public virtual void Creating(ShapeCreatingContext context)
{
}
public IShape Create(string shapeType, INamedEnumerable <object> parameters, Func <dynamic> createShape)
{
var defaultShapeTable = _shapeTableLocator.Value.Lookup(null);
ShapeDescriptor shapeDescriptor;
defaultShapeTable.Descriptors.TryGetValue(shapeType, out shapeDescriptor);
parameters = parameters ?? Arguments.Empty();
var creatingContext = new ShapeCreatingContext
{
New = this,
ShapeFactory = this,
ShapeType = shapeType,
OnCreated = new List <Action <ShapeCreatedContext> >()
};
IEnumerable <object> positional = parameters.Positional.ToList();
var baseType = positional.FirstOrDefault() as Type;
if (baseType == null)
{
// default to common base class
creatingContext.Create = createShape ?? (() => new Shape());
}
else
{
// consume the first argument
positional = positional.Skip(1);
creatingContext.Create = () => Activator.CreateInstance(baseType);
}
// "creating" events may add behaviors and alter base type)
foreach (var ev in _events)
{
ev.Value.Creating(creatingContext);
}
if (shapeDescriptor != null)
{
foreach (var ev in shapeDescriptor.Creating)
{
ev(creatingContext);
}
}
// create the new instance
var createdContext = new ShapeCreatedContext
{
New = creatingContext.New,
ShapeType = creatingContext.ShapeType,
Shape = creatingContext.Create()
};
if (!(createdContext.Shape is IShape))
{
throw new InvalidOperationException("Invalid base type for shape: " + createdContext.Shape.GetType().ToString());
}
ShapeMetadata shapeMetadata = createdContext.Shape.Metadata;
createdContext.Shape.Metadata.Type = shapeType;
if (shapeDescriptor != null)
{
shapeMetadata.Wrappers = shapeMetadata.Wrappers.Concat(shapeDescriptor.Wrappers).ToList();
}
// "created" events provides default values and new object initialization
foreach (var ev in _events)
{
ev.Value.Created(createdContext);
}
if (shapeDescriptor != null)
{
foreach (var ev in shapeDescriptor.Created)
{
ev(createdContext);
}
}
foreach (var ev in creatingContext.OnCreated)
{
ev(createdContext);
}
// other properties passed with call overlay any defaults, so are after the created events
// only one non-Type, non-named argument is allowed
var initializer = positional.SingleOrDefault();
if (initializer != null)
{
foreach (var prop in initializer.GetType().GetProperties())
{
createdContext.Shape[prop.Name] = prop.GetValue(initializer, null);
}
}
foreach (var kv in parameters.Named)
{
createdContext.Shape[kv.Key] = kv.Value;
}
return(createdContext.Shape);
}