/// <summary>
/// Trys to create an OpenXmlElement from the specified namespace URI and local name.
/// </summary>
/// <param name="parent">The parent element.</param>
/// <param name="fileFormat">The specified file format version.</param>
/// <param name="namespaceUri">The namespace URI of the requested child element.</param>
/// <param name="localName">The local name of the requested child element.</param>
/// <returns>A new OpenXmlElement if the parent element can contains a child with the specified namespace and local name. Otherwise, returns null.</returns>
internal static OpenXmlElement?TryCreateValidChild(this OpenXmlElement parent, FileFormatVersions fileFormat, string namespaceUri, string localName)
{
Debug.Assert(parent is OpenXmlCompositeElement);
var newElement = parent.CreateElement(OpenXmlQualifiedName.Create(namespaceUri, string.Empty, localName));
if (newElement is OpenXmlUnknownElement || !newElement.IsInVersion(fileFormat))
{
return(null);
}
return(newElement);
}
/// <summary>
/// Populates the XML into a strong typed DOM tree.
/// </summary>
/// <param name="xmlReader">The XmlReader to read the XML content.</param>
/// <param name="loadMode">Specifies a load mode that is either lazy or full.</param>
private protected override void Populate(XmlReader xmlReader, OpenXmlLoadMode loadMode)
{
LoadAttributes(xmlReader);
if (!xmlReader.IsEmptyElement)
{
xmlReader.Read(); // read this element
while (!xmlReader.EOF)
{
// O15:#3024890, OpenXmlCompositeElement ignores the Whitespace NodeType.
if (xmlReader.NodeType == XmlNodeType.Whitespace)
{
xmlReader.Skip();
continue;
}
else if (xmlReader.NodeType == XmlNodeType.EndElement)
{
Debug.Assert(string.Equals(xmlReader.LocalName, LocalName, StringComparison.Ordinal));
xmlReader.Skip(); // move to next node
break;
}
OpenXmlElement element = ElementFactory(xmlReader);
// set parent before Load( ) call. AlternateContentChoice need parent info on loading.
element.Parent = this;
bool isACB = element is AlternateContent;
if (isACB && element.OpenXmlElementContext is not null)
{
element.OpenXmlElementContext.ACBlockLevel++;
}
bool mcContextPushed = false;
if (!(element is OpenXmlMiscNode))
{
// push MC context based on the context of the child element to be loaded
mcContextPushed = PushMcContext(xmlReader);
}
//Process the element according to the MC behavior
var action = ElementAction.Normal;
if (OpenXmlElementContext is not null && OpenXmlElementContext.MCSettings.ProcessMode != DocumentFormat.OpenXml.Packaging.MarkupCompatibilityProcessMode.NoProcess)
{
action = OpenXmlElementContext.MCContext.GetElementAction(element, OpenXmlElementContext.MCSettings.TargetFileFormatVersions);
}
element.Load(xmlReader, loadMode);
if (mcContextPushed)
{
PopMcContext();
}
if (isACB && element.OpenXmlElementContext is not null)
{
element.OpenXmlElementContext.ACBlockLevel--;
}
switch (action)
{
case ElementAction.Normal:
{
AddANode(element);
break;
}
case ElementAction.Ignore:
{
element.Parent = null;
continue;
}
case ElementAction.ProcessContent:
{
element.Parent = null;
while (element.ChildElements.Count > 0)
{
if (element.FirstChild is not OpenXmlElement node)
{
break;
}
node.Remove();
var newnode = default(OpenXmlElement);
// If node is an UnknowElement, we should try to see whether the parent element can load the node as strong typed element
if (node is OpenXmlUnknownElement)
{
newnode = CreateElement(OpenXmlQualifiedName.Create(node.NamespaceUri, node.Prefix, node.LocalName));
if (!(newnode is OpenXmlUnknownElement))
{
// The following method will load teh element in MCMode.Full
// since the node is already MC-processed when loading as unknown type, full loading the outerXml is fine
newnode.OuterXml = node.OuterXml;
// unnecessary xmlns attribute will be added, remove it.
RemoveUnnecessaryExtAttr(node, newnode);
}
else
{
newnode = null;
}
}
if (newnode is not null)
{
AddANode(newnode);
}
else
{
//append the original node
AddANode(node);
}
}
break;
}
case ElementAction.ACBlock:
{
if (element is not AlternateContent acb)
{
break;
}
var effectiveNode = OpenXmlElementContext?.MCContext.GetContentFromACBlock(acb, OpenXmlElementContext.MCSettings.TargetFileFormatVersions);
if (effectiveNode is null)
{
break;
}
element.Parent = null;
effectiveNode.Parent = null;
while (effectiveNode.FirstChild is not null)
{
var node = effectiveNode.FirstChild;
node.Remove();
AddANode(node);
node.CheckMustUnderstandAttr();
}
break;
}
}
}
}
else
{
xmlReader.Skip();
}
// Set raw outer xml to empty to indicate that it passed
RawOuterXml = string.Empty;
}