Add extra base class and modify field formatting in ChainFrontendNode

src/backend/langflow/template/frontend_node/chains.py

@@ -7,6 +7,11 @@ from langflow.template.template.base import Template
 
 
 class ChainFrontendNode(FrontendNode):
+    output_type: str = "Chain"
+
+    def add_extra_base_classes(self) -> None:
+        self.base_classes.append("Text")
+
     def add_extra_fields(self) -> None:
         if self.template.type_name == "ConversationalRetrievalChain":
             # add memory
@@ -48,16 +53,16 @@ class ChainFrontendNode(FrontendNode):
     @staticmethod
     def format_field(field: TemplateField, name: Optional[str] = None) -> None:
         FrontendNode.format_field(field, name)
-        key = field.name or ""
-        if "name" == "RetrievalQA" and key == "memory":
+
+        if "name" == "RetrievalQA" and field.name == "memory":
             field.show = False
             field.required = False
 
         field.advanced = False
-        if "key" in key:
+        if "key" in field.name:
             field.password = False
             field.show = False
-        if key in ["input_key", "output_key"]:
+        if field.name in ["input_key", "output_key"]:
             field.required = True
             field.show = True
             field.advanced = True
@@ -71,26 +76,26 @@ class ChainFrontendNode(FrontendNode):
         #     field.value = field.value.template
 
         # Separated for possible future changes
-        if key == "prompt" and field.value is None:
+        if field.name == "prompt" and field.value is None:
             field.required = True
             field.show = True
             field.advanced = False
-        if key == "memory":
+        if field.name == "memory":
             # field.required = False
             field.show = True
             field.advanced = False
-        if key == "verbose":
+        if field.name == "verbose":
             field.required = False
             field.show = False
             field.advanced = True
-        if key == "llm":
+        if field.name == "llm":
             field.required = True
             field.show = True
             field.advanced = False
-            field.field_type = "BaseLanguageModel"  # temporary fix
+            field.field_type = "BaseLanguageModel"
             field.is_list = False
 
-        if key == "return_source_documents":
+        if field.name == "return_source_documents":
             field.required = False
             field.show = True
             field.advanced = True
@@ -98,6 +103,7 @@ class ChainFrontendNode(FrontendNode):
 
 
 class SeriesCharacterChainNode(FrontendNode):
+    output_type: str = "Chain"
     name: str = "SeriesCharacterChain"
     template: Template = Template(
         type_name="SeriesCharacterChain",
@@ -135,20 +141,19 @@ class SeriesCharacterChainNode(FrontendNode):
             ),
         ],
     )
-    description: str = (
-        "SeriesCharacterChain is a chain you can use to have a conversation with a character from a series."  # noqa
-    )
+    description: str = "SeriesCharacterChain is a chain you can use to have a conversation with a character from a series."  # noqa
     base_classes: list[str] = [
         "LLMChain",
         "BaseCustomChain",
         "Chain",
         "ConversationChain",
         "SeriesCharacterChain",
-        "Callable",
+        "function",
     ]
 
 
 class TimeTravelGuideChainNode(FrontendNode):
+    output_type: str = "Chain"
     name: str = "TimeTravelGuideChain"
     template: Template = Template(
         type_name="TimeTravelGuideChain",
@@ -184,6 +189,7 @@ class TimeTravelGuideChainNode(FrontendNode):
 
 
 class MidJourneyPromptChainNode(FrontendNode):
+    output_type: str = "Chain"
     name: str = "MidJourneyPromptChain"
     template: Template = Template(
         type_name="MidJourneyPromptChain",
@@ -219,6 +225,7 @@ class MidJourneyPromptChainNode(FrontendNode):
 
 
 class CombineDocsChainNode(FrontendNode):
+    output_type: str = "Chain"
     name: str = "CombineDocsChain"
     template: Template = Template(
         type_name="load_qa_chain",
@@ -245,7 +252,10 @@ class CombineDocsChainNode(FrontendNode):
         ],
     )
     description: str = """Load question answering chain."""
-    base_classes: list[str] = ["BaseCombineDocumentsChain", "Callable"]
+    base_classes: list[str] = ["BaseCombineDocumentsChain", "function"]
+
+    def to_dict(self):
+        return super().to_dict()
 
     @staticmethod
     def format_field(field: TemplateField, name: Optional[str] = None) -> None: