private static bool IsDescendentOrSelf(SimpleXmlChange existingChange, SimpleXmlChange newChange)
{
var child = existingChange.Node;
var parent = newChange.Node;
if (child == parent)
{
if (child.Parent == null)
{
//either two deletes
//or a node N was added and then deleted
if (existingChange.Parent == newChange.Parent)
{
return true;
}
}
else if (newChange.Parent == existingChange.Parent)
{
//do not return true in case of move
return true;
}
}
var pe = parent as XElement;
if (pe != null)
{
for (var e = existingChange.Parent as XElement; e != null; e = e.Parent)
{
if (e == pe)
{
return true;
}
}
}
return false;
}
private void OnBeforeChange(object sender, XObjectChangeEventArgs e)
{
var node = sender as XObject;
// We do not allow editing DTDs through XmlModel
if (node is XDocumentType)
{
var msg = String.Format(CultureInfo.CurrentCulture, Resources.VanillaProvider_DtdNodesReadOnly);
throw new NotSupportedException(msg);
}
var action = e.ObjectChange;
currentChange = null;
XElement element = null;
XAttribute attribute = null;
XText text = null;
XProcessingInstruction pi = null;
XComment comment = null;
switch (action)
{
case XObjectChange.Add:
var addChange = new AddNodeChangeInternal(node, action);
currentChange = addChange;
break;
case XObjectChange.Remove:
var removeChange = new RemoveNodeChange(node, action);
removeChange.Parent = node.Parent;
if (removeChange.Parent == null)
{
removeChange.Parent = node.Document;
}
var attrib = (node as XAttribute);
if (attrib != null)
{
removeChange.NextNode = attrib.NextAttribute;
}
else
{
removeChange.NextNode = (node as XNode).NextNode;
}
currentChange = removeChange;
break;
case XObjectChange.Name:
var nameChange = new NodeNameChange(node, action);
if ((element = node as XElement) != null)
{
nameChange.OldName = element.Name;
}
else if ((pi = node as XProcessingInstruction) != null)
{
nameChange.OldName = XName.Get(pi.Target);
}
else
{
Debug.Assert(false, "The name of something changed that we're not handling here!");
throw new NotSupportedException();
}
currentChange = nameChange;
break;
case XObjectChange.Value:
var valueChange = new NodeValueChange(node, action);
if ((element = node as XElement) != null)
{
valueChange.OldValue = element.Value;
}
else if ((attribute = node as XAttribute) != null)
{
valueChange.OldValue = attribute.Value;
}
else if ((text = node as XText) != null)
{
valueChange.OldValue = text.Value;
if (text.Parent != null)
{
valueChange.Parent = text.Parent;
}
else
{
valueChange.Parent = text.Document;
}
}
else if ((comment = node as XComment) != null)
{
valueChange.OldValue = comment.Value;
}
else if ((pi = node as XProcessingInstruction) != null)
{
valueChange.OldValue = pi.Data;
}
else
{
Debug.Assert(false, "The value of something changed that we're not handling here!");
throw new NotSupportedException();
}
currentChange = valueChange;
break;
}
}
private RemoveStatus RemoveAllDescendentChanges(SimpleXmlChange newChange)
{
// This node is being removed, therefore any change to any child of this
// node is now unnecessary, so we can filter them out.
var rc = RemoveStatus.None;
List<XmlModelCommand> toRemove = null;
for (int i = committedPosition, n = txCommands.Count; i < n; i++)
{
var cmd = txCommands[i];
var change = cmd.Change;
if (IsDescendentOrSelf(change, newChange))
{
if (change.Node == newChange.Node
&& change.Action == XObjectChange.Add)
{
rc = RemoveStatus.FoundSelfAdd; // we are removing an add of the same node!
}
if (toRemove == null)
{
toRemove = new List<XmlModelCommand>();
}
toRemove.Add(cmd);
}
}
RemoveRange(txCommands, toRemove);
return rc;
}
public XmlModelCommand(SimpleXmlChange change)
: base()
{
this._change = change;
}