refactor(CustomComponent): make initialization separate from constructor (#2704)

src/backend/base/langflow/custom/custom_component/component.py

@@ -40,14 +40,16 @@ class Component(CustomComponent):
     code_class_base_inheritance: ClassVar[str] = "Component"
 
     def __init__(self, **data):
-        super().__init__(**data)
         self._inputs: dict[str, InputTypes] = {}
         self._results: dict[str, Any] = {}
         self._attributes: dict[str, Any] = {}
+        self._parameters: dict[str, Any] = {}
+        super().__init__(**data)
         if not hasattr(self, "trace_type"):
             self.trace_type = "chain"
         if self.inputs is not None:
             self.map_inputs(self.inputs)
+        self.set_attributes(self._parameters)
 
     def __getattr__(self, name: str) -> Any:
         if "_attributes" in self.__dict__ and name in self.__dict__["_attributes"]:

src/backend/base/langflow/custom/custom_component/custom_component.py

@@ -14,7 +14,7 @@ from langflow.schema.artifact import get_artifact_type
 from langflow.schema.dotdict import dotdict
 from langflow.schema.log import LoggableType
 from langflow.schema.schema import OutputLog
-from langflow.services.deps import get_storage_service, get_variable_service, session_scope
+from langflow.services.deps import get_storage_service, get_tracing_service, get_variable_service, session_scope
 from langflow.services.storage.service import StorageService
 from langflow.services.tracing.schema import Log
 from langflow.template.utils import update_frontend_node_with_template_values
@@ -88,6 +88,21 @@ class CustomComponent(BaseComponent):
     _logs: List[Log] = []
     tracing_service: Optional["TracingService"] = None
 
+    def set_attributes(self, parameters: dict):
+        pass
+
+    def set_parameters(self, parameters: dict):
+        self._parameters = parameters
+        self.set_attributes(self._parameters)
+
+    @classmethod
+    def initialize(cls, **kwargs):
+        user_id = kwargs.pop("user_id", None)
+        vertex = kwargs.pop("vertex", None)
+        tracing_service = kwargs.pop("tracing_service", get_tracing_service())
+        params_copy = kwargs.copy()
+        return cls(user_id=user_id, _parameters=params_copy, vertex=vertex, tracing_service=tracing_service)
+
     @property
     def trace_name(self):
         return f"{self.display_name} ({self.vertex.id})"

src/backend/base/langflow/interface/initialize/loading.py

@@ -57,7 +57,7 @@ async def build_component_and_get_results(
     params_copy = params.copy()
     # Remove code from params
     class_object: Type["CustomComponent" | "Component"] = eval_custom_component_code(params_copy.pop("code"))
-    custom_component: "CustomComponent" | "Component" = class_object(
+    custom_component: "CustomComponent" | "Component" = class_object.initialize(
         user_id=user_id,
         parameters=params_copy,
         vertex=vertex,
@@ -66,12 +66,13 @@ async def build_component_and_get_results(
     params_copy = update_params_with_load_from_db_fields(
         custom_component, params_copy, vertex.load_from_db_fields, fallback_to_env_vars
     )
+    custom_component.set_parameters(params_copy)
     with warnings.catch_warnings():
         warnings.filterwarnings("ignore", category=PydanticDeprecatedSince20)
         if base_type == "custom_components" and isinstance(custom_component, CustomComponent):
             return await build_custom_component(params=params_copy, custom_component=custom_component)
         elif base_type == "component" and isinstance(custom_component, Component):
-            return await build_component(params=params_copy, custom_component=custom_component)
+            return await build_component(custom_component=custom_component)
         else:
             raise ValueError(f"Base type {base_type} not found.")
 
@@ -146,11 +147,9 @@ def update_params_with_load_from_db_fields(
 
 
 async def build_component(
-    params: dict,
     custom_component: "Component",
 ):
     # Now set the params as attributes of the custom_component
-    custom_component.set_attributes(params)
     build_results, artifacts = await custom_component.build_results()
 
     return custom_component, build_results, artifacts

src/backend/base/langflow/utils/validate.py

@@ -250,17 +250,17 @@ def build_class_constructor(compiled_class, exec_globals, class_name):
     exec_globals[class_name] = locals()[class_name]
 
     # Return a function that imports necessary modules and creates an instance of the target class
-    def build_custom_class(*args, **kwargs):
+    def build_custom_class():
         for module_name, module in exec_globals.items():
             if isinstance(module, type(importlib)):
                 globals()[module_name] = module
 
-        instance = exec_globals[class_name](*args, **kwargs)
+        exec_globals[class_name]
 
-        return instance
+        return exec_globals[class_name]
 
     build_custom_class.__globals__.update(exec_globals)
-    return build_custom_class
+    return build_custom_class()
 
 
 def get_default_imports(code_string):