Add types to the CXFA_Node::Get*{Child|Sibling}* methods

This CL templates the various Get methods in CXFA_Node in order to
return the correct node type.

Change-Id: I4f50df6dd9213873deb8f8f262eaf579c6c4ca7d
Reviewed-on: https://pdfium-review.googlesource.com/21230
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>
Commit-Queue: dsinclair <dsinclair@chromium.org>

19 files changed, 241 insertions, 138 deletions

diff --git a/fxjs/xfa/cjx_layoutpseudomodel.cpp b/fxjs/xfa/cjx_layoutpseudomodel.cpp
index 638da41eea..c275970744 100644
--- a/fxjs/xfa/cjx_layoutpseudomodel.cpp
+++ b/fxjs/xfa/cjx_layoutpseudomodel.cpp
@@ -17,6 +17,7 @@
 #include "xfa/fxfa/parser/cxfa_arraynodelist.h"
 #include "xfa/fxfa/parser/cxfa_containerlayoutitem.h"
 #include "xfa/fxfa/parser/cxfa_document.h"
+#include "xfa/fxfa/parser/cxfa_form.h"
 #include "xfa/fxfa/parser/cxfa_layoutitem.h"
 #include "xfa/fxfa/parser/cxfa_layoutprocessor.h"
 #include "xfa/fxfa/parser/cxfa_measurement.h"
@@ -400,7 +401,8 @@ CJS_Return CJX_LayoutPseudoModel::relayout(
     CJS_V8* runtime,
     const std::vector<v8::Local<v8::Value>>& params) {
   CXFA_Node* pRootNode = GetDocument()->GetRoot();
-  CXFA_Node* pFormRoot = pRootNode->GetFirstChildByClass(XFA_Element::Form);
+  CXFA_Form* pFormRoot =
+      pRootNode->GetFirstChildByClass<CXFA_Form>(XFA_Element::Form);
   CXFA_Node* pContentRootNode = pFormRoot->GetNodeItem(XFA_NODEITEM_FirstChild);
   CXFA_LayoutProcessor* pLayoutProcessor = GetDocument()->GetLayoutProcessor();
   if (pContentRootNode)
diff --git a/fxjs/xfa/cjx_object.cpp b/fxjs/xfa/cjx_object.cpp
index c49cc5bbce..fcf77d434d 100644
--- a/fxjs/xfa/cjx_object.cpp
+++ b/fxjs/xfa/cjx_object.cpp
@@ -26,7 +26,10 @@
 #include "xfa/fxfa/parser/cxfa_measurement.h"
 #include "xfa/fxfa/parser/cxfa_node.h"
 #include "xfa/fxfa/parser/cxfa_object.h"
+#include "xfa/fxfa/parser/cxfa_occur.h"
 #include "xfa/fxfa/parser/cxfa_occurdata.h"
+#include "xfa/fxfa/parser/cxfa_proto.h"
+#include "xfa/fxfa/parser/cxfa_subform.h"
 #include "xfa/fxfa/parser/cxfa_validate.h"
 #include "xfa/fxfa/parser/cxfa_value.h"
 #include "xfa/fxfa/parser/xfa_utils.h"
@@ -1217,9 +1220,9 @@ void CJX_Object::Script_Attribute_String(CFXJSE_Value* pValue,
 
   CXFA_Node* pTemplateNode =
       ToNode(GetDocument()->GetXFAObject(XFA_HASHCODE_Template));
-  CXFA_Node* pProtoRoot =
-      pTemplateNode->GetFirstChildByClass(XFA_Element::Subform)
-          ->GetFirstChildByClass(XFA_Element::Proto);
+  CXFA_Proto* pProtoRoot =
+      pTemplateNode->GetFirstChildByClass<CXFA_Subform>(XFA_Element::Subform)
+          ->GetFirstChildByClass<CXFA_Proto>(XFA_Element::Proto);
 
   WideString wsID;
   WideString wsSOM;
diff --git a/xfa/fxfa/cxfa_ffdoc.cpp b/xfa/fxfa/cxfa_ffdoc.cpp
index 2d22fb8c68..bb05d66968 100644
--- a/xfa/fxfa/cxfa_ffdoc.cpp
+++ b/xfa/fxfa/cxfa_ffdoc.cpp
@@ -28,9 +28,12 @@
 #include "xfa/fxfa/cxfa_ffnotify.h"
 #include "xfa/fxfa/cxfa_ffwidget.h"
 #include "xfa/fxfa/cxfa_fontmgr.h"
+#include "xfa/fxfa/parser/cxfa_acrobat.h"
+#include "xfa/fxfa/parser/cxfa_acrobat7.h"
 #include "xfa/fxfa/parser/cxfa_dataexporter.h"
 #include "xfa/fxfa/parser/cxfa_dataimporter.h"
 #include "xfa/fxfa/parser/cxfa_document.h"
+#include "xfa/fxfa/parser/cxfa_dynamicrender.h"
 #include "xfa/fxfa/parser/cxfa_node.h"
 
 namespace {
@@ -245,16 +248,19 @@ void CXFA_FFDoc::StopLoad() {
   if (!pConfig)
     return;
 
-  CXFA_Node* pAcrobat = pConfig->GetFirstChildByClass(XFA_Element::Acrobat);
+  CXFA_Acrobat* pAcrobat =
+      pConfig->GetFirstChildByClass<CXFA_Acrobat>(XFA_Element::Acrobat);
   if (!pAcrobat)
     return;
 
-  CXFA_Node* pAcrobat7 = pAcrobat->GetFirstChildByClass(XFA_Element::Acrobat7);
+  CXFA_Acrobat7* pAcrobat7 =
+      pAcrobat->GetFirstChildByClass<CXFA_Acrobat7>(XFA_Element::Acrobat7);
   if (!pAcrobat7)
     return;
 
-  CXFA_Node* pDynamicRender =
-      pAcrobat7->GetFirstChildByClass(XFA_Element::DynamicRender);
+  CXFA_DynamicRender* pDynamicRender =
+      pAcrobat7->GetFirstChildByClass<CXFA_DynamicRender>(
+          XFA_Element::DynamicRender);
   if (!pDynamicRender)
     return;
 
diff --git a/xfa/fxfa/cxfa_ffdocview.cpp b/xfa/fxfa/cxfa_ffdocview.cpp
index ed91020dff..3fea83c0e7 100644
--- a/xfa/fxfa/cxfa_ffdocview.cpp
+++ b/xfa/fxfa/cxfa_ffdocview.cpp
@@ -32,6 +32,7 @@
 #include "xfa/fxfa/parser/cxfa_acrobat.h"
 #include "xfa/fxfa/parser/cxfa_binditemsdata.h"
 #include "xfa/fxfa/parser/cxfa_layoutprocessor.h"
+#include "xfa/fxfa/parser/cxfa_pageset.h"
 #include "xfa/fxfa/parser/cxfa_present.h"
 #include "xfa/fxfa/parser/cxfa_subform.h"
 #include "xfa/fxfa/parser/cxfa_validate.h"
@@ -120,8 +121,8 @@ void CXFA_FFDocView::StopLayout() {
   if (!pSubformNode)
     return;
 
-  CXFA_Node* pPageSetNode =
-      pSubformNode->GetFirstChildByClass(XFA_Element::PageSet);
+  CXFA_PageSet* pPageSetNode =
+      pSubformNode->GetFirstChildByClass<CXFA_PageSet>(XFA_Element::PageSet);
   if (!pPageSetNode)
     return;
 
@@ -315,7 +316,7 @@ CXFA_FFWidgetHandler* CXFA_FFDocView::GetWidgetHandler() {
 
 std::unique_ptr<CXFA_WidgetAccIterator>
 CXFA_FFDocView::CreateWidgetAccIterator() {
-  CXFA_Node* pFormRoot = GetRootSubform();
+  CXFA_Subform* pFormRoot = GetRootSubform();
   return pFormRoot ? pdfium::MakeUnique<CXFA_WidgetAccIterator>(pFormRoot)
                    : nullptr;
 }
@@ -775,11 +776,12 @@ void CXFA_FFDocView::SetChangeMark() {
   m_pDoc->GetDocEnvironment()->SetChangeMark(m_pDoc.Get());
 }
 
-CXFA_Node* CXFA_FFDocView::GetRootSubform() {
+CXFA_Subform* CXFA_FFDocView::GetRootSubform() {
   CXFA_Node* pFormPacketNode =
       ToNode(m_pDoc->GetXFADoc()->GetXFAObject(XFA_HASHCODE_Form));
   if (!pFormPacketNode)
     return nullptr;
 
