/// <summary>
/// Notifies that the visitor entered a node.
/// </summary>
/// <param name="type">The type of node the visitor entered.</param>
/// <returns>True if this call has pushed a value to <see cref="EnteredTypes"/>, False otherwise.</returns>
/// <remarks>The value returned by this method should be passed to the corresponding call to <see cref="LeaveNode"/>.</remarks>
public bool EnterNode(Type type)
{
// EnterNode should not be called from inside a part that should be serialized as a reference - this will also fail if calls to LeaveNode are missing.
if (SerializeAsReference)
{
throw new InvalidOperationException("EnterNode invoked inside a node that should be serialized as a reference.");
}
// Is this a referenceable type?
var typeAttribute = References.FirstOrDefault(x => x.ReferenceableType.IsAssignableFrom(type));
if (typeAttribute != null)
{
// What is the last referenceable type we entered? (serialized as-is instead of referenced)
var lastEntered = EnteredTypes.Count > 0 ? EnteredTypes.Peek() : null;
// It is a container for the type we're evaluating?
if (lastEntered != null && !lastEntered.ContainedTypes.Any(x => x.IsAssignableFrom(type)))
{
// Otherwise, serialize a reference to this object instead.
SerializeAsReference = true;
}
EnteredTypes.Push(typeAttribute);
return(true);
}
return(false);
}
/// <summary>
/// Notifies that the visitor left a node.
/// </summary>
/// <param name="type">The type of node the visitor left.</param>
/// <param name="removeLastEnteredType">If True, the last value on the <see cref="EnteredTypes"/> stack will be removed.</param>
/// <remarks>The value passed to <paramref name="removeLastEnteredType"/> should be the return value of <see cref="EnterNode"/>.</remarks>
public void LeaveNode(Type type, bool removeLastEnteredType)
{
// Reset this flag for sanity
SerializeAsReference = false;
// Did we enter a referenceable type and actually serialized it?
if (removeLastEnteredType)
{
EnteredTypes.Pop();
}
}