* Modified TDOMNodeList. It now has a fixed BuildList procedure which iterates descendant nodes,

  calling NodeFilter for each node. The NodeFilter return value determines whether the node will
  be added to the list, and whether node's children should be recursively iterated.
  This considerably simplifies creating TDOMNodeList descendants, as they no longer need to mess
  with the class internals (FRevision, FList, etc).

git-svn-id: trunk@13227 -

packages/fcl-xml/src/dom.pp

@@ -290,6 +290,8 @@ type
 //   NodeList
 // -------------------------------------------------------
 
+  TFilterResult = (frFalse, frNorecurseFalse, frTrue, frNorecurseTrue);
+
   TDOMNodeList = class(TObject)
   protected
     FNode: TDOMNode;
@@ -297,6 +299,8 @@ type
     FList: TFPList;
     function GetCount: LongWord;
     function GetItem(index: LongWord): TDOMNode;
+    function NodeFilter(aNode: TDOMNode): TFilterResult; virtual;
+    // now deprecated in favor of NodeFilter
     procedure BuildList; virtual;
   public
     constructor Create(ANode: TDOMNode);
@@ -313,7 +317,7 @@ type
     filter: DOMString;
     FNamespaceFilter: DOMString;
     UseFilter: Boolean;
-    procedure BuildList; override;
+    function NodeFilter(aNode: TDOMNode): TFilterResult; override;
   public
     constructor Create(ANode: TDOMNode; const AFilter: DOMString); overload;
     constructor Create(ANode: TDOMNode; const nsURI, localName: DOMString); overload;
@@ -1412,18 +1416,43 @@ begin
   inherited Destroy;
 end;
 
+function TDOMNodeList.NodeFilter(aNode: TDOMNode): TFilterResult;
+begin
+// accept all nodes but don't allow recursion
+  Result := frNorecurseTrue;
+end;
+
 procedure TDOMNodeList.BuildList;
 var
-  Child: TDOMNode;
+  current, next: TDOMNode;
+  res: TFilterResult;
 begin
   FList.Clear;
   FRevision := FNode.GetRevision; // refresh
 
-  Child := FNode.FirstChild;
-  while Assigned(Child) do
+  current := FNode.FirstChild;
+
+  while Assigned(current) do
   begin
-    FList.Add(Child);
-    Child := Child.NextSibling;
+    res := NodeFilter(current);
+    if res in [frTrue, frNorecurseTrue] then
+      FList.Add(current);
+
+    next := nil;
+    if res in [frTrue, frFalse] then
+      next := current.FirstChild;
+
+    if next = nil then
+    begin
+      while current <> FNode do
+      begin
+        next := current.NextSibling;
+        if Assigned(next) then
+          Break;
+        current := current.ParentNode;
+      end;
+    end;
+    current := next;
   end;
 end;
 
@@ -1464,33 +1493,13 @@ begin
 end;
 
 // TODO: namespace support here
-procedure TDOMElementList.BuildList;
-var
-  Child: TDOMNode;
+function TDOMElementList.NodeFilter(aNode: TDOMNode): TFilterResult;
 begin
-  FList.Clear;
-  FRevision := FNode.GetRevision; // refresh
-
-  Child := FNode.FirstChild;
-  while Assigned(Child) and (Child <> FNode) do
-  begin
-    if (Child.NodeType = ELEMENT_NODE) and (not UseFilter or (TDOMElement(Child).TagName = filter)) then
-          FList.Add(Child);
-    // recursive track node hierarchy  
-    if Assigned(Child.FirstChild) then
-      Child := Child.FirstChild
-    else
-      if Assigned(Child.NextSibling) then
-        Child := Child.NextSibling
-      else
-      begin
-         Child := Child.ParentNode;
-         while Assigned(Child) and (Child <> FNode) and not Assigned(Child.NextSibling) do
-           Child := Child.ParentNode;
-         if Assigned(Child) and (Child <> FNode) then
-            Child := Child.NextSibling;
-      end;
-  end;
+  if (aNode.NodeType = ELEMENT_NODE) and
+    (not UseFilter or (TDOMElement(aNode).TagName = Filter)) then
+    Result := frTrue
+  else
+    Result := frFalse;
 end;