-  return pFormPacketNode->GetFirstChildByClass(XFA_Element::Subform);
+  return pFormPacketNode->GetFirstChildByClass<CXFA_Subform>(
+      XFA_Element::Subform);
 }
diff --git a/xfa/fxfa/cxfa_ffdocview.h b/xfa/fxfa/cxfa_ffdocview.h
index 8be5cf16b8..e5b27b58ea 100644
--- a/xfa/fxfa/cxfa_ffdocview.h
+++ b/xfa/fxfa/cxfa_ffdocview.h
@@ -18,6 +18,7 @@
 class CXFA_FFWidgetHandler;
 class CXFA_FFDoc;
 class CXFA_FFWidget;
+class CXFA_Subform;
 class CXFA_WidgetAccIterator;
 
 extern const XFA_AttributeEnum gs_EventActivity[];
@@ -116,7 +117,7 @@ class CXFA_FFDocView {
   size_t RunCalculateRecursive(size_t index);
   void ShowNullTestMsg();
   bool ResetSingleWidgetAccData(CXFA_WidgetAcc* pWidgetAcc);
-  CXFA_Node* GetRootSubform();
+  CXFA_Subform* GetRootSubform();
 
   UnownedPtr<CXFA_FFDoc> const m_pDoc;
   std::unique_ptr<CXFA_FFWidgetHandler> m_pWidgetHandler;
diff --git a/xfa/fxfa/cxfa_ffwidgethandler.cpp b/xfa/fxfa/cxfa_ffwidgethandler.cpp
index 685e92d61a..7fe3c17ff5 100644
--- a/xfa/fxfa/cxfa_ffwidgethandler.cpp
+++ b/xfa/fxfa/cxfa_ffwidgethandler.cpp
@@ -13,9 +13,11 @@
 #include "xfa/fxfa/cxfa_fffield.h"
 #include "xfa/fxfa/cxfa_ffwidget.h"
 #include "xfa/fxfa/cxfa_fwladapterwidgetmgr.h"
+#include "xfa/fxfa/parser/cxfa_checkbutton.h"
 #include "xfa/fxfa/parser/cxfa_layoutprocessor.h"
 #include "xfa/fxfa/parser/cxfa_measurement.h"
 #include "xfa/fxfa/parser/cxfa_node.h"
+#include "xfa/fxfa/parser/cxfa_ui.h"
 #include "xfa/fxfa/parser/cxfa_validate.h"
 
 CXFA_FFWidgetHandler::CXFA_FFWidgetHandler(CXFA_FFDocView* pDocView)
@@ -354,8 +356,9 @@ CXFA_Node* CXFA_FFWidgetHandler::CreateExclGroup(CXFA_Node* pParent,
 CXFA_Node* CXFA_FFWidgetHandler::CreateRadioButton(CXFA_Node* pParent,
                                                    CXFA_Node* pBefore) const {
   CXFA_Node* pField = CreateField(XFA_Element::CheckButton, pParent, pBefore);
-  CXFA_Node* pUi = pField->GetFirstChildByClass(XFA_Element::Ui);
-  CXFA_Node* pWidget = pUi->GetFirstChildByClass(XFA_Element::CheckButton);
+  CXFA_Ui* pUi = pField->GetFirstChildByClass<CXFA_Ui>(XFA_Element::Ui);
+  CXFA_CheckButton* pWidget =
+      pUi->GetFirstChildByClass<CXFA_CheckButton>(XFA_Element::CheckButton);
   pWidget->JSObject()->SetEnum(XFA_Attribute::Shape, XFA_AttributeEnum::Round,
                                false);
   return pField;
diff --git a/xfa/fxfa/parser/cxfa_containerlayoutitem.cpp b/xfa/fxfa/parser/cxfa_containerlayoutitem.cpp
index 28c0c2eedd..e47a9931a3 100644
--- a/xfa/fxfa/parser/cxfa_containerlayoutitem.cpp
+++ b/xfa/fxfa/parser/cxfa_containerlayoutitem.cpp
@@ -9,6 +9,7 @@
 #include "xfa/fxfa/parser/cxfa_layoutpagemgr.h"
 #include "xfa/fxfa/parser/cxfa_layoutprocessor.h"
 #include "xfa/fxfa/parser/cxfa_measurement.h"
+#include "xfa/fxfa/parser/cxfa_medium.h"
 #include "xfa/fxfa/parser/cxfa_node.h"
 
 CXFA_ContainerLayoutItem::CXFA_ContainerLayoutItem(CXFA_Node* pNode)
@@ -27,7 +28,8 @@ int32_t CXFA_ContainerLayoutItem::GetPageIndex() const {
 
 CFX_SizeF CXFA_ContainerLayoutItem::GetPageSize() const {
   CFX_SizeF size;
-  CXFA_Node* pMedium = m_pFormNode->GetFirstChildByClass(XFA_Element::Medium);
+  CXFA_Medium* pMedium =
+      m_pFormNode->GetFirstChildByClass<CXFA_Medium>(XFA_Element::Medium);
   if (!pMedium)
     return size;
 
diff --git a/xfa/fxfa/parser/cxfa_document.cpp b/xfa/fxfa/parser/cxfa_document.cpp
index 3ba5a44cf9..de057aa933 100644
--- a/xfa/fxfa/parser/cxfa_document.cpp
+++ b/xfa/fxfa/parser/cxfa_document.cpp
@@ -15,11 +15,14 @@
 #include "xfa/fxfa/parser/cscript_layoutpseudomodel.h"
 #include "xfa/fxfa/parser/cscript_logpseudomodel.h"
 #include "xfa/fxfa/parser/cscript_signaturepseudomodel.h"
+#include "xfa/fxfa/parser/cxfa_datagroup.h"
 #include "xfa/fxfa/parser/cxfa_document_parser.h"
 #include "xfa/fxfa/parser/cxfa_interactive.h"
 #include "xfa/fxfa/parser/cxfa_layoutprocessor.h"
 #include "xfa/fxfa/parser/cxfa_localemgr.h"
 #include "xfa/fxfa/parser/cxfa_node.h"
+#include "xfa/fxfa/parser/cxfa_pdf.h"
+#include "xfa/fxfa/parser/cxfa_present.h"
 #include "xfa/fxfa/parser/cxfa_traversestrategy_xfanode.h"
 #include "xfa/fxfa/parser/xfa_resolvenode_rs.h"
 #include "xfa/fxfa/parser/xfa_utils.h"
@@ -154,11 +157,13 @@ CXFA_Object* CXFA_Document::GetXFAObject(XFA_HashCode dwNodeNameHash) {
       if (!pDatasetsNode)
         return nullptr;
 
-      for (CXFA_Node* pDatasetsChild =
-               pDatasetsNode->GetFirstChildByClass(XFA_Element::DataGroup);
+      for (CXFA_DataGroup* pDatasetsChild =
+               pDatasetsNode->GetFirstChildByClass<CXFA_DataGroup>(
+                   XFA_Element::DataGroup);
            pDatasetsChild;
-           pDatasetsChild = pDatasetsChild->GetNextSameClassSibling(
-               XFA_Element::DataGroup)) {
+           pDatasetsChild =
+               pDatasetsChild->GetNextSameClassSibling<CXFA_DataGroup>(
+                   XFA_Element::DataGroup)) {
         if (pDatasetsChild->GetNameHash() != XFA_HASHCODE_Data)
           continue;
 
@@ -178,7 +183,8 @@ CXFA_Object* CXFA_Document::GetXFAObject(XFA_HashCode dwNodeNameHash) {
     }
     case XFA_HASHCODE_Record: {
       CXFA_Node* pData = ToNode(GetXFAObject(XFA_HASHCODE_Data));
-      return pData ? pData->GetFirstChildByClass(XFA_Element::DataGroup)
+      return pData ? pData->GetFirstChildByClass<CXFA_DataGroup>(
+                         XFA_Element::DataGroup)
                    : nullptr;
     }
     case XFA_HASHCODE_DataWindow: {
@@ -254,11 +260,12 @@ bool CXFA_Document::IsInteractive() {
   if (!pConfig)
     return false;
 
-  CXFA_Node* pPresent = pConfig->GetFirstChildByClass(XFA_Element::Present);
+  CXFA_Present* pPresent =
+      pConfig->GetFirstChildByClass<CXFA_Present>(XFA_Element::Present);
   if (!pPresent)
     return false;
 
