feat: merge context settings, replace if_filled tag with var

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

src/django_components/node.py

@@ -1,4 +1,4 @@
-from typing import Callable
+from typing import Callable, List, NamedTuple, Optional
 
 from django.template.base import Node, NodeList, TextNode
 from django.template.defaulttags import CommentNode
@@ -15,13 +15,20 @@ def nodelist_has_content(nodelist: NodeList) -> bool:
     return False
 
 
-def walk_nodelist(nodes: NodeList, callback: Callable[[Node], None]) -> None:
+class NodeTraverse(NamedTuple):
+    node: Node
+    parent: Optional["NodeTraverse"]
+
+
+def walk_nodelist(nodes: NodeList, callback: Callable[[Node], Optional[str]]) -> None:
     """Recursively walk a NodeList, calling `callback` for each Node."""
-    node_queue = [*nodes]
+    node_queue: List[NodeTraverse] = [NodeTraverse(node=node, parent=None) for node in nodes]
     while len(node_queue):
-        node: Node = node_queue.pop()
-        callback(node)
-        node_queue.extend(get_node_children(node))
+        traverse = node_queue.pop()
+        callback(traverse)
+        child_nodes = get_node_children(traverse.node)
+        child_traverses = [NodeTraverse(node=child_node, parent=traverse) for child_node in child_nodes]
+        node_queue.extend(child_traverses)
 
 
 def get_node_children(node: Node) -> NodeList: