🔧 fix(manager.py): import List from typing module to fix type hinting error

✨ feat(manager.py): add support for registering factories with dependencies to handle service creation
🔧 fix(manager.py): fix service creation logic to handle dependencies and create services in the correct order
✨ feat(manager.py): add support for initializing session manager with dependencies

src/backend/langflow/services/manager.py

@@ -1,5 +1,5 @@
 from langflow.services.schema import ServiceType
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, List
 
 if TYPE_CHECKING:
     from langflow.services.factory import ServiceFactory
@@ -13,13 +13,19 @@ class ServiceManager:
     def __init__(self):
         self.services = {}
         self.factories = {}
+        self.dependencies = {}
 
-    def register_factory(self, service_factory: "ServiceFactory"):
+    def register_factory(
+        self, service_factory: "ServiceFactory", dependencies: List[ServiceType] = None
+    ):
         """
-        Registers a new factory.
+        Registers a new factory with dependencies.
         """
-        if service_factory.service_class.name not in self.factories:
-            self.factories[service_factory.service_class.name] = service_factory
+        if dependencies is None:
+            dependencies = []
+        service_name = service_factory.service_class.name
+        self.factories[service_name] = service_factory
+        self.dependencies[service_name] = dependencies
 
     def get(self, service_name: ServiceType):
         """
@@ -32,17 +38,25 @@ class ServiceManager:
 
     def _create_service(self, service_name: ServiceType):
         """
-        Create a new service given its name.
+        Create a new service given its name, handling dependencies.
         """
         self._validate_service_creation(service_name)
 
-        if service_name == ServiceType.SETTINGS_MANAGER:
-            self.services[service_name] = self.factories[service_name].create()
-        else:
-            settings_service = self.get(ServiceType.SETTINGS_MANAGER)
-            self.services[service_name] = self.factories[service_name].create(
-                settings_service
-            )
+        # Create dependencies first
+        for dependency in self.dependencies.get(service_name, []):
+            if dependency not in self.services:
+                self._create_service(dependency)
+
+        # Collect the dependent services
+        dependent_services = {
+            dep.value: self.services[dep]
+            for dep in self.dependencies.get(service_name, [])
+        }
+
+        # Create the actual service
+        self.services[service_name] = self.factories[service_name].create(
+            **dependent_services
+        )
 
     def _validate_service_creation(self, service_name: ServiceType):
         """
@@ -53,14 +67,6 @@ class ServiceManager:
                 f"No factory registered for the service class '{service_name.name}'"
             )
 
-        if (
-            ServiceType.SETTINGS_MANAGER not in self.factories
-            and service_name != ServiceType.SETTINGS_MANAGER
-        ):
-            raise ValueError(
-                f"Cannot create service '{service_name.name}' before the settings service"
-            )
-
     def update(self, service_name: ServiceType):
         """
         Update a service by its name.
@@ -81,11 +87,26 @@ def initialize_services():
     from langflow.services.cache import factory as cache_factory
     from langflow.services.chat import factory as chat_factory
     from langflow.services.settings import factory as settings_factory
+    from langflow.services.session import factory as session_manager_factory
 
     service_manager.register_factory(settings_factory.SettingsManagerFactory())
-    service_manager.register_factory(database_factory.DatabaseManagerFactory())
-    service_manager.register_factory(cache_factory.CacheManagerFactory())
+    service_manager.register_factory(
+        database_factory.DatabaseManagerFactory(),
+        dependencies=[ServiceType.SETTINGS_MANAGER],
+    )
+    service_manager.register_factory(
+        cache_factory.CacheManagerFactory(), dependencies=[ServiceType.SETTINGS_MANAGER]
+    )
     service_manager.register_factory(chat_factory.ChatManagerFactory())
+    service_manager.register_factory(
+        session_manager_factory.SessionManagerFactory(),
+        dependencies=[ServiceType.CACHE_MANAGER],
+    )
+
+    # Test cache connection
+    service_manager.get(ServiceType.CACHE_MANAGER)
+    # Test database connection
+    service_manager.get(ServiceType.DATABASE_MANAGER)
 
 
 def initialize_settings_manager():
@@ -95,3 +116,22 @@ def initialize_settings_manager():
     from langflow.services.settings import factory as settings_factory
 
     service_manager.register_factory(settings_factory.SettingsManagerFactory())
+
+
+def initialize_session_manager():
+    """
+    Initialize the session manager.
+    """
+    from langflow.services.session import factory as session_manager_factory
+    from langflow.services.cache import factory as cache_factory
+
+    initialize_settings_manager()
+
+    service_manager.register_factory(
+        cache_factory.CacheManagerFactory(), dependencies=[ServiceType.SETTINGS_MANAGER]
+    )
+
+    service_manager.register_factory(
+        session_manager_factory.SessionManagerFactory(),
+        dependencies=[ServiceType.CACHE_MANAGER],
+    )