-  CXFA_Node* pPDF = pPresent->GetFirstChildByClass(XFA_Element::Pdf);
+  CXFA_Pdf* pPDF = pPresent->GetFirstChildByClass<CXFA_Pdf>(XFA_Element::Pdf);
   if (!pPDF)
     return false;
 
diff --git a/xfa/fxfa/parser/cxfa_itemlayoutprocessor.cpp b/xfa/fxfa/parser/cxfa_itemlayoutprocessor.cpp
index a52821b218..0bf547a000 100644
--- a/xfa/fxfa/parser/cxfa_itemlayoutprocessor.cpp
+++ b/xfa/fxfa/parser/cxfa_itemlayoutprocessor.cpp
@@ -18,13 +18,17 @@
 #include "xfa/fxfa/parser/cxfa_containerlayoutitem.h"
 #include "xfa/fxfa/parser/cxfa_contentlayoutitem.h"
 #include "xfa/fxfa/parser/cxfa_document.h"
+#include "xfa/fxfa/parser/cxfa_keep.h"
 #include "xfa/fxfa/parser/cxfa_layoutcontext.h"
 #include "xfa/fxfa/parser/cxfa_layoutpagemgr.h"
 #include "xfa/fxfa/parser/cxfa_localemgr.h"
+#include "xfa/fxfa/parser/cxfa_margin.h"
 #include "xfa/fxfa/parser/cxfa_measurement.h"
 #include "xfa/fxfa/parser/cxfa_node.h"
 #include "xfa/fxfa/parser/cxfa_nodeiteratortemplate.h"
+#include "xfa/fxfa/parser/cxfa_occur.h"
 #include "xfa/fxfa/parser/cxfa_occurdata.h"
+#include "xfa/fxfa/parser/cxfa_para.h"
 #include "xfa/fxfa/parser/cxfa_traversestrategy_xfanode.h"
 #include "xfa/fxfa/parser/xfa_utils.h"
 
@@ -130,7 +134,8 @@ CFX_SizeF CalculateContainerComponentSizeFromContentSize(
     float fContentCalculatedHeight,
     const CFX_SizeF& currentContainerSize) {
   CFX_SizeF componentSize = currentContainerSize;
-  CXFA_Node* pMarginNode = pFormNode->GetFirstChildByClass(XFA_Element::Margin);
+  CXFA_Margin* pMarginNode =
+      pFormNode->GetFirstChildByClass<CXFA_Margin>(XFA_Element::Margin);
   if (bContainerWidthAutoSize) {
     componentSize.width = fContentCalculatedWidth;
     if (pMarginNode) {
@@ -172,8 +177,9 @@ void RelocateTableRowCells(CXFA_ContentLayoutItem* pLayoutRow,
   CFX_SizeF containerSize = CalculateContainerSpecifiedSize(
       pLayoutRow->m_pFormNode, &bContainerWidthAutoSize,
       &bContainerHeightAutoSize);
-  CXFA_Node* pMarginNode =
-      pLayoutRow->m_pFormNode->GetFirstChildByClass(XFA_Element::Margin);
+  CXFA_Margin* pMarginNode =
+      pLayoutRow->m_pFormNode->GetFirstChildByClass<CXFA_Margin>(
+          XFA_Element::Margin);
   float fLeftInset = 0;
   float fTopInset = 0;
   float fRightInset = 0;
@@ -255,8 +261,9 @@ void RelocateTableRowCells(CXFA_ContentLayoutItem* pLayoutRow,
                        &fContentCalculatedHeight);
       float fOldChildHeight = pLayoutChild->m_sSize.height;
       pLayoutChild->m_sSize.height = fContentCalculatedHeight;
-      CXFA_Node* pParaNode =
-          pLayoutChild->m_pFormNode->GetFirstChildByClass(XFA_Element::Para);
+      CXFA_Para* pParaNode =
+          pLayoutChild->m_pFormNode->GetFirstChildByClass<CXFA_Para>(
+              XFA_Element::Para);
       if (pParaNode && pLayoutChild->m_pFirstChild) {
         float fOffHeight = fContentCalculatedHeight - fOldChildHeight;
         XFA_AttributeEnum eVType =
@@ -346,8 +353,9 @@ void AddTrailerBeforeSplit(CXFA_ItemLayoutProcessor* pProcessor,
   }
 
   UpdatePendingItemLayout(pProcessor, pTrailerLayoutItem);
-  CXFA_Node* pMarginNode =
-      pProcessor->m_pFormNode->GetFirstChildByClass(XFA_Element::Margin);
+  CXFA_Margin* pMarginNode =
+      pProcessor->m_pFormNode->GetFirstChildByClass<CXFA_Margin>(
+          XFA_Element::Margin);
   float fLeftInset = 0;
   float fTopInset = 0;
   float fRightInset = 0;
@@ -413,8 +421,9 @@ void AddLeaderAfterSplit(CXFA_ItemLayoutProcessor* pProcessor,
                          CXFA_ContentLayoutItem* pLeaderLayoutItem) {
   UpdatePendingItemLayout(pProcessor, pLeaderLayoutItem);
 
-  CXFA_Node* pMarginNode =
-      pProcessor->m_pFormNode->GetFirstChildByClass(XFA_Element::Margin);
+  CXFA_Margin* pMarginNode =
+      pProcessor->m_pFormNode->GetFirstChildByClass<CXFA_Margin>(
+          XFA_Element::Margin);
   float fLeftInset = 0;
   float fRightInset = 0;
   if (pMarginNode) {
@@ -522,7 +531,8 @@ bool ExistContainerKeep(CXFA_Node* pCurNode, bool bPreFind) {
   if (!pPreContainer)
     return false;
 
-  CXFA_Node* pKeep = pCurNode->GetFirstChildByClass(XFA_Element::Keep);
+  CXFA_Keep* pKeep =
+      pCurNode->GetFirstChildByClass<CXFA_Keep>(XFA_Element::Keep);
   if (pKeep) {
     XFA_Attribute eKeepType = XFA_Attribute::Previous;
     if (!bPreFind)
@@ -538,7 +548,7 @@ bool ExistContainerKeep(CXFA_Node* pCurNode, bool bPreFind) {
     }
   }
 
-  pKeep = pPreContainer->GetFirstChildByClass(XFA_Element::Keep);
+  pKeep = pPreContainer->GetFirstChildByClass<CXFA_Keep>(XFA_Element::Keep);
   if (!pKeep)
     return false;
 
@@ -996,8 +1006,8 @@ bool FindLayoutItemSplitPos(CXFA_ContentLayoutItem* pLayoutItem,
       CXFA_Document* pDocument = pFormNode->GetDocument();
       CXFA_FFNotify* pNotify = pDocument->GetNotify();
       float fCurTopMargin = 0, fCurBottomMargin = 0;
-      CXFA_Node* pMarginNode =
-          pFormNode->GetFirstChildByClass(XFA_Element::Margin);
+      CXFA_Margin* pMarginNode =
+          pFormNode->GetFirstChildByClass<CXFA_Margin>(XFA_Element::Margin);
       if (pMarginNode && bCalculateMargin) {
         fCurTopMargin = pMarginNode->JSObject()
                             ->GetMeasure(XFA_Attribute::TopInset)
@@ -1221,8 +1231,9 @@ void CXFA_ItemLayoutProcessor::SplitLayoutItem(
   if (eLayout == XFA_AttributeEnum::Position)
     bCalculateMargin = false;
 
-  CXFA_Node* pMarginNode =
-      pLayoutItem->m_pFormNode->GetFirstChildByClass(XFA_Element::Margin);
+  CXFA_Margin* pMarginNode =
+      pLayoutItem->m_pFormNode->GetFirstChildByClass<CXFA_Margin>(
+          XFA_Element::Margin);
   if (pMarginNode && bCalculateMargin) {
     fCurTopMargin = pMarginNode->JSObject()
                         ->GetMeasure(XFA_Attribute::TopInset)
@@ -1784,8 +1795,8 @@ void CXFA_ItemLayoutProcessor::DoLayoutTableContainer(CXFA_Node* pLayoutNode) {
       m_pFormNode, &bContainerWidthAutoSize, &bContainerHeightAutoSize);
   float fContentCalculatedWidth = 0;
   float fContentCalculatedHeight = 0;
-  CXFA_Node* pMarginNode =
-      m_pFormNode->GetFirstChildByClass(XFA_Element::Margin);
+  CXFA_Margin* pMarginNode =
+      m_pFormNode->GetFirstChildByClass<CXFA_Margin>(XFA_Element::Margin);
   float fLeftInset = 0;
   float fRightInset = 0;
   if (pMarginNode) {
@@ -2184,8 +2195,8 @@ XFA_ItemLayoutProcessorResult CXFA_ItemLayoutProcessor::DoLayoutFlowedContainer(
     }
   }
 
-  CXFA_Node* pMarginNode =
-      m_pFormNode->GetFirstChildByClass(XFA_Element::Margin);
+  CXFA_Margin* pMarginNode =
+      m_pFormNode->GetFirstChildByClass<CXFA_Margin>(XFA_Element::Margin);
   float fLeftInset = 0;
   float fTopInset = 0;
   float fRightInset = 0;
@@ -2840,9 +2851,9 @@ bool CXFA_ItemLayoutProcessor::JudgeLeaderOrTrailerForOccur(
   if (!pTemplate)
     pTemplate = pFormNode;
 
