private static IEnumerable <OpenXmlElement> ValidatingTraverse(OpenXmlElement inElement, MCContext mcContext, FileFormatVersions version)
{
var stack = new Stack <OpenXmlElement>();
stack.Push(inElement);
while (stack.Count > 0)
{
var element = stack.Pop();
if (element is null)
{
mcContext.PopMCAttributes2();
continue;
}
// 1. Skip elements in ProcessContent.
// 2. Select correct Choice / Fallback
// Need bookkeep MC context
// Need to collect MC context from ancestor
// bookkeep MC context,
// MC Spec: Compatibility-rule attributes shall affect the element to which they 1 are attached, including the element’s other attributes and contents.
mcContext.PushMCAttributes2(element.MCAttributes, element.LookupNamespace);
stack.Push(null);
if (element.IsStrongTypedElement())
{
// only call validate on elements that defined in the format.
if (version.AtLeast(element.InitialVersion))
{
yield return(element);
}
else if (mcContext.IsProcessContent(element))
{
// do not validate this element.
}
foreach (var child in element.ChildElements)
{
stack.Push(child);
}
}
else if (element.IsUnknown())
{
// TODO: Issue: all types are weak types now, need to change the Framework to load strong typed elements!!!
if (mcContext.IsProcessContent(element))
{
// do validating on children elements.
foreach (var child in element.ChildElements)
{
stack.Push(child);
}
}
}
else if (element.IsAlternateContent())
{
yield return(element);
var selectedContent = mcContext.GetContentFromACBlock((AlternateContent)element, version);
if (selectedContent is not null)
{
foreach (var child in selectedContent.ChildElements)
{
stack.Push(child);
}
}
}
else if (element.IsMiscNode())
{
// non-element node
// just skip
}
else
{
Debug.Assert(element is AlternateContentChoice || element is AlternateContentFallback);
Debug.Assert(element.Parent is not null && element.Parent is AlternateContent);
// should not be here, otherwise, wrong case ( the parent is not AlternateContent).
}
}
}
private static OpenXmlElement GetChildMc(this OpenXmlElement parent, OpenXmlElement child, MCContext mcContext, FileFormatVersions format)
{
// Use stack to cache the next siblings in different levels.
Stack <OpenXmlElement> nextSiblings = new Stack <OpenXmlElement>();
while (child != null)
{
var acb = child as AlternateContent;
if (acb == null && child.IsInVersion(format))
{
return(child);
}
else
{
mcContext.PushMCAttributes2(child.MCAttributes, child.LookupNamespace);
if (acb != null)
{
nextSiblings.Push(child.GetNextNonMiscElementSibling());
var select = mcContext.GetContentFromACBlock(acb, format);
if (select != null)
{
child = select.GetFirstNonMiscElementChild();
}
else
{
// The ACB has no children elements.
// case like: <acb/> <acb><choice/><fallback/></acb>
child = null;
}
}
else
{
// Ignorable element, skip it
if (mcContext.IsIgnorableNs(child.NamespaceUri))
{
// Any element marked with ProcessContent should be an Ignorable Element
if (mcContext.IsProcessContent(child))
{
nextSiblings.Push(child.GetNextNonMiscElementSibling());
//
child = child.GetFirstNonMiscElementChild();
}
else
{
child = child.GetNextNonMiscElementSibling();
}
}
else
{
mcContext.PopMCAttributes2();
return(child);
}
}
mcContext.PopMCAttributes2();
}
while (child == null && nextSiblings.Count > 0)
{
child = nextSiblings.Pop();
}
}
// child is null.
return(child);
}