/// <summary>
/// Applies the binding expression to a previously set source or target.
/// </summary>
void ApplyCore(object sourceObject, BindableObject target, BindableProperty property, bool fromTarget = false)
{
BindingMode mode = Binding.GetRealizedMode(_targetProperty);
if ((mode == BindingMode.OneWay || mode == BindingMode.OneTime) && fromTarget)
{
return;
}
bool needsGetter = (mode == BindingMode.TwoWay && !fromTarget) || mode == BindingMode.OneWay || mode == BindingMode.OneTime;
bool needsSetter = !needsGetter && ((mode == BindingMode.TwoWay && fromTarget) || mode == BindingMode.OneWayToSource);
object current = sourceObject;
BindingExpressionPart part = null;
for (var i = 0; i < _parts.Count; i++)
{
part = _parts[i];
if (!part.IsSelf && current != null)
{
// Allow the object instance itself to provide its own TypeInfo
TypeInfo currentType = current is IReflectableType reflectable?reflectable.GetTypeInfo() : current.GetType().GetTypeInfo();
if (part.LastGetter == null || !part.LastGetter.DeclaringType.GetTypeInfo().IsAssignableFrom(currentType))
{
SetupPart(currentType, part);
}
if (i < _parts.Count - 1)
{
part.TryGetValue(current, out current);
}
}
if (!part.IsSelf &&
current != null &&
((needsGetter && part.LastGetter == null) ||
(needsSetter && part.NextPart == null && part.LastSetter == null)))
{
Log.Warning("Binding", PropertyNotFoundErrorMessage, part.Content, current, target.GetType(), property.PropertyName);
break;
}
if (part.NextPart != null && (mode == BindingMode.OneWay || mode == BindingMode.TwoWay) &&
current is INotifyPropertyChanged inpc)
{
part.Subscribe(inpc);
}
}
Debug.Assert(part != null, "There should always be at least the self part in the expression.");
if (needsGetter)
{
if (part.TryGetValue(current, out object value) || part.IsSelf)
{
value = Binding.GetSourceValue(value, property.ReturnType);
}
else
{
value = Binding.FallbackValue ?? property.GetDefaultValue(target);
}
if (!TryConvert(ref value, property, property.ReturnType, true))
{
Log.Warning("Binding", "{0} can not be converted to type '{1}'", value, property.ReturnType);
return;
}
target.SetValueCore(property, value, SetValueFlags.ClearDynamicResource, BindableObject.SetValuePrivateFlags.Default | BindableObject.SetValuePrivateFlags.Converted);
}
else if (needsSetter && part.LastSetter != null && current != null)
{
object value = Binding.GetTargetValue(target.GetValue(property), part.SetterType);
if (!TryConvert(ref value, property, part.SetterType, false))
{
Log.Warning("Binding", "{0} can not be converted to type '{1}'", value, part.SetterType);
return;
}
object[] args;
if (part.IsIndexer)
{
args = new object[part.Arguments.Length + 1];
part.Arguments.CopyTo(args, 0);
args[args.Length - 1] = value;
}
else if (part.IsBindablePropertySetter)
{
args = new[] { part.BindablePropertyField, value };
}
else
{
args = new[] { value };
}
part.LastSetter.Invoke(current, args);
}
}
static void SetValueFromRenderer(BindableObject bindable, BindableProperty property, object value)
{
bindable.SetValueCore(property, value);
}