🔨 refactor(custom.py): remove unused code

✨ feat(frontend_node): add extra fields to MemoryFrontendNode and ChainFrontendNode
The unused code in custom.py has been removed. The MemoryFrontendNode and ChainFrontendNode classes have been updated to include additional fields that are required for their respective templates. The MemoryFrontendNode now has a return_messages field, and the ChainFrontendNode now has a memory field. These fields are optional and can be toggled on or off as required.

src/backend/langflow/interface/prompts/custom.py

@@ -71,7 +71,3 @@ Human: {input}
 CUSTOM_PROMPTS: Dict[str, Type[BaseCustomPrompt]] = {
     "SeriesCharacterPrompt": SeriesCharacterPrompt
 }
-
-if __name__ == "__main__":
-    prompt = SeriesCharacterPrompt(character="Harry Potter", series="Harry Potter")
-    print(prompt.template)

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

@@ -27,6 +27,9 @@ class FrontendNode(BaseModel):
     def add_extra_fields(self) -> None:
         pass
 
+    def add_extra_base_classes(self) -> None:
+        pass
+
     @staticmethod
     def format_field(field: TemplateField, name: Optional[str] = None) -> None:
         """Formats a given field based on its attributes and value."""

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

@@ -2,10 +2,24 @@ from typing import Optional
 
 from langflow.template.field.base import TemplateField
 from langflow.template.frontend_node.base import FrontendNode
+from langflow.template.frontend_node.constants import QA_CHAIN_TYPES
 from langflow.template.template.base import Template
 
 
 class ChainFrontendNode(FrontendNode):
+    def add_extra_fields(self) -> None:
+        if self.template.type_name == "ConversationalRetrievalChain":
+            # add memory
+            self.template.add_field(
+                TemplateField(
+                    field_type="BaseChatMemory",
+                    required=False,
+                    show=True,
+                    name="memory",
+                    advanced=False,
+                )
+            )
+
     @staticmethod
     def format_field(field: TemplateField, name: Optional[str] = None) -> None:
         FrontendNode.format_field(field, name)
@@ -155,3 +169,41 @@ class MidJourneyPromptChainNode(FrontendNode):
         "ConversationChain",
         "MidJourneyPromptChain",
     ]
+
+
+class CombineDocsChainNode(FrontendNode):
+    name: str = "CombineDocsChain"
+    template: Template = Template(
+        type_name="load_qa_chain",
+        fields=[
+            TemplateField(
+                field_type="str",
+                required=True,
+                is_list=True,
+                show=True,
+                multiline=False,
+                options=QA_CHAIN_TYPES,
+                value=QA_CHAIN_TYPES[0],
+                name="chain_type",
+                advanced=False,
+            ),
+            TemplateField(
+                field_type="BaseLanguageModel",
+                required=True,
+                show=True,
+                name="llm",
+                display_name="LLM",
+                advanced=False,
+            ),
+        ],
+    )
+    description: str = """Construct a zero shot agent from an LLM and tools."""
+    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:
+        # do nothing and don't return anything
+        pass

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

@@ -5,6 +5,20 @@ from langflow.template.frontend_node.base import FrontendNode
 
 
 class MemoryFrontendNode(FrontendNode):
+    #! Needs testing
+    def add_extra_fields(self) -> None:
+        # add return_messages field
+        self.template.add_field(
+            TemplateField(
+                field_type="bool",
+                required=False,
+                show=True,
+                name="return_messages",
+                advanced=False,
+                value=False,
+            )
+        )
+
     @staticmethod
     def format_field(field: TemplateField, name: Optional[str] = None) -> None:
         FrontendNode.format_field(field, name)
@@ -18,3 +32,7 @@ class MemoryFrontendNode(FrontendNode):
             field.value = 10
             field.display_name = "Memory Size"
         field.password = False
+        if field.name == "return_messages":
+            field.required = False
+            field.show = True
+            field.advanced = False