-  int32_t iMax =
-      CXFA_OccurData(pTemplate->GetFirstChildByClass(XFA_Element::Occur))
-          .GetMax();
+  int32_t iMax = CXFA_OccurData(pTemplate->GetFirstChildByClass<CXFA_Occur>(
+                                    XFA_Element::Occur))
+                     .GetMax();
   if (iMax < 0)
     return true;
 
diff --git a/xfa/fxfa/parser/cxfa_layoutitem.cpp b/xfa/fxfa/parser/cxfa_layoutitem.cpp
index 02602fd55d..2dfd1efc94 100644
--- a/xfa/fxfa/parser/cxfa_layoutitem.cpp
+++ b/xfa/fxfa/parser/cxfa_layoutitem.cpp
@@ -9,6 +9,7 @@
 #include "xfa/fxfa/cxfa_ffnotify.h"
 #include "xfa/fxfa/parser/cxfa_containerlayoutitem.h"
 #include "xfa/fxfa/parser/cxfa_contentlayoutitem.h"
+#include "xfa/fxfa/parser/cxfa_margin.h"
 #include "xfa/fxfa/parser/cxfa_measurement.h"
 #include "xfa/fxfa/parser/cxfa_node.h"
 
@@ -73,8 +74,9 @@ CFX_RectF CXFA_LayoutItem::GetRect(bool bRelative) const {
        pLayoutItem = pLayoutItem->m_pParent) {
     if (CXFA_ContentLayoutItem* pContent = pLayoutItem->AsContentLayoutItem()) {
       sPos += pContent->m_sPos;
-      CXFA_Node* pMarginNode =
-          pLayoutItem->m_pFormNode->GetFirstChildByClass(XFA_Element::Margin);
+      CXFA_Margin* pMarginNode =
+          pLayoutItem->m_pFormNode->GetFirstChildByClass<CXFA_Margin>(
+              XFA_Element::Margin);
       if (pMarginNode) {
         sPos += CFX_PointF(pMarginNode->JSObject()
                                ->GetMeasure(XFA_Attribute::LeftInset)
diff --git a/xfa/fxfa/parser/cxfa_layoutpagemgr.cpp b/xfa/fxfa/parser/cxfa_layoutpagemgr.cpp
index 21b3aca235..5cd7b76ddc 100644
--- a/xfa/fxfa/parser/cxfa_layoutpagemgr.cpp
+++ b/xfa/fxfa/parser/cxfa_layoutpagemgr.cpp
@@ -21,6 +21,9 @@
 #include "xfa/fxfa/parser/cxfa_node.h"
 #include "xfa/fxfa/parser/cxfa_nodeiteratortemplate.h"
 #include "xfa/fxfa/parser/cxfa_object.h"
+#include "xfa/fxfa/parser/cxfa_occur.h"
+#include "xfa/fxfa/parser/cxfa_pageset.h"
+#include "xfa/fxfa/parser/cxfa_subform.h"
 #include "xfa/fxfa/parser/cxfa_traversestrategy_contentareacontainerlayoutitem.h"
 #include "xfa/fxfa/parser/cxfa_traversestrategy_layoutitem.h"
 #include "xfa/fxfa/parser/cxfa_traversestrategy_xfacontainernode.h"
@@ -312,7 +315,8 @@ bool CXFA_LayoutPageMgr::InitLayoutPage(CXFA_Node* pFormNode) {
        pPageArea = pPageArea->GetNodeItem(XFA_NODEITEM_NextSibling)) {
     if (pPageArea->GetElementType() == XFA_Element::PageArea) {
       iCount++;
-      if (pPageArea->GetFirstChildByClass(XFA_Element::ContentArea))
+      if (pPageArea->GetFirstChildByClass<CXFA_ContentArea>(
+              XFA_Element::ContentArea))
         return true;
     }
   }
@@ -390,11 +394,12 @@ bool CXFA_LayoutPageMgr::PrepareFirstPage(CXFA_Node* pRootSubform) {
       break;
 
     bProBreakBefore = true;
-    pRootSubform = pRootSubform->GetFirstChildByClass(XFA_Element::Subform);
+    pRootSubform =
+        pRootSubform->GetFirstChildByClass<CXFA_Subform>(XFA_Element::Subform);
     while (pRootSubform &&
            !XFA_ItemLayoutProcessor_IsTakingSpace(pRootSubform)) {
-      pRootSubform =
-          pRootSubform->GetNextSameClassSibling(XFA_Element::Subform);
+      pRootSubform = pRootSubform->GetNextSameClassSibling<CXFA_Subform>(
+          XFA_Element::Subform);
     }
   }
   CXFA_Node* pLeader;
@@ -820,8 +825,8 @@ bool CXFA_LayoutPageMgr::ExecuteBreakBeforeOrAfter(
       CXFA_Node* pContainer = pFormNode->GetTemplateNode();
       bool bStartNew =
           pCurNode->JSObject()->GetInteger(XFA_Attribute::StartNew) != 0;
-      CXFA_Script* pScript = static_cast<CXFA_Script*>(
-          pCurNode->GetFirstChildByClass(XFA_Element::Script));
+      CXFA_Script* pScript =
+          pCurNode->GetFirstChildByClass<CXFA_Script>(XFA_Element::Script);
       if (pScript && !RunBreakTestScript(pScript))
         return false;
 
@@ -1143,7 +1148,8 @@ bool CXFA_LayoutPageMgr::FindPageAreaFromPageSet_Ordered(
     if (it != m_pPageSetMap.end())
       iPageSetCount = it->second;
     int32_t iMax = -1;
-    CXFA_Node* pOccurNode = pPageSet->GetFirstChildByClass(XFA_Element::Occur);
+    CXFA_Node* pOccurNode =
+        pPageSet->GetFirstChildByClass<CXFA_Occur>(XFA_Element::Occur);
     if (pOccurNode) {
       pdfium::Optional<int32_t> ret =
           pOccurNode->JSObject()->TryInteger(XFA_Attribute::Max, false);
@@ -1162,7 +1168,8 @@ bool CXFA_LayoutPageMgr::FindPageAreaFromPageSet_Ordered(
        pCurrentNode = pCurrentNode->GetNodeItem(XFA_NODEITEM_NextSibling)) {
     if (pCurrentNode->GetElementType() == XFA_Element::PageArea) {
       if ((pTargetPageArea == pCurrentNode || !pTargetPageArea)) {
-        if (!pCurrentNode->GetFirstChildByClass(XFA_Element::ContentArea)) {
+        if (!pCurrentNode->GetFirstChildByClass<CXFA_ContentArea>(
+                XFA_Element::ContentArea)) {
           if (pTargetPageArea == pCurrentNode) {
             CreateMinPageRecord(pCurrentNode, true);
             pTargetPageArea = nullptr;
@@ -1175,7 +1182,8 @@ bool CXFA_LayoutPageMgr::FindPageAreaFromPageSet_Ordered(
           AddPageAreaLayoutItem(pNewRecord, pCurrentNode);
           if (!pTargetContentArea) {
             pTargetContentArea =
-                pCurrentNode->GetFirstChildByClass(XFA_Element::ContentArea);
+                pCurrentNode->GetFirstChildByClass<CXFA_ContentArea>(
+                    XFA_Element::ContentArea);
           }
           AddContentAreaLayoutItem(pNewRecord, pTargetContentArea);
         }
@@ -1238,8 +1246,9 @@ bool CXFA_LayoutPageMgr::FindPageAreaFromPageSet_SimplexDuplex(
         }
         CXFA_ContainerRecord* pNewRecord = CreateContainerRecord();
         AddPageAreaLayoutItem(pNewRecord, pCurrentNode);
-        AddContentAreaLayoutItem(pNewRecord, pCurrentNode->GetFirstChildByClass(
-                                                 XFA_Element::ContentArea));
+        AddContentAreaLayoutItem(
+            pNewRecord, pCurrentNode->GetFirstChildByClass<CXFA_ContentArea>(
+                            XFA_Element::ContentArea));
         pPreferredPageArea = pCurrentNode;
         return false;
       }
@@ -1255,7 +1264,8 @@ bool CXFA_LayoutPageMgr::FindPageAreaFromPageSet_SimplexDuplex(
         return false;
       }
       if ((pTargetPageArea == pCurrentNode || !pTargetPageArea)) {
-        if (!pCurrentNode->GetFirstChildByClass(XFA_Element::ContentArea)) {
+        if (!pCurrentNode->GetFirstChildByClass<CXFA_ContentArea>(
+                XFA_Element::ContentArea)) {
           if (pTargetPageArea == pCurrentNode) {
             CXFA_ContainerRecord* pNewRecord = CreateContainerRecord();
             AddPageAreaLayoutItem(pNewRecord, pCurrentNode);
@@ -1275,8 +1285,9 @@ bool CXFA_LayoutPageMgr::FindPageAreaFromPageSet_SimplexDuplex(
       } else if (pTargetPageArea && !MatchPageAreaOddOrEven(pTargetPageArea)) {
         CXFA_ContainerRecord* pNewRecord = CreateContainerRecord();
         AddPageAreaLayoutItem(pNewRecord, pCurrentNode);
-        AddContentAreaLayoutItem(pNewRecord, pCurrentNode->GetFirstChildByClass(
-                                                 XFA_Element::ContentArea));
+        AddContentAreaLayoutItem(
+            pNewRecord, pCurrentNode->GetFirstChildByClass<CXFA_ContentArea>(
+                            XFA_Element::ContentArea));
       }
     } else if (pCurrentNode->GetElementType() == XFA_Element::PageSet) {
       if (FindPageAreaFromPageSet_SimplexDuplex(
@@ -1300,8 +1311,8 @@ bool CXFA_LayoutPageMgr::FindPageAreaFromPageSet_SimplexDuplex(
     CXFA_ContainerRecord* pNewRecord = CreateContainerRecord();
     AddPageAreaLayoutItem(pNewRecord, pCurPageArea);
     if (!pTargetContentArea) {
-      pTargetContentArea =
-          pCurPageArea->GetFirstChildByClass(XFA_Element::ContentArea);
+      pTargetContentArea = pCurPageArea->GetFirstChildByClass<CXFA_ContentArea>(
+          XFA_Element::ContentArea);
     }
     AddContentAreaLayoutItem(pNewRecord, pTargetContentArea);
   }
@@ -1341,7 +1352,7 @@ CXFA_Node* CXFA_LayoutPageMgr::GetNextAvailPageArea(
     if (IsPageSetRootOrderedOccurrence()) {
       int32_t iMax = -1;
       CXFA_Node* pOccurNode =
-          m_pCurPageArea->GetFirstChildByClass(XFA_Element::Occur);
+          m_pCurPageArea->GetFirstChildByClass<CXFA_Occur>(XFA_Element::Occur);
       if (pOccurNode) {
         pdfium::Optional<int32_t> ret =
             pOccurNode->JSObject()->TryInteger(XFA_Attribute::Max, false);
@@ -1355,7 +1366,8 @@ CXFA_Node* CXFA_LayoutPageMgr::GetNextAvailPageArea(
           AddPageAreaLayoutItem(pNewRecord, m_pCurPageArea);
           if (!pTargetContentArea) {
             pTargetContentArea =
-                m_pCurPageArea->GetFirstChildByClass(XFA_Element::ContentArea);
+                m_pCurPageArea->GetFirstChildByClass<CXFA_ContentArea>(
+                    XFA_Element::ContentArea);
           }
           AddContentAreaLayoutItem(pNewRecord, pTargetContentArea);
         }
@@ -1397,8 +1409,8 @@ bool CXFA_LayoutPageMgr::GetNextContentArea(CXFA_Node* pContentArea) {
   CXFA_Node* pCurContentNode =
       GetCurrentContainerRecord()->pCurContentArea->m_pFormNode;
   if (!pContentArea) {
-    pContentArea =
-        pCurContentNode->GetNextSameClassSibling(XFA_Element::ContentArea);
+    pContentArea = pCurContentNode->GetNextSameClassSibling<CXFA_ContentArea>(
+        XFA_Element::ContentArea);
     if (!pContentArea)
       return false;
   } else {
@@ -1449,7 +1461,8 @@ int32_t CXFA_LayoutPageMgr::CreateMinPageRecord(CXFA_Node* pPageArea,
 
   int32_t iMin = 0;
   pdfium::Optional<int32_t> ret;
-  CXFA_Node* pOccurNode = pPageArea->GetFirstChildByClass(XFA_Element::Occur);
+  CXFA_Node* pOccurNode =
+      pPageArea->GetFirstChildByClass<CXFA_Occur>(XFA_Element::Occur);
   if (pOccurNode) {
     ret = pOccurNode->JSObject()->TryInteger(XFA_Attribute::Min, false);
     if (ret)
@@ -1459,8 +1472,8 @@ int32_t CXFA_LayoutPageMgr::CreateMinPageRecord(CXFA_Node* pPageArea,
   if (!ret && !bTargetPageArea)
     return iMin;
 
-  CXFA_Node* pContentArea =
-      pPageArea->GetFirstChildByClass(XFA_Element::ContentArea);
+  CXFA_Node* pContentArea = pPageArea->GetFirstChildByClass<CXFA_ContentArea>(
+      XFA_Element::ContentArea);
   if (iMin < 1 && bTargetPageArea && !pContentArea)
     iMin = 1;
 
@@ -1489,7 +1502,8 @@ void CXFA_LayoutPageMgr::CreateMinPageSetRecord(CXFA_Node* pPageSet,
   if (bCreateAll)
     iCurSetCount = 0;
 
-  CXFA_Node* pOccurNode = pPageSet->GetFirstChildByClass(XFA_Element::Occur);
+  CXFA_Node* pOccurNode =
+      pPageSet->GetFirstChildByClass<CXFA_Occur>(XFA_Element::Occur);
   if (!pOccurNode)
     return;
 
@@ -1545,8 +1559,8 @@ bool CXFA_LayoutPageMgr::GetNextAvailContentHeight(float fChildHeight) {
   if (!pCurContentNode)
     return false;
 
-  pCurContentNode =
-      pCurContentNode->GetNextSameClassSibling(XFA_Element::ContentArea);
+  pCurContentNode = pCurContentNode->GetNextSameClassSibling<CXFA_ContentArea>(
+      XFA_Element::ContentArea);
   if (pCurContentNode) {
     float fNextContentHeight = pCurContentNode->JSObject()
                                    ->GetMeasure(XFA_Attribute::H)
@@ -1555,7 +1569,8 @@ bool CXFA_LayoutPageMgr::GetNextAvailContentHeight(float fChildHeight) {
   }
 
   CXFA_Node* pPageNode = GetCurrentContainerRecord()->pCurPageArea->m_pFormNode;
-  CXFA_Node* pOccurNode = pPageNode->GetFirstChildByClass(XFA_Element::Occur);
+  CXFA_Node* pOccurNode =
+      pPageNode->GetFirstChildByClass<CXFA_Occur>(XFA_Element::Occur);
   int32_t iMax = 0;
   pdfium::Optional<int32_t> ret;
   if (pOccurNode) {
@@ -1582,7 +1597,8 @@ bool CXFA_LayoutPageMgr::GetNextAvailContentHeight(float fChildHeight) {
       }
       if (pNextPage) {
         CXFA_Node* pContentArea =
-            pNextPage->GetFirstChildByClass(XFA_Element::ContentArea);
+            pNextPage->GetFirstChildByClass<CXFA_ContentArea>(
+                XFA_Element::ContentArea);
         if (pContentArea) {
           float fNextContentHeight = pContentArea->JSObject()
                                          ->GetMeasure(XFA_Attribute::H)
@@ -1595,8 +1611,8 @@ bool CXFA_LayoutPageMgr::GetNextAvailContentHeight(float fChildHeight) {
     }
   }
 
-  CXFA_Node* pContentArea =
-      pPageNode->GetFirstChildByClass(XFA_Element::ContentArea);
+  CXFA_Node* pContentArea = pPageNode->GetFirstChildByClass<CXFA_ContentArea>(
+      XFA_Element::ContentArea);
   float fNextContentHeight = pContentArea->JSObject()
                                  ->GetMeasure(XFA_Attribute::H)
                                  .ToUnit(XFA_Unit::Pt);
@@ -1830,7 +1846,7 @@ void CXFA_LayoutPageMgr::MergePageSetContents() {
       CXFA_Node* pFormToplevelSubform =
           pDocument->GetXFAObject(XFA_HASHCODE_Form)
               ->AsNode()
-              ->GetFirstChildByClass(XFA_Element::Subform);
+              ->GetFirstChildByClass<CXFA_Subform>(XFA_Element::Subform);
       pFormToplevelSubform->InsertChild(pPendingPageSet, nullptr);
     }
     pDocument->DataMerge_UpdateBindingRelations(pPendingPageSet);
@@ -1840,7 +1856,7 @@ void CXFA_LayoutPageMgr::MergePageSetContents() {
   CXFA_Node* pPageSet = GetRootLayoutItem()->m_pFormNode;
   while (pPageSet) {
     CXFA_Node* pNextPageSet =
-        pPageSet->GetNextSameClassSibling(XFA_Element::PageSet);
+        pPageSet->GetNextSameClassSibling<CXFA_PageSet>(XFA_Element::PageSet);
     CXFA_NodeIteratorTemplate<CXFA_Node, CXFA_TraverseStrategy_XFANode>
         sIterator(pPageSet);
     CXFA_Node* pNode = sIterator.GetCurrent();
@@ -2002,7 +2018,8 @@ void CXFA_LayoutPageMgr::PrepareLayout() {
     }
     while (pPageSetFormNode) {
       CXFA_Node* pNextPageSet =
-          pPageSetFormNode->GetNextSameClassSibling(XFA_Element::PageSet);
+          pPageSetFormNode->GetNextSameClassSibling<CXFA_PageSet>(
+              XFA_Element::PageSet);
       pPageSetFormNode->GetNodeItem(XFA_NODEITEM_Parent)
           ->RemoveChild(pPageSetFormNode, false);
       pRootLayoutItem->m_pFormNode->GetDocument()->m_pPendingPageSet.push_back(
diff --git a/xfa/fxfa/parser/cxfa_layoutprocessor.cpp b/xfa/fxfa/parser/cxfa_layoutprocessor.cpp
index 37906ce297..36caa0c0a6 100644
--- a/xfa/fxfa/parser/cxfa_layoutprocessor.cpp
+++ b/xfa/fxfa/parser/cxfa_layoutprocessor.cpp
@@ -15,6 +15,7 @@
 #include "xfa/fxfa/parser/cxfa_localemgr.h"
 #include "xfa/fxfa/parser/cxfa_measurement.h"
 #include "xfa/fxfa/parser/cxfa_node.h"
+#include "xfa/fxfa/parser/cxfa_subform.h"
 #include "xfa/fxfa/parser/xfa_document_datamerger_imp.h"
 #include "xfa/fxfa/parser/xfa_utils.h"
 
