private static PathItemBase <T> BuildPath(Expression <Func <T, object> > pathExpession, Action <T> calculateAndSet)
{
var convertExpression = pathExpession.Body as UnaryExpression;
if (convertExpression != null &&
(convertExpression.NodeType != ExpressionType.Convert || convertExpression.Type != typeof(object)))
{
throw new NotSupportedException(string.Format(
"Unary expression {0} is not supported. Only \"convert to object\" expression is allowed in the end of path.", convertExpression));
}
var currentExpression = convertExpression != null ? convertExpression.Operand : pathExpession.Body;
PathItemBase <T> rootPathItem = null;
while (!(currentExpression is ParameterExpression))
{
var methodCall = currentExpression as MethodCallExpression;
if (methodCall != null)
{
if (!methodCall.Method.IsGenericMethod || !methodCall.Method.GetGenericMethodDefinition().Equals(CollectionExtensions.EachElementMethodInfo))
{
throw new NotSupportedException(string.Format("Call of method {0} is not supported. Only {1} call is supported for collections in path",
methodCall.Method, CollectionExtensions.EachElementMethodInfo));
}
rootPathItem = new CollectionPathItem <T>(rootPathItem, rootPathItem == null ? calculateAndSet : null);
var methodCallArgument = methodCall.Arguments.Single();
currentExpression = methodCallArgument;
continue;
}
var memberExpression = currentExpression as MemberExpression;
if (memberExpression == null)
{
throw new NotSupportedException(string.Format("Expected expression is member expression. Expression {0} is not supported.", currentExpression));
}
var property = memberExpression.Member;
var compiledGetter = BuildGetter(memberExpression.Expression.Type, property.Name);
rootPathItem = new PropertyPathItem <T>(compiledGetter, property.Name, rootPathItem, rootPathItem == null ? calculateAndSet : null);
currentExpression = memberExpression.Expression;
}
//The chain doesn't contain any element (i.e. the expression contains only root object root => root)
if (rootPathItem == null)
{
throw new NotSupportedException(string.Format("The path {0} is too short. It contains a root object only.", pathExpession));
}
rootPathItem = new PropertyPathItem <T>(o => o, string.Empty, rootPathItem, null);
return(rootPathItem);
}
public CollectionChangeSubscriber(object effectiveObject, CollectionPathItem <T> pathItem, Action <PathItemBase <T> > onChanged)
: base(effectiveObject, pathItem, onChanged)
{
var notifyCollectionChange = effectiveObject as INotifyCollectionChanged;
if (notifyCollectionChange != null)
{
SubscribeToCollectionChange(notifyCollectionChange);
}
foreach (var ancestor in InitAncestors(EffectiveObject))
{
Ancestors.Add(ancestor);
}
}
