private void AnalyzeLink(LinkNode linkItem)
{
var v = new FindRequirementsVisitor(_strategy);
Expression @override;
if (linkItem.Instance is LambdaExpression)
{
@override = v.Visit((LambdaExpression) linkItem.Instance);
}
else if (linkItem.Instance is Binding)
{
@override = v.Visit(((Binding) linkItem.Instance).BindingLambda);
}
else
{
throw new Exception("bad");
}
if (v.Modified)
{
linkItem.Expression = (LambdaExpression)@override;
}
foreach (var x in v.MemberRequirements)
{
ApplyMemberRequirement(x);
}
foreach (var x in v.MetadataRequirements)
{
ApplyMetadataRequirement(x);
}
foreach (var x in v.Constants)
{
// add the constant as a dependent of this expression
RegisterItem(x, linkItem);
}
}
private RenderNode RegisterItem(object instance, RenderNode dependent)
{
if (instance == null)
return null;
RenderNode result;
if (!_items.TryGetValue(instance, out result))
{
IEnumerable<object> elements;
switch (_strategy.ClassifyInstance(instance, out elements))
{
case InstanceType.Object:
result = new ObjectOrValueNode(instance, _nextId++, false);
break;
case InstanceType.Value:
result = new ObjectOrValueNode(instance, _nextId++, true);
break;
case InstanceType.Link:
result = new LinkNode(instance, _nextId++);
break;
case InstanceType.Collection:
var collection = new CollectionNode(instance, _nextId++);
result = collection;
collection.Elements.AddRange(elements.Select(x => RegisterItem(x, result)));
break;
}
if (result != null)
{
_items[instance] = result;
_newItems.Enqueue(result);
}
}
if (result != null && dependent != null) // TODO: consider requiring non null
{
result.Dependents.Add(dependent);
dependent.Dependencies.Add(result);
}
return result;
}
protected string RenderValue(LinkNode node)
{
var status = _renderSchedule.GetStatus(node);
status.HasEmitted = true;
var expression = node.Expression;
return PortAsLambda(expression).PortedText;
}