertyName))
{
plugin = x;
break;
}
}
var accessor = plugin?.Start(reference, PropertyName);
// We need to handle accessor fallback before handling validation. Validators do not support null accessors.
if (accessor == null)
{
reference.TryGetTarget(out object instance);
var message = $"Could not find a matching property accessor for '{PropertyName}' on '{instance}'";
var exception = new MissingMemberException(message);
accessor = new PropertyError(new BindingNotification(exception, BindingErrorType.Error));
}
if (_enableValidation && Next == null)
{
foreach (var validator in ExpressionObserver.DataValidators)
{
if (validator.Match(reference, PropertyName))
{
accessor = validator.Start(reference, PropertyName, accessor);
}
}
}
if (accessor is null)
{
throw new AvaloniaInternalException("Data validators must return non-null accessor.");
}
_accessor = accessor;
accessor.Subscribe(ValueChanged);
}
protected override void StartListeningCore(WeakReference <object> reference)
{
reference.TryGetTarget(out object target);
IPropertyAccessorPlugin plugin = null;
foreach (IPropertyAccessorPlugin x in ExpressionObserver.PropertyAccessors)
{
if (x.Match(target, PropertyName))
{
plugin = x;
break;
}
}
var accessor = plugin?.Start(reference, PropertyName);
if (_enableValidation && Next == null)
{
foreach (var validator in ExpressionObserver.DataValidators)
{
if (validator.Match(reference, PropertyName))
{
accessor = validator.Start(reference, PropertyName, accessor);
}
}
}
if (accessor == null)
{
reference.TryGetTarget(out object instance);
var message = $"Could not find a matching property accessor for '{PropertyName}' on '{instance}'";
var exception = new MissingMemberException(message);
accessor = new PropertyError(new BindingNotification(exception, BindingErrorType.Error));
}
_accessor = accessor;
accessor.Subscribe(ValueChanged);
}
protected override void StartListeningCore(WeakReference <object> reference)
{
reference.TryGetTarget(out object target);
IPropertyAccessorPlugin plugin = null;
foreach (IPropertyAccessorPlugin x in ExpressionObserver.PropertyAccessors)
{
if (x.Match(target, PropertyName))
{
plugin = x;
break;
}
}
var accessor = plugin?.Start(reference, PropertyName);
if (_enableValidation && Next == null)
{
foreach (var validator in ExpressionObserver.DataValidators)
{
if (validator.Match(reference, PropertyName))
{
accessor = validator.Start(reference, PropertyName, accessor);
}
}
}
if (accessor == null)
{
throw new NotSupportedException(
$"Could not find a matching property accessor for {PropertyName}.");
}
_accessor = accessor;
accessor.Subscribe(ValueChanged);
}
public PropertyAccessorNode(string propertyName, bool enableValidation, IPropertyAccessorPlugin customPlugin)
{
PropertyName = propertyName;
_enableValidation = enableValidation;
_customPlugin = customPlugin;
}
