fix: check if variable is valid before converting (#3514)

* feat: Add logging and session imports to endpoints.py

Import logging and session modules for better error handling and database interaction in endpoints.py.

* refactor: Improve custom component parameter handling in update endpoint

* feat: Add parse_value function to parse values based on input type

Add a new function `parse_value` to `utils.py` that parses values based on the input type provided. The function handles different input types such as 'IntInput' and 'FloatInput' to ensure proper parsing.

* feat: Refactor custom_component_update() to use parse_value utility function

Use parse_value utility function to handle different input types and empty values in custom_component_update() for better readability and maintainability.

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

@@ -1,6 +1,6 @@
 import uuid
 import warnings
-from typing import TYPE_CHECKING, Optional, Dict
+from typing import TYPE_CHECKING, Any, Optional, Dict
 
 from fastapi import HTTPException
 from sqlmodel import Session
@@ -227,3 +227,15 @@ def get_suggestion_message(outdated_components: list[str]) -> str:
     else:
         components = ", ".join(outdated_components)
         return f"The flow contains {count} outdated components. We recommend updating the following components: {components}."
+
+
+def parse_value(value: Any, input_type: str) -> Any:
+    """Helper function to parse the value based on input type."""
+    if value == "":
+        return value
+    elif input_type == "IntInput":
+        return int(value) if value is not None else None
+    elif input_type == "FloatInput":
+        return float(value) if value is not None else None
+    else:
+        return value

src/backend/base/langflow/api/v1/endpoints.py

@@ -6,6 +6,10 @@
 
 import sqlalchemy as sa
 from fastapi import APIRouter, BackgroundTasks, Body, Depends, HTTPException, Request, UploadFile, status
+from loguru import logger
+from sqlmodel import Session, select
+
+from langflow.api.utils import parse_value
 from langflow.api.v1.schemas import (
     ConfigResponse,
     CustomComponentRequest,
@@ -45,8 +49,6 @@
 from langflow.services.telemetry.schema import RunPayload
 from langflow.services.telemetry.service import TelemetryService
 from langflow.utils.version import get_version_info
-from loguru import logger
-from sqlmodel import Session, select
 
 if TYPE_CHECKING:
     from langflow.services.cache.base import CacheService
@@ -590,17 +592,14 @@ async def custom_component_update(
         )
         if hasattr(cc_instance, "set_attributes"):
             template = code_request.get_template()
-            params = {
-                key: value_dict.get("value")
-                if value_dict.get("_input_type") != "IntInput"
-                else (
-                    int(value_dict.get("value"))  # type: ignore
-                    if value_dict.get("_input_type") != "FloatInput"
-                    else float(value_dict.get("value"))  # type: ignore
-                )
-                for key, value_dict in template.items()
-                if isinstance(value_dict, dict)
-            }
+            params = {}
+
+            for key, value_dict in template.items():
+                if isinstance(value_dict, dict):
+                    value = value_dict.get("value")
+                    input_type = str(value_dict.get("_input_type"))
+                    params[key] = parse_value(value, input_type)
+
             load_from_db_fields = [
                 field_name
                 for field_name, field_dict in template.items()