Try load chunk data.

tools/editortool/map/chunkdata.py

@@ -0,0 +1,53 @@
+import json
+import os
+from dusk.event import Event
+
+class ChunkData:
+  def __init__(self, mapData, x, y, z):
+    self.mapData = mapData
+    self.x = x
+    self.y = y
+    self.z = z
+    self.current = {}
+    self.original = {}
+    self.onChunkData = Event()
+
+  def load(self):
+    fname = self.getFilename()
+    if not fname or not os.path.exists(fname):
+      self.new()
+      return
+    try:
+      with open(fname, 'r') as f:
+        self.current = json.load(f)
+      self.original = json.loads(json.dumps(self.current))  # Deep copy
+      self.onChunkData.invoke(self.current)
+    except Exception as e:
+      raise RuntimeError(f"Failed to load chunk file: {e}")
+
+  def save(self):
+    fname = self.getFilename()
+    if not fname:
+      raise ValueError("No filename specified for saving chunk.")
+    try:
+      with open(fname, 'w') as f:
+        json.dump(self.current, f, indent=2)
+      self.original = json.loads(json.dumps(self.current))  # Deep copy
+    except Exception as e:
+      raise RuntimeError(f"Failed to save chunk file: {e}")
+
+  def new(self):
+    self.current = {}
+    self.original = {}
+    self.onChunkData.invoke(self.current)
+
+  def isDirty(self):
+    return json.dumps(self.current, sort_keys=True) != json.dumps(self.original, sort_keys=True)
+
+  def getFilename(self):
+    if not self.mapData or not hasattr(self.mapData, 'getMapDirectory'):
+      return None
+    dir_path = self.mapData.getMapDirectory()
+    if dir_path is None:
+      return None
+    return f"{dir_path}/{self.x}_{self.y}_{self.z}.json"