@@ -38,8 +39,8 @@ int32_t CXFA_LayoutProcessor::StartLayout(bool bForceRestart) {
   if (!pFormPacketNode)
     return -1;
 
-  CXFA_Node* pFormRoot =
-      pFormPacketNode->GetFirstChildByClass(XFA_Element::Subform);
+  CXFA_Subform* pFormRoot =
+      pFormPacketNode->GetFirstChildByClass<CXFA_Subform>(XFA_Element::Subform);
   if (!pFormRoot)
     return -1;
 
diff --git a/xfa/fxfa/parser/cxfa_localemgr.cpp b/xfa/fxfa/parser/cxfa_localemgr.cpp
index e7aa09b52d..323a63dd72 100644
--- a/xfa/fxfa/parser/cxfa_localemgr.cpp
+++ b/xfa/fxfa/parser/cxfa_localemgr.cpp
@@ -16,8 +16,12 @@
 #include "core/fxcodec/fx_codec.h"
 #include "core/fxcrt/xml/cxml_element.h"
 #include "third_party/base/ptr_util.h"
+#include "xfa/fxfa/parser/cxfa_acrobat.h"
+#include "xfa/fxfa/parser/cxfa_common.h"
+#include "xfa/fxfa/parser/cxfa_locale.h"
 #include "xfa/fxfa/parser/cxfa_node.h"
 #include "xfa/fxfa/parser/cxfa_nodelocale.h"
+#include "xfa/fxfa/parser/cxfa_present.h"
 #include "xfa/fxfa/parser/cxfa_xmllocale.h"
 #include "xfa/fxfa/parser/xfa_utils.h"
 
@@ -1225,17 +1229,19 @@ WideStringView CXFA_LocaleMgr::GetConfigLocaleName(CXFA_Node* pConfig) {
     m_wsConfigLocale.clear();
     if (pConfig) {
       CXFA_Node* pChildfConfig =
-          pConfig->GetFirstChildByClass(XFA_Element::Acrobat);
+          pConfig->GetFirstChildByClass<CXFA_Acrobat>(XFA_Element::Acrobat);
       if (!pChildfConfig) {
-        pChildfConfig = pConfig->GetFirstChildByClass(XFA_Element::Present);
+        pChildfConfig =
+            pConfig->GetFirstChildByClass<CXFA_Present>(XFA_Element::Present);
       }
-      CXFA_Node* pCommon =
-          pChildfConfig
-              ? pChildfConfig->GetFirstChildByClass(XFA_Element::Common)
+      CXFA_Common* pCommon =
+          pChildfConfig ? pChildfConfig->GetFirstChildByClass<CXFA_Common>(
+                              XFA_Element::Common)
+                        : nullptr;
+      CXFA_Locale* pLocale =
+          pCommon
+              ? pCommon->GetFirstChildByClass<CXFA_Locale>(XFA_Element::Locale)
               : nullptr;
-      CXFA_Node* pLocale =
-          pCommon ? pCommon->GetFirstChildByClass(XFA_Element::Locale)
-                  : nullptr;
       if (pLocale) {
         m_wsConfigLocale = pLocale->JSObject()
                                ->TryCData(XFA_Attribute::Value, false)
diff --git a/xfa/fxfa/parser/cxfa_node.cpp b/xfa/fxfa/parser/cxfa_node.cpp
index 195af08bf7..3d05b53bfd 100644
--- a/xfa/fxfa/parser/cxfa_node.cpp
+++ b/xfa/fxfa/parser/cxfa_node.cpp
@@ -30,11 +30,14 @@
 #include "xfa/fxfa/parser/cxfa_arraynodelist.h"
 #include "xfa/fxfa/parser/cxfa_attachnodelist.h"
 #include "xfa/fxfa/parser/cxfa_document.h"
+#include "xfa/fxfa/parser/cxfa_keep.h"
 #include "xfa/fxfa/parser/cxfa_layoutprocessor.h"
 #include "xfa/fxfa/parser/cxfa_measurement.h"
 #include "xfa/fxfa/parser/cxfa_nodeiteratortemplate.h"
+#include "xfa/fxfa/parser/cxfa_occur.h"
 #include "xfa/fxfa/parser/cxfa_occurdata.h"
 #include "xfa/fxfa/parser/cxfa_simple_parser.h"
+#include "xfa/fxfa/parser/cxfa_subform.h"
 #include "xfa/fxfa/parser/cxfa_traversestrategy_xfacontainernode.h"
 #include "xfa/fxfa/parser/xfa_basic_data.h"
 #include "xfa/fxfa/parser/xfa_utils.h"
@@ -621,7 +624,8 @@ CXFA_WidgetData* CXFA_Node::GetContainerWidgetData() {
 
 bool CXFA_Node::GetLocaleName(WideString& wsLocaleName) {
   CXFA_Node* pForm = GetDocument()->GetXFAObject(XFA_HASHCODE_Form)->AsNode();
-  CXFA_Node* pTopSubform = pForm->GetFirstChildByClass(XFA_Element::Subform);
+  CXFA_Subform* pTopSubform =
+      pForm->GetFirstChildByClass<CXFA_Subform>(XFA_Element::Subform);
   ASSERT(pTopSubform);
 
   CXFA_Node* pLocaleNode = this;
@@ -658,7 +662,7 @@ bool CXFA_Node::GetLocaleName(WideString& wsLocaleName) {
 }
 
 XFA_AttributeEnum CXFA_Node::GetIntact() {
-  CXFA_Node* pKeep = GetFirstChildByClass(XFA_Element::Keep);
+  CXFA_Keep* pKeep = GetFirstChildByClass<CXFA_Keep>(XFA_Element::Keep);
   XFA_AttributeEnum eLayoutType = JSObject()
                                       ->TryEnum(XFA_Attribute::Layout, true)
                                       .value_or(XFA_AttributeEnum::Position);
@@ -681,8 +685,8 @@ XFA_AttributeEnum CXFA_Node::GetIntact() {
             return XFA_AttributeEnum::ContentArea;
           }
 
-          CXFA_Node* pNode =
-              pPreviewRow->GetFirstChildByClass(XFA_Element::Keep);
+          CXFA_Keep* pNode =
+              pPreviewRow->GetFirstChildByClass<CXFA_Keep>(XFA_Element::Keep);
           pdfium::Optional<XFA_AttributeEnum> ret;
           if (pNode)
             ret = pNode->JSObject()->TryEnum(XFA_Attribute::Next, false);
@@ -983,7 +987,7 @@ CXFA_Node* CXFA_Node::GetFirstChildByName(uint32_t dwNameHash) const {
   return nullptr;
 }
 
-CXFA_Node* CXFA_Node::GetFirstChildByClass(XFA_Element eType) const {
+CXFA_Node* CXFA_Node::GetFirstChildByClassInternal(XFA_Element eType) const {
   for (CXFA_Node* pNode = GetNodeItem(XFA_NODEITEM_FirstChild); pNode;
        pNode = pNode->GetNodeItem(XFA_NODEITEM_NextSibling)) {
     if (pNode->GetElementType() == eType) {
@@ -1003,12 +1007,12 @@ CXFA_Node* CXFA_Node::GetNextSameNameSibling(uint32_t dwNameHash) const {
   return nullptr;
 }
 
-CXFA_Node* CXFA_Node::GetNextSameNameSibling(
+CXFA_Node* CXFA_Node::GetNextSameNameSiblingInternal(
     const WideStringView& wsNodeName) const {
   return GetNextSameNameSibling(FX_HashCode_GetW(wsNodeName, false));
 }
 
