public static bool CustomValueConverter(XamlIlAstTransformationContext context,
IXamlIlAstValueNode node, IXamlIlType type, out IXamlIlAstValueNode result)
{
if (type.FullName == "System.TimeSpan" &&
node is XamlIlAstTextNode tn &&
!tn.Text.Contains(":"))
{
var seconds = double.Parse(tn.Text, CultureInfo.InvariantCulture);
result = new XamlIlStaticOrTargetedReturnMethodCallNode(tn,
type.FindMethod("FromSeconds", type, false, context.Configuration.WellKnownTypes.Double),
new[]
{
new XamlIlConstantNode(tn, context.Configuration.WellKnownTypes.Double, seconds)
});
return(true);
}
if (type.FullName == "Avalonia.AvaloniaProperty")
{
var scope = context.ParentNodes().OfType <AvaloniaXamlIlTargetTypeMetadataNode>().FirstOrDefault();
if (scope == null)
{
throw new XamlIlLoadException("Unable to find the parent scope for AvaloniaProperty lookup", node);
}
if (!(node is XamlIlAstTextNode text))
{
throw new XamlIlLoadException("Property should be a text node", node);
}
result = XamlIlAvaloniaPropertyHelper.CreateNode(context, text.Text, scope.TargetType, text);
return(true);
}
result = null;
return(false);
}
public static bool TryConvertValue(XamlIlAstTransformationContext context,
IXamlIlAstValueNode node, IXamlIlType type, XamlIlAstClrProperty propertyContext,
out IXamlIlAstValueNode rv)
{
rv = null;
var cfg = context.Configuration;
// Since we are doing a conversion anyway, it makes sense to check for the underlying nullable type
if (type.GenericTypeDefinition?.Equals(cfg.WellKnownTypes.NullableT) == true)
{
type = type.GenericArguments[0];
}
if (cfg.CustomValueConverter?.Invoke(context, node, type, out rv) == true)
{
return(true);
}
var nodeType = node.Type.GetClrType();
// Implicit type converters
if (!nodeType.Equals(cfg.WellKnownTypes.String))
{
return(false);
}
if (node is XamlIlAstTextNode tn)
{
if (type.IsEnum)
{
if (TypeSystemHelpers.TryGetEnumValueNode(type, tn.Text, tn, out var enumConstantNode))
{
rv = enumConstantNode;
return(true);
}
}
// Well known types
if (TypeSystemHelpers.ParseConstantIfTypeAllows(tn.Text, type, tn, out var constantNode))
{
rv = constantNode;
return(true);
}
if (type.FullName == "System.Type")
{
var resolvedType = XamlIlTypeReferenceResolver.ResolveType(context, tn.Text, false, tn, true);
rv = new XamlIlTypeExtensionNode(tn, resolvedType, type);
return(true);
}
if (cfg.WellKnownTypes.Delegate.IsAssignableFrom(type))
{
var invoke = type.FindMethod(m => m.Name == "Invoke");
var rootType = context.RootObject.Type.GetClrType();
var handler =
rootType.FindMethod(tn.Text, invoke.ReturnType, false, invoke.Parameters.ToArray());
if (handler != null)
{
rv = new XamlIlLoadMethodDelegateNode(tn, context.RootObject, type, handler);
return(true);
}
}
}
IXamlIlAstValueNode CreateInvariantCulture() =>
new XamlIlStaticOrTargetedReturnMethodCallNode(node,
cfg.WellKnownTypes.CultureInfo.Methods.First(x =>
x.IsPublic && x.IsStatic && x.Name == "get_InvariantCulture"), null);
var candidates = type.Methods.Where(m => m.Name == "Parse" &&
m.ReturnType.Equals(type) &&
m.Parameters.Count > 0 &&
m.Parameters[0].Equals(cfg.WellKnownTypes.String)).ToList();
// Types with parse method
var parser = candidates.FirstOrDefault(m =>
m.Parameters.Count == 2 &&
(
m.Parameters[1].Equals(cfg.WellKnownTypes.CultureInfo) ||
m.Parameters[1].Equals(cfg.WellKnownTypes.IFormatProvider)
)
)
?? candidates.FirstOrDefault(m => m.Parameters.Count == 1);
if (parser != null)
{
var args = new List <IXamlIlAstValueNode> {
node
};
if (parser.Parameters.Count == 2)
{
args.Add(CreateInvariantCulture());
}
rv = new XamlIlStaticOrTargetedReturnMethodCallNode(node, parser, args);
return(true);
}
if (cfg.TypeMappings.TypeDescriptorContext != null)
{
IXamlIlType converterType = null;
if (propertyContext?.TypeConverters.TryGetValue(type, out converterType) != true)
{
var typeConverterAttribute =
cfg.GetCustomAttribute(type, cfg.TypeMappings.TypeConverterAttributes).FirstOrDefault();
if (typeConverterAttribute != null)
{
converterType = TryGetTypeConverterFromCustomAttribute(cfg, typeConverterAttribute);
}
}
if (converterType != null)
{
var converterMethod = converterType.FindMethod("ConvertFrom", cfg.WellKnownTypes.Object, false,
cfg.TypeMappings.TypeDescriptorContext, cfg.WellKnownTypes.CultureInfo,
cfg.WellKnownTypes.Object);
rv = new XamlIlAstNeedsParentStackValueNode(node,
new XamlIlAstRuntimeCastNode(node,
new XamlIlStaticOrTargetedReturnMethodCallNode(node, converterMethod,
new[]
{
new XamlIlAstNewClrObjectNode(node,
new XamlIlAstClrTypeReference(node, converterType, false), null,
new List <IXamlIlAstValueNode>()),
new XamlIlAstContextLocalNode(node, cfg.TypeMappings.TypeDescriptorContext),
CreateInvariantCulture(), node
}), new XamlIlAstClrTypeReference(node, type, false)));
return(true);
}
}
return(false);
}
