From 894fd16e8ed99b3b0aba621ae13cec06ed83cb88 Mon Sep 17 00:00:00 2001
From: Gabriel Luiz Freitas Almeida <gabriel@logspace.ai>
Date: Thu, 29 Jun 2023 09:56:59 -0300
Subject: [PATCH] =?UTF-8?q?=E2=9C=A8=20feat(retrievers):=20add=20base=20re?=
 =?UTF-8?q?triever=20class=20and=20frontend=20node=20class=20=F0=9F=90=9B?=
 =?UTF-8?q?=20fix(util.py):=20handle=20non-string=20types=20in=20format=5F?=
 =?UTF-8?q?dict=20function=20The=20base=20retriever=20class=20is=20added?=
 =?UTF-8?q?=20to=20provide=20a=20common=20interface=20for=20all=20retrieve?=
 =?UTF-8?q?rs=20in=20the=20language=20chain.=20The=20frontend=20node=20cla?=
 =?UTF-8?q?ss=20for=20retrievers=20is=20also=20added=20to=20handle=20the?=
 =?UTF-8?q?=20formatting=20of=20fields=20specific=20to=20retrievers.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

In the util.py file, a fix is made to handle non-string types in the format_dict function. Previously, if the type of a field was not a string, an error would occur. This fix ensures that the type is converted to a string before further processing.
---
 .../langflow/interface/retrievers/base.py     | 49 +++++++++++++++++++
 .../template/frontend_node/retrievers.py      | 15 ++++++
 src/backend/langflow/utils/util.py            |  3 ++
 3 files changed, 67 insertions(+)
 create mode 100644 src/backend/langflow/interface/retrievers/base.py
 create mode 100644 src/backend/langflow/template/frontend_node/retrievers.py

diff --git a/src/backend/langflow/interface/retrievers/base.py b/src/backend/langflow/interface/retrievers/base.py
new file mode 100644
index 000000000..3eb38861e
--- /dev/null
+++ b/src/backend/langflow/interface/retrievers/base.py
@@ -0,0 +1,49 @@
+from typing import Any, Dict, List, Optional, Type
+
+from langchain import retrievers
+
+from langflow.interface.base import LangChainTypeCreator
+from langflow.interface.importing.utils import import_class
+from langflow.settings import settings
+from langflow.template.frontend_node.retrievers import RetrieverFrontendNode
+from langflow.utils.logger import logger
+from langflow.utils.util import build_template_from_method
+
+
+class RetrieverCreator(LangChainTypeCreator):
+    type_name: str = "retrievers"
+
+    @property
+    def frontend_node_class(self) -> Type[RetrieverFrontendNode]:
+        return RetrieverFrontendNode
+
+    @property
+    def type_to_loader_dict(self) -> Dict:
+        if self.type_dict is None:
+            self.type_dict: dict[str, Any] = {
+                retriever_name: import_class(f"langchain.retrievers.{retriever_name}")
+                for retriever_name in retrievers.__all__
+            }
+        return self.type_dict
+
+    def get_signature(self, name: str) -> Optional[Dict]:
+        """Get the signature of an embedding."""
+        try:
+            return build_template_from_method(
+                name, type_to_cls_dict=self.type_to_loader_dict, method_name="from_llm"
+            )
+        except ValueError as exc:
+            raise ValueError(f"Retriever {name} not found") from exc
+        except AttributeError as exc:
+            logger.error(f"Retriever {name} not loaded: {exc}")
+            return None
+
+    def to_list(self) -> List[str]:
+        return [
+            retriever
+            for retriever in self.type_to_loader_dict.keys()
+            if retriever in settings.retrievers or settings.dev
+        ]
+
+
+retriever_creator = RetrieverCreator()
diff --git a/src/backend/langflow/template/frontend_node/retrievers.py b/src/backend/langflow/template/frontend_node/retrievers.py
new file mode 100644
index 000000000..b482c8b84
--- /dev/null
+++ b/src/backend/langflow/template/frontend_node/retrievers.py
@@ -0,0 +1,15 @@
+from typing import Optional
+
+from langflow.template.field.base import TemplateField
+from langflow.template.frontend_node.base import FrontendNode
+
+
+class RetrieverFrontendNode(FrontendNode):
+    @staticmethod
+    def format_field(field: TemplateField, name: Optional[str] = None) -> None:
+        FrontendNode.format_field(field, name)
+        # Define common field attributes
+        field.show = True
+        if field.name == "parser_key":
+            field.display_name = "Parser Key"
+            field.password = False
diff --git a/src/backend/langflow/utils/util.py b/src/backend/langflow/utils/util.py
index 7fcf1f4d4..02a9520b4 100644
--- a/src/backend/langflow/utils/util.py
+++ b/src/backend/langflow/utils/util.py
@@ -233,6 +233,9 @@ def format_dict(d, name: Optional[str] = None):
 
         _type = value["type"]
 
+        if not isinstance(_type, str):
+            _type = _type.__name__
+
         # Remove 'Optional' wrapper
         if "Optional" in _type:
             _type = _type.replace("Optional[", "")[:-1]