-CXFA_Node* CXFA_Node::GetNextSameClassSibling(XFA_Element eType) const {
+CXFA_Node* CXFA_Node::GetNextSameClassSiblingInternal(XFA_Element eType) const {
   for (CXFA_Node* pNode = GetNodeItem(XFA_NODEITEM_NextSibling); pNode;
        pNode = pNode->GetNodeItem(XFA_NODEITEM_NextSibling)) {
     if (pNode->GetElementType() == eType) {
@@ -1064,7 +1068,7 @@ CXFA_Node* CXFA_Node::GetInstanceMgrOfSubform() {
 }
 
 CXFA_Node* CXFA_Node::GetOccurNode() {
-  return GetFirstChildByClass(XFA_Element::Occur);
+  return GetFirstChildByClass<CXFA_Occur>(XFA_Element::Occur);
 }
 
 bool CXFA_Node::HasFlag(XFA_NodeFlag dwFlag) const {
diff --git a/xfa/fxfa/parser/cxfa_node.h b/xfa/fxfa/parser/cxfa_node.h
index c2c7605e85..c9f1505f2e 100644
--- a/xfa/fxfa/parser/cxfa_node.h
+++ b/xfa/fxfa/parser/cxfa_node.h
@@ -183,12 +183,23 @@ class CXFA_Node : public CXFA_Object {
   CXFA_WidgetData* GetContainerWidgetData();
   bool GetLocaleName(WideString& wsLocaleName);
   XFA_AttributeEnum GetIntact();
+
   CXFA_Node* GetFirstChildByName(const WideStringView& wsNodeName) const;
   CXFA_Node* GetFirstChildByName(uint32_t dwNodeNameHash) const;
-  CXFA_Node* GetFirstChildByClass(XFA_Element eType) const;
+  template <typename T>
+  T* GetFirstChildByClass(XFA_Element eType) const {
+    return static_cast<T*>(GetFirstChildByClassInternal(eType));
+  }
   CXFA_Node* GetNextSameNameSibling(uint32_t dwNodeNameHash) const;
-  CXFA_Node* GetNextSameNameSibling(const WideStringView& wsNodeName) const;
-  CXFA_Node* GetNextSameClassSibling(XFA_Element eType) const;
+  template <typename T>
+  T* GetNextSameNameSibling(const WideStringView& wsNodeName) const {
+    return static_cast<T*>(GetNextSameNameSiblingInternal(wsNodeName));
+  }
+  template <typename T>
+  T* GetNextSameClassSibling(XFA_Element eType) const {
+    return static_cast<T*>(GetNextSameClassSiblingInternal(eType));
+  }
+
   int32_t GetNodeSameNameIndex() const;
   int32_t GetNodeSameClassIndex() const;
   CXFA_Node* GetInstanceMgrOfSubform();
@@ -233,6 +244,10 @@ class CXFA_Node : public CXFA_Object {
   CXFA_Node* GetChildInternal(int32_t index,
                               XFA_Element eType,
                               bool bOnlyChild);
+  CXFA_Node* GetFirstChildByClassInternal(XFA_Element eType) const;
+  CXFA_Node* GetNextSameNameSiblingInternal(
+      const WideStringView& wsNodeName) const;
+  CXFA_Node* GetNextSameClassSiblingInternal(XFA_Element eType) const;
 
   const PropertyData* const m_Properties;
   const AttributeData* const m_Attributes;
diff --git a/xfa/fxfa/parser/cxfa_nodelocale.cpp b/xfa/fxfa/parser/cxfa_nodelocale.cpp
index e7bba363cf..5031216de9 100644
--- a/xfa/fxfa/parser/cxfa_nodelocale.cpp
+++ b/xfa/fxfa/parser/cxfa_nodelocale.cpp
@@ -165,8 +165,8 @@ WideString CXFA_NodeLocale::GetCalendarSymbol(XFA_Element eElement,
   if (!pCalendar)
     return WideString();
 
-  CXFA_Node* pNode = pCalendar->GetFirstChildByClass(eElement);
-  for (; pNode; pNode = pNode->GetNextSameClassSibling(eElement)) {
+  CXFA_Node* pNode = pCalendar->GetFirstChildByClass<CXFA_Node>(eElement);
+  for (; pNode; pNode = pNode->GetNextSameClassSibling<CXFA_Node>(eElement)) {
     if (pNode->JSObject()->GetBoolean(XFA_Attribute::Abbr) == bAbbr) {
       CXFA_Node* pSymbol =
           pNode->GetChild<CXFA_Node>(index, XFA_Element::Unknown, false);
diff --git a/xfa/fxfa/parser/cxfa_occurdata.h b/xfa/fxfa/parser/cxfa_occurdata.h
index 7c90a1993b..1b4d600875 100644
--- a/xfa/fxfa/parser/cxfa_occurdata.h
+++ b/xfa/fxfa/parser/cxfa_occurdata.h
@@ -12,7 +12,7 @@
 #include "core/fxcrt/fx_system.h"
 #include "xfa/fxfa/parser/cxfa_datadata.h"
 
-class CXFA_Node;
+class CXFA_Occur;
 
 class CXFA_OccurData : public CXFA_DataData {
  public:
diff --git a/xfa/fxfa/parser/cxfa_simple_parser.cpp b/xfa/fxfa/parser/cxfa_simple_parser.cpp
index 5c722821cb..feafdcf38d 100644
--- a/xfa/fxfa/parser/cxfa_simple_parser.cpp
+++ b/xfa/fxfa/parser/cxfa_simple_parser.cpp
@@ -26,6 +26,8 @@
 #include "xfa/fxfa/fxfa.h"
 #include "xfa/fxfa/parser/cxfa_document.h"
 #include "xfa/fxfa/parser/cxfa_node.h"
+#include "xfa/fxfa/parser/cxfa_subform.h"
+#include "xfa/fxfa/parser/cxfa_template.h"
 #include "xfa/fxfa/parser/xfa_basic_data.h"
 #include "xfa/fxfa/parser/xfa_utils.h"
 
@@ -709,10 +711,11 @@ CXFA_Node* CXFA_SimpleParser::ParseAsXDPPacket_Form(
   pNode->JSObject()->SetCData(XFA_Attribute::Name, packet->name, false, false);
   pNode->JSObject()->SetAttribute(XFA_Attribute::Checksum,
                                   wsChecksum.AsStringView(), false);
-  CXFA_Node* pTemplateRoot =
-      m_pRootNode->GetFirstChildByClass(XFA_Element::Template);
-  CXFA_Node* pTemplateChosen =
-      pTemplateRoot ? pTemplateRoot->GetFirstChildByClass(XFA_Element::Subform)
+  CXFA_Template* pTemplateRoot =
+      m_pRootNode->GetFirstChildByClass<CXFA_Template>(XFA_Element::Template);
+  CXFA_Subform* pTemplateChosen =
+      pTemplateRoot ? pTemplateRoot->GetFirstChildByClass<CXFA_Subform>(
+                          XFA_Element::Subform)
                     : nullptr;
   bool bUseAttribute = true;
   if (pTemplateChosen &&
diff --git a/xfa/fxfa/parser/xfa_document_datamerger_imp.cpp b/xfa/fxfa/parser/xfa_document_datamerger_imp.cpp
index 22b339aba5..6b7488c4a7 100644
--- a/xfa/fxfa/parser/xfa_document_datamerger_imp.cpp
+++ b/xfa/fxfa/parser/xfa_document_datamerger_imp.cpp
@@ -15,13 +15,20 @@
 #include "fxjs/cfxjse_engine.h"
 #include "third_party/base/logging.h"
 #include "third_party/base/stl_util.h"
+#include "xfa/fxfa/parser/cxfa_bind.h"
+#include "xfa/fxfa/parser/cxfa_datagroup.h"
 #include "xfa/fxfa/parser/cxfa_document.h"
+#include "xfa/fxfa/parser/cxfa_form.h"
 #include "xfa/fxfa/parser/cxfa_items.h"
 #include "xfa/fxfa/parser/cxfa_layoutprocessor.h"
 #include "xfa/fxfa/parser/cxfa_localemgr.h"
 #include "xfa/fxfa/parser/cxfa_node.h"
 #include "xfa/fxfa/parser/cxfa_nodeiteratortemplate.h"
+#include "xfa/fxfa/parser/cxfa_occur.h"
 #include "xfa/fxfa/parser/cxfa_occurdata.h"
+#include "xfa/fxfa/parser/cxfa_pageset.h"
+#include "xfa/fxfa/parser/cxfa_subform.h"
+#include "xfa/fxfa/parser/cxfa_template.h"
 #include "xfa/fxfa/parser/cxfa_traversestrategy_xfacontainernode.h"
 #include "xfa/fxfa/parser/cxfa_traversestrategy_xfanode.h"
 #include "xfa/fxfa/parser/cxfa_value.h"
@@ -402,10 +409,12 @@ CXFA_Node* ScopeMatchGlobalBinding(CXFA_Node* pDataScope,
       return pDataChild;
     }
 
