private Patch CreatePatch( XmlNode sourceNode, XmlElement diffgramElement )
{
Debug.Assert( sourceNode.NodeType == XmlNodeType.Document ||
sourceNode.NodeType == XmlNodeType.DocumentFragment );
Patch patch = new Patch( sourceNode );
_sourceRootNode = sourceNode;
// create patch for <xmldiff> node children
CreatePatchForChildren( sourceNode,
diffgramElement,
patch );
return patch;
}
private void Patch(ref XmlNode sourceNode, XmlDocument diffDoc)
{
XmlElement diffgramEl = diffDoc.DocumentElement;
if (diffgramEl.LocalName != "xmldiff" || diffgramEl.NamespaceURI != XmlDiff.NamespaceUri)
{
XmlPatchError.Error(XmlPatchError.ExpectingDiffgramElement);
}
XmlNamedNodeMap diffgramAttributes = diffgramEl.Attributes;
XmlAttribute srcDocAttr = (XmlAttribute)diffgramAttributes.GetNamedItem("srcDocHash");
if (srcDocAttr == null)
{
XmlPatchError.Error(XmlPatchError.MissingSrcDocAttribute);
}
ulong hashValue = 0;
try
{
hashValue = ulong.Parse(srcDocAttr.Value);
}
catch
{
XmlPatchError.Error(XmlPatchError.InvalidSrcDocAttribute);
}
XmlAttribute optionsAttr = (XmlAttribute)diffgramAttributes.GetNamedItem("options");
if (optionsAttr == null)
{
XmlPatchError.Error(XmlPatchError.MissingOptionsAttribute);
}
// parse options
XmlDiffOptions xmlDiffOptions = XmlDiffOptions.None;
try
{
xmlDiffOptions = XmlDiff.ParseOptions(optionsAttr.Value);
}
catch
{
XmlPatchError.Error(XmlPatchError.InvalidOptionsAttribute);
}
_ignoreChildOrder = ((int)xmlDiffOptions & (int)XmlDiffOptions.IgnoreChildOrder) != 0;
// Calculate the hash value of source document and check if it agrees with
// of srcDocHash attribute value.
if (!XmlDiff.VerifySource(sourceNode, hashValue, xmlDiffOptions))
{
XmlPatchError.Error(XmlPatchError.SrcDocMismatch);
}
// Translate diffgram & Apply patch
if (sourceNode.NodeType == XmlNodeType.Document)
{
Patch patch = CreatePatch(sourceNode, diffgramEl);
// create temporary root element and move all document children under it
XmlDocument sourceDoc = (XmlDocument)sourceNode;
XmlElement tempRoot = sourceDoc.CreateElement("tempRoot");
XmlNode child = sourceDoc.FirstChild;
while (child != null)
{
XmlNode tmpChild = child.NextSibling;
if (child.NodeType != XmlNodeType.XmlDeclaration &&
child.NodeType != XmlNodeType.DocumentType)
{
sourceDoc.RemoveChild(child);
tempRoot.AppendChild(child);
}
child = tmpChild;
}
sourceDoc.AppendChild(tempRoot);
// Apply patch
XmlNode temp = null;
patch.Apply(tempRoot, ref temp);
// remove the temporary root element
if (sourceNode.NodeType == XmlNodeType.Document)
{
sourceDoc.RemoveChild(tempRoot);
Debug.Assert(tempRoot.Attributes.Count == 0);
while ((child = tempRoot.FirstChild) != null)
{
tempRoot.RemoveChild(child);
sourceDoc.AppendChild(child);
}
}
}
else if (sourceNode.NodeType == XmlNodeType.DocumentFragment)
{
Patch patch = CreatePatch(sourceNode, diffgramEl);
XmlNode temp = null;
patch.Apply(sourceNode, ref temp);
}
else
{
// create fragment with sourceNode as its only child
XmlDocumentFragment fragment = sourceNode.OwnerDocument.CreateDocumentFragment();
XmlNode previousSourceParent = sourceNode.ParentNode;
XmlNode previousSourceSibbling = sourceNode.PreviousSibling;
if (previousSourceParent != null)
{
previousSourceParent.RemoveChild(sourceNode);
}
if (sourceNode.NodeType != XmlNodeType.XmlDeclaration)
{
fragment.AppendChild(sourceNode);
}
else
{
fragment.InnerXml = sourceNode.OuterXml;
}
Patch patch = CreatePatch(fragment, diffgramEl);
XmlNode temp = null;
patch.Apply(fragment, ref temp);
XmlNodeList childNodes = fragment.ChildNodes;
if (childNodes.Count != 1)
{
XmlPatchError.Error(XmlPatchError.InternalErrorMoreThanOneNodeLeft, childNodes.Count.ToString());
}
sourceNode = childNodes.Item(0);
fragment.RemoveAll();
if (previousSourceParent != null)
{
previousSourceParent.InsertAfter(sourceNode, previousSourceSibbling);
}
}
}
