Added Controls testing + documentation

src/myfasthtml/core/instances.py

@@ -84,7 +84,7 @@ class BaseInstance:
     return self._prefix
   
   def get_full_id(self) -> str:
-    return f"{InstancesManager.get_session_id(self._session)}-{self._id}"
+    return f"{InstancesManager.get_session_id(self._session)}#{self._id}"
   
   def get_full_parent_id(self) -> Optional[str]:
     parent = self.get_parent()
@@ -176,11 +176,22 @@ class InstancesManager:
     :param instance_id:
     :return:
     """
-    key = (InstancesManager.get_session_id(session), instance_id)
+    session_id = InstancesManager.get_session_id(session)
+    key = (session_id, instance_id)
     return InstancesManager.instances[key]
   
+  @staticmethod
+  def get_by_type(session: dict, cls: type):
+    session_id = InstancesManager.get_session_id(session)
+    res = [i for s, i in InstancesManager.instances.items() if s[0] == session_id and isinstance(i, cls)]
+    assert len(res) <= 1, f"Multiple instances of type {cls.__name__} found"
+    assert len(res) > 0, f"No instance of type {cls.__name__} found"
+    return res[0]
+  
   @staticmethod
   def get_session_id(session):
+    if isinstance(session, str):
+      return session
     if session is None:
       return "** NOT LOGGED IN **"
     if "user_info" not in session: