feat(langflow): add support for async functions in Node's func parameter

fix(langflow): fix Node's func parameter to be a coroutine function if it is a sync function

src/backend/langflow/__init__.py

@@ -1 +1,4 @@
-from langflow.interface.loading import load_flow_from_json  # noqa
+from langflow.interface.loading import load_flow_from_json
+from langflow.cache import cache_manager
+
+__all__ = ["load_flow_from_json", "cache_manager"]

src/backend/langflow/graph/base.py

@@ -4,6 +4,7 @@
 #   - Build each inner agent first, then build the outer agent
 
 import contextlib
+import inspect
 import types
 import warnings
 from copy import deepcopy
@@ -14,6 +15,7 @@ from langflow.graph.constants import DIRECT_TYPES
 from langflow.interface import loading
 from langflow.interface.listing import ALL_TYPES_DICT
 from langflow.utils.logger import logger
+from langflow.utils.util import sync_to_async
 
 
 class Node:
@@ -158,13 +160,20 @@ class Node:
                     continue
                 result = value.build()
                 # If the key is "func", then we need to use the run method
-                if key == "func" and not isinstance(result, types.FunctionType):
+                if key == "func":
+                    if not isinstance(result, types.FunctionType):
                         # func can be PythonFunction(code='\ndef upper_case(text: str) -> str:\n    return text.upper()\n')
                         # so we need to check if there is an attribute called run
                         if hasattr(result, "run"):
                             result = result.run  # type: ignore
                         elif hasattr(result, "get_function"):
                             result = result.get_function()  # type: ignore
+                    elif inspect.iscoroutinefunction(result):
+                        self.params["coroutine"] = result
+                    else:
+                        # turn result which is a function into a coroutine
+                        # so that it can be awaited
+                        self.params["coroutine"] = sync_to_async(result)
 
                 self.params[key] = result
             elif isinstance(value, list) and all(

src/backend/langflow/utils/util.py

@@ -1,3 +1,5 @@
+import asyncio
+from functools import partial, wraps
 import importlib
 import inspect
 import re
@@ -301,3 +303,17 @@ def update_verbose(d: dict, new_value: bool) -> dict:
         elif k == "verbose":
             d[k] = new_value
     return d
+
+
+def sync_to_async(func):
+    """
+    Decorator to convert a sync function to an async function.
+    """
+
+    @wraps(func)
+    async def async_wrapper(*args, **kwargs):
+        loop = asyncio.get_event_loop()
+        func_call = partial(func, *args, **kwargs)
+        return await loop.run_in_executor(None, func_call)
+
+    return async_wrapper

src/backend/langflow/utils/validate.py

@@ -155,7 +155,7 @@ def create_function(code, function_name):
     exec_globals[function_name] = locals()[function_name]
 
     # Return a function that imports necessary modules and calls the target function
-    def wrapped_function(*args, **kwargs):
+    async def wrapped_function(*args, **kwargs):
         for module_name, module in exec_globals.items():
             if isinstance(module, type(importlib)):
                 globals()[module_name] = module