Fixed memory leak for instances

src/myfasthtml/core/instances.py

@@ -31,9 +31,8 @@ class BaseInstance:
     session = args[1] if len(args) > 1 and isinstance(args[1], dict) else kwargs.get("session", None)
     _id = args[2] if len(args) > 2 and isinstance(args[2], str) else kwargs.get("_id", None)
     
-    # Compute _id if not provided
-    if _id is None:
-      _id = cls.compute_id()
+    # Compute _id
+    _id = cls.compute_id(_id, parent)
     
     if session is None:
       if parent is not None:
@@ -68,7 +67,7 @@ class BaseInstance:
     
     self._parent = parent
     self._session = session or (parent.get_session() if parent else None)
-    self._id = _id or self.compute_id()
+    self._id = self.compute_id(_id, parent)
     self._prefix = self._id if isinstance(self, (UniqueInstance, SingleInstance)) else self.compute_prefix()
     
     if auto_register:
@@ -98,12 +97,18 @@ class BaseInstance:
     return f"mf-{pascal_to_snake(cls.__name__)}"
   
   @classmethod
-  def compute_id(cls):
-    prefix = cls.compute_prefix()
-    if issubclass(cls, SingleInstance):
-      _id = prefix
-    else:
-      _id = f"{prefix}-{str(uuid.uuid4())}"
+  def compute_id(cls, _id: Optional[str], parent: Optional['BaseInstance']):
+    if _id is None:
+      prefix = cls.compute_prefix()
+      if issubclass(cls, SingleInstance):
+        _id = prefix
+      else:
+        _id = f"{prefix}-{str(uuid.uuid4())}"
+      return _id
+    
+    if _id.startswith("-") and parent is not None:
+      return f"{parent.get_prefix()}{_id}"
+    
     return _id