public NodeElement(
ElementIdentifier identifier,
IEnumerable <Element> childs)
: base(identifier)
{
r_childs = new ElementHashList(childs);
}
public override Difference CompareTo(Element oldElement)
{
if (oldElement == null)
{
throw new ArgumentNullException("oldElement");
}
if (!oldElement.Identifier.Equals(this.Identifier))
{
throw new MergeException("Cannot compare elements that does not share the same identifier.");
}
OperationOnParent operationOnParent;
ElementHashList oldChilds;
if (oldElement is EmptyElement)
{
operationOnParent = OperationOnParent.Added;
oldChilds = new ElementHashList();
}
else if (oldElement is NodeElement)
{
operationOnParent = OperationOnParent.Modified;
oldChilds = ((NodeElement)oldElement).Childs;
}
else
{
throw new MergeException(string.Format("Cannot compare a {0} to a {1}.", oldElement.GetType().Name, this.GetType().Name));
}
var differences = new List <Difference>();
var newChilds = this.Childs;
foreach (var oldChild in oldChilds)
{
var newChild = newChilds.Contains(oldChild.Identifier)
? newChilds[oldChild.Identifier]
: oldChild.Identifier.CreateEmptyElement();
var difference = newChild.CompareTo(oldChild);
if (difference != null)
{
differences.Add(difference);
}
}
foreach (var newChild in newChilds)
{
if (!oldChilds.Contains(newChild.Identifier))
{
Element oldChild = newChild.Identifier.CreateEmptyElement();
differences.Add(newChild.CompareTo(oldChild));
}
}
return(differences.Count > 0
? new NodeDifference(this.Identifier, operationOnParent, differences)
: null);
}
public override Element Apply(Difference difference)
{
if (difference == null)
{
throw new ArgumentNullException("difference");
}
if (!difference.Identifier.Equals(this.Identifier))
{
throw new MergeException("Cannot apply a difference that does not share the same identifier with the element.");
}
if (difference is NodeDifference)
{
var mergedChilds = new ElementHashList(r_childs);
foreach (var subdifference in ((NodeDifference)difference).Subdifferences)
{
switch (subdifference.OperationOnParent)
{
case OperationOnParent.Added:
mergedChilds.Add(subdifference.Identifier.CreateEmptyElement().Apply(subdifference));
break;
case OperationOnParent.Modified:
mergedChilds.AddOrUpdate(mergedChilds[subdifference.Identifier].Apply(subdifference));
break;
case OperationOnParent.Removed:
mergedChilds.Remove(subdifference.Identifier);
break;
default:
throw new ArgumentOutOfRangeException("subdifference.OperationOnParent", subdifference.OperationOnParent, "Invalid value");
}
}
return(new NodeElement(this.Identifier, mergedChilds));
}
else
{
throw new MergeException(string.Format("Cannot apply a {0} on a {1}.", difference.GetType().Name, this.GetType().Name));
}
}
