Added Layout and UserProfile

src/myfasthtml/core/instances.py

@@ -0,0 +1,89 @@
+import uuid
+
+
+class DuplicateInstanceError(Exception):
+  def __init__(self, instance):
+    self.instance = instance
+
+
+class BaseInstance:
+  """
+  Base class for all instances (manageable by InstancesManager)
+  """
+  
+  def __init__(self, session: dict, _id: str):
+    self._session = session
+    self._id = _id
+    InstancesManager.register(session, self)
+  
+  def get_id(self):
+    return self._id
+  
+  def get_session(self):
+    return self._session
+
+
+class SingleInstance(BaseInstance):
+  """
+  Base class for instances that can only have one instance at a time.
+  """
+  
+  def __init__(self, session: dict, prefix: str):
+    super().__init__(session, prefix)
+    self._instance = None
+
+
+class MultipleInstance(BaseInstance):
+  """
+  Base class for instances that can have multiple instances at a time.
+  """
+  
+  def __init__(self, session: dict, prefix: str):
+    super().__init__(session, f"{prefix}-{str(uuid.uuid4())}")
+    self._instance = None
+
+
+class InstancesManager:
+  instances = {}
+  
+  @staticmethod
+  def register(session: dict, instance: BaseInstance):
+    """
+    Register an instance in the manager, so that it can be retrieved later.
+    :param session:
+    :param instance:
+    :return:
+    """
+    key = (InstancesManager._get_session_id(session), instance.get_id())
+    
+    if isinstance(instance, SingleInstance) and key in InstancesManager.instances:
+      raise DuplicateInstanceError(instance)
+    
+    InstancesManager.instances[key] = instance
+    return instance
+  
+  @staticmethod
+  def get(session: dict, instance_id: str, instance_type: type = None, *args, **kwargs):
+    """
+    Get or create an instance of the given type (from its id)
+    :param session:
+    :param instance_id:
+    :param instance_type:
+    :param args:
+    :param kwargs:
+    :return:
+    """
+    try:
+      key = (InstancesManager._get_session_id(session), instance_id)
+      
+      return InstancesManager.instances[key]
+    except KeyError:
+      return instance_type(session, *args, **kwargs)  # it will be automatically registered
+  
+  @staticmethod
+  def _get_session_id(session):
+    if not session:
+      return "** NOT LOGGED IN **"
+    if "user_info" not in session:
+      return "** UNKNOWN USER **"
+    return session["user_info"].get("id", "** INVALID SESSION **")