feat: add InputTypesMap and _instantiate_input function (#2955)

* refactor: add _input_type attribute to dump in BaseInputMixin

* feat: add InputTypesMap and _instantiate_input function

The commit adds the `InputTypesMap` dictionary and `_instantiate_input` function to the `inputs.py` file. The `InputTypesMap` is a dictionary that maps input types to their corresponding classes, and the `_instantiate_input` function is used to instantiate an input object based on its type. This change improves the flexibility and extensibility of the codebase.

src/backend/base/langflow/inputs/input_mixin.py

@@ -87,6 +87,7 @@ class BaseInputMixin(BaseModel, validate_assignment=True):
         dump = handler(self)
         if "field_type" in dump:
             dump["type"] = dump.pop("field_type")
+        dump["_input_type"] = self.__class__.__name__
         return dump
 
 

src/backend/base/langflow/inputs/inputs.py

@@ -1,4 +1,4 @@
-from typing import Any, AsyncIterator, Iterator, Optional, Union
+from typing import Any, AsyncIterator, Iterator, Optional, Union, get_args
 
 from loguru import logger
 from pydantic import Field, field_validator
@@ -360,3 +360,13 @@ InputTypes = Union[
     MessageInput,
     TableInput,
 ]
+
+InputTypesMap: dict[str, type[InputTypes]] = {t.__name__: t for t in get_args(InputTypes)}
+
+
+def _instantiate_input(input_type: str, data: dict) -> InputTypes:
+    input_type_class = InputTypesMap.get(input_type)
+    if input_type_class:
+        return input_type_class(**data)
+    else:
+        raise ValueError(f"Invalid input type: {input_type}")