-    for (CXFA_Node* pDataChild =
-             pCurDataScope->GetFirstChildByClass(XFA_Element::DataGroup);
-         pDataChild; pDataChild = pDataChild->GetNextSameClassSibling(
-                         XFA_Element::DataGroup)) {
+    for (CXFA_DataGroup* pDataChild =
+             pCurDataScope->GetFirstChildByClass<CXFA_DataGroup>(
+                 XFA_Element::DataGroup);
+         pDataChild;
+         pDataChild = pDataChild->GetNextSameClassSibling<CXFA_DataGroup>(
+             XFA_Element::DataGroup)) {
       CXFA_Node* pDataNode = ScopeMatchGlobalBinding(pDataChild, dwNameHash,
                                                      eMatchDataNodeType, false);
       if (pDataNode)
@@ -588,8 +597,8 @@ CXFA_Node* FindMatchingDataNode(
         continue;
     }
 
-    CXFA_Node* pTemplateNodeOccur =
-        pCurTemplateNode->GetFirstChildByClass(XFA_Element::Occur);
+    CXFA_Occur* pTemplateNodeOccur =
+        pCurTemplateNode->GetFirstChildByClass<CXFA_Occur>(XFA_Element::Occur);
     if (pTemplateNodeOccur) {
       int32_t iMin;
       int32_t iMax;
@@ -602,8 +611,8 @@ CXFA_Node* FindMatchingDataNode(
       }
     }
 
-    CXFA_Node* pTemplateNodeBind =
-        pCurTemplateNode->GetFirstChildByClass(XFA_Element::Bind);
+    CXFA_Bind* pTemplateNodeBind =
+        pCurTemplateNode->GetFirstChildByClass<CXFA_Bind>(XFA_Element::Bind);
     XFA_AttributeEnum eMatch =
         pTemplateNodeBind
             ? pTemplateNodeBind->JSObject()->GetEnum(XFA_Attribute::Match)
@@ -719,14 +728,16 @@ CXFA_Node* CopyContainer_SubformSet(CXFA_Document* pDocument,
                                              pDocument, pFormParentNode,
                                              pTemplateNode, &subformArray)
                                        : nullptr;
-    if (CXFA_Node* pOccurTemplateNode =
-            pTemplateNode->GetFirstChildByClass(XFA_Element::Occur)) {
+    if (CXFA_Occur* pOccurTemplateNode =
+            pTemplateNode->GetFirstChildByClass<CXFA_Occur>(
+                XFA_Element::Occur)) {
       pOccurNode = pInstMgrNode ? XFA_NodeMerge_CloneOrMergeContainer(
                                       pDocument, pInstMgrNode,
                                       pOccurTemplateNode, false, nullptr)
                                 : pOccurTemplateNode;
     } else if (pInstMgrNode) {
-      pOccurNode = pInstMgrNode->GetFirstChildByClass(XFA_Element::Occur);
+      pOccurNode =
+          pInstMgrNode->GetFirstChildByClass<CXFA_Occur>(XFA_Element::Occur);
       if (pOccurNode)
         pOccurNode->ClearFlag(XFA_NodeFlag_UnusedNode);
     }
@@ -746,8 +757,10 @@ CXFA_Node* CopyContainer_SubformSet(CXFA_Document* pDocument,
   int32_t iMax = 1;
   int32_t iInit = 1;
   int32_t iMin = 1;
-  if (!bOneInstance && pOccurNode)
-    std::tie(iMin, iMax, iInit) = CXFA_OccurData(pOccurNode).GetOccurInfo();
+  if (!bOneInstance && pOccurNode) {
+    std::tie(iMin, iMax, iInit) =
+        CXFA_OccurData(static_cast<CXFA_Occur*>(pOccurNode)).GetOccurInfo();
+  }
 
   XFA_AttributeEnum eRelation =
       eType == XFA_Element::SubformSet
@@ -1090,9 +1103,10 @@ void UpdateBindingRelations(CXFA_Document* pDocument,
   if (eType == XFA_Element::Subform || eType == XFA_Element::ExclGroup ||
       eType == XFA_Element::Field) {
     CXFA_Node* pTemplateNode = pFormNode->GetTemplateNode();
-    CXFA_Node* pTemplateNodeBind =
-        pTemplateNode ? pTemplateNode->GetFirstChildByClass(XFA_Element::Bind)
-                      : nullptr;
+    CXFA_Bind* pTemplateNodeBind =
+        pTemplateNode
+            ? pTemplateNode->GetFirstChildByClass<CXFA_Bind>(XFA_Element::Bind)
+            : nullptr;
     XFA_AttributeEnum eMatch =
         pTemplateNodeBind
             ? pTemplateNodeBind->JSObject()->GetEnum(XFA_Attribute::Match)
@@ -1431,11 +1445,11 @@ void CXFA_Document::DoDataMerge() {
     pDatasetsRoot->InsertChild(pDataRoot, nullptr);
   }
 
-  CXFA_Node* pDataTopLevel =
-      pDataRoot->GetFirstChildByClass(XFA_Element::DataGroup);
+  CXFA_DataGroup* pDataTopLevel =
+      pDataRoot->GetFirstChildByClass<CXFA_DataGroup>(XFA_Element::DataGroup);
   uint32_t dwNameHash = pDataTopLevel ? pDataTopLevel->GetNameHash() : 0;
-  CXFA_Node* pTemplateRoot =
-      m_pRootNode->GetFirstChildByClass(XFA_Element::Template);
+  CXFA_Template* pTemplateRoot =
+      m_pRootNode->GetFirstChildByClass<CXFA_Template>(XFA_Element::Template);
   if (!pTemplateRoot)
     return;
 
@@ -1444,16 +1458,19 @@ void CXFA_Document::DoDataMerge() {
                       : nullptr;
   if (!pTemplateChosen ||
       pTemplateChosen->GetElementType() != XFA_Element::Subform) {
-    pTemplateChosen = pTemplateRoot->GetFirstChildByClass(XFA_Element::Subform);
+    pTemplateChosen =
+        pTemplateRoot->GetFirstChildByClass<CXFA_Subform>(XFA_Element::Subform);
   }
   if (!pTemplateChosen)
     return;
 
-  CXFA_Node* pFormRoot = m_pRootNode->GetFirstChildByClass(XFA_Element::Form);
+  CXFA_Form* pFormRoot =
+      m_pRootNode->GetFirstChildByClass<CXFA_Form>(XFA_Element::Form);
   bool bEmptyForm = false;
   if (!pFormRoot) {
     bEmptyForm = true;
-    pFormRoot = CreateNode(XFA_PacketType::Form, XFA_Element::Form);
+    pFormRoot = static_cast<CXFA_Form*>(
+        CreateNode(XFA_PacketType::Form, XFA_Element::Form));
     ASSERT(pFormRoot);
     pFormRoot->JSObject()->SetCData(XFA_Attribute::Name, L"form", false, false);
     m_pRootNode->InsertChild(pFormRoot, nullptr);
@@ -1476,8 +1493,8 @@ void CXFA_Document::DoDataMerge() {
     CFX_XMLElement* pDataTopLevelXMLNode =
         new CFX_XMLElement(wsDataTopLevelName);
 
-    pDataTopLevel =
-        CreateNode(XFA_PacketType::Datasets, XFA_Element::DataGroup);
+    pDataTopLevel = static_cast<CXFA_DataGroup*>(
+        CreateNode(XFA_PacketType::Datasets, XFA_Element::DataGroup));
     pDataTopLevel->JSObject()->SetCData(XFA_Attribute::Name, wsDataTopLevelName,
                                         false, false);
     pDataTopLevel->SetXMLMappingNode(pDataTopLevelXMLNode);
@@ -1503,12 +1520,13 @@ void CXFA_Document::DoDataMerge() {
     UpdateDataRelation(pDataRoot, pDDRoot);
 
   DataMerge_UpdateBindingRelations(pSubformSetNode);
-  CXFA_Node* pPageSetNode =
-      pSubformSetNode->GetFirstChildByClass(XFA_Element::PageSet);
+  CXFA_PageSet* pPageSetNode =
+      pSubformSetNode->GetFirstChildByClass<CXFA_PageSet>(XFA_Element::PageSet);
   while (pPageSetNode) {
     m_pPendingPageSet.push_back(pPageSetNode);
-    CXFA_Node* pNextPageSetNode =
-        pPageSetNode->GetNextSameClassSibling(XFA_Element::PageSet);
+    CXFA_PageSet* pNextPageSetNode =
+        pPageSetNode->GetNextSameClassSibling<CXFA_PageSet>(
+            XFA_Element::PageSet);
     pSubformSetNode->RemoveChild(pPageSetNode, true);
     pPageSetNode = pNextPageSetNode;
   }