internal static XIdentifierBox Box <TType, TId>(XIdentifier <TType, TId> identifier)
where TType : class =>
new XIdentifierBox(identifier)
{
Type = typeof(TType),
IdType = typeof(TId),
getId = (obj) => identifier.GetId((TType)obj),
canId = (type) => identifier.CanId(type),
defaultValue = ReflectionTools.GetDefaultValue(typeof(TId)),
equals = (x, y) => identifier.Equals((TType)x, (TType)y),
hashCode = (obj) => identifier.GetHashCode((TType)obj),
keyEquals = (x, y) => identifier.KeyComparer.Equals((TId)x, (TId)y),
keyHash = (obj) => identifier.KeyComparer.GetHashCode((TId)obj)
};
protected override bool OnRead <T>(IXReadOperation reader, XType <T> xType, XElement element, Func <object, bool> assign,
XObjectArgs args)
{
Type type = typeof(T);
// A serialized reference has no attributes, no elements, some text, is of a type that can be ID'd,
// and not of a type that has a registered XTexter
string value = element.Value;
if (!element.HasAttributes &&
!element.HasElements &&
!string.IsNullOrEmpty(value) &&
xType.Component <XTexter <T> >() == null &&
Identifier.CanId(type, out Type idType))
{
bool idFound = false;
object id = null;
reader.Read(element, idType, x =>
{
idFound = true;
if (!Identifier.KeyComparer.Equals(x, ReflectionTools.GetDefaultValue(idType)))
{
id = x;
}
return(true);
},
XObjectArgs.DefaultIgnoreElementName);
// Schedule a task to assign the object if it shows up in the dictionary
reader.AddTask(this, () =>
{
if (!idFound)
{
return(false);
}
if (id == null)
{
return(true);
}
if (referenceObjects.TryGetValue(id, out object refObject))
{
if (refObject == null || type == refObject.GetType())
{
return(assign(refObject));
}
else
{
throw new InvalidOperationException(
$"Possible collision: the reference object with ID {id} was of expected type {type.Name}, " +
$"but that ID resolved to an object of type {refObject.GetType().Name}.");
}
}
return(false);
});
return(true);
}
return(false);
}