refact: more maintable build_nodes (#123)

src/backend/langflow/api/base.py

@@ -1,6 +1,7 @@
-from langflow.graph.utils import extract_input_variables_from_prompt
 from pydantic import BaseModel, validator
 
+from langflow.graph.utils import extract_input_variables_from_prompt
+
 
 class Code(BaseModel):
     code: str

src/backend/langflow/config.yaml

@@ -29,10 +29,10 @@ llms:
   - HuggingFaceHub
 
 tools:
-  # - Search
+  - Search
   - PAL-MATH
   - Calculator
-  # - Serper Search
+  - Serper Search
   - Tool
   - PythonFunction
   - JsonSpec

src/backend/langflow/graph/graph.py

@@ -1,4 +1,4 @@
-from typing import Dict, List, Union
+from typing import Dict, List, Type, Union
 
 from langflow.graph.base import Edge, Node
 from langflow.graph.nodes import (
@@ -15,13 +15,12 @@ from langflow.graph.nodes import (
 from langflow.interface.agents.base import agent_creator
 from langflow.interface.chains.base import chain_creator
 from langflow.interface.llms.base import llm_creator
+from langflow.interface.memories.base import memory_creator
 from langflow.interface.prompts.base import prompt_creator
 from langflow.interface.toolkits.base import toolkits_creator
 from langflow.interface.tools.base import tool_creator
 from langflow.interface.tools.constants import FILE_TOOLS
-from langflow.interface.tools.util import get_tools_dict
 from langflow.interface.wrappers.base import wrapper_creator
-from langflow.interface.memories.base import memory_creator
 from langflow.utils import payload
 
 
@@ -108,6 +107,26 @@ class Graph:
             edges.append(Edge(source, target))
         return edges
 
+    def _get_node_class(self, node_type: str, node_lc_type: str) -> Type[Node]:
+        node_type_map: Dict[str, Type[Node]] = {
+            **{t: PromptNode for t in prompt_creator.to_list()},
+            **{t: AgentNode for t in agent_creator.to_list()},
+            **{t: ChainNode for t in chain_creator.to_list()},
+            **{t: ToolNode for t in tool_creator.to_list()},
+            **{t: ToolkitNode for t in toolkits_creator.to_list()},
+            **{t: WrapperNode for t in wrapper_creator.to_list()},
+            **{t: LLMNode for t in llm_creator.to_list()},
+            **{t: MemoryNode for t in memory_creator.to_list()},
+        }
+
+        if node_type in FILE_TOOLS:
+            return FileToolNode
+        if node_type in node_type_map:
+            return node_type_map[node_type]
+        if node_lc_type in node_type_map:
+            return node_type_map[node_lc_type]
+        return Node
+
     def _build_nodes(self) -> List[Node]:
         nodes: List[Node] = []
         for node in self._nodes:
@@ -115,38 +134,9 @@ class Graph:
             node_type: str = node_data["type"]  # type: ignore
             node_lc_type: str = node_data["node"]["template"]["_type"]  # type: ignore
 
-            if node_type in prompt_creator.to_list():
+            NodeClass = self._get_node_class(node_type, node_lc_type)
-                nodes.append(PromptNode(node))
+            nodes.append(NodeClass(node))
-            elif (
+
-                node_type in agent_creator.to_list()
-                or node_lc_type in agent_creator.to_list()
-            ):
-                nodes.append(AgentNode(node))
-            elif node_type in chain_creator.to_list():
-                nodes.append(ChainNode(node))
-            elif (
-                node_type in tool_creator.to_list()
-                or node_lc_type in get_tools_dict().keys()
-            ):
-                if node_type in FILE_TOOLS:
-                    nodes.append(FileToolNode(node))
-                nodes.append(ToolNode(node))
-            elif node_type in toolkits_creator.to_list():
-                nodes.append(ToolkitNode(node))
-            elif node_type in wrapper_creator.to_list():
-                nodes.append(WrapperNode(node))
-            elif (
-                node_type in llm_creator.to_list()
-                or node_lc_type in llm_creator.to_list()
-            ):
-                nodes.append(LLMNode(node))
-            elif (
-                node_type in memory_creator.to_list()
-                or node_lc_type in memory_creator.to_list()
-            ):
-                nodes.append(MemoryNode(node))
-            else:
-                nodes.append(Node(node))
         return nodes
 
     def get_children_by_node_type(self, node: Node, node_type: str) -> List[Node]:

tests/test_prompts_template.py

@@ -167,7 +167,7 @@ def test_zero_shot_prompt(client: TestClient):
         "placeholder": "",
         "show": True,
         "multiline": True,
-        "value": "Answer the following questions as best you can. You have access to the following tools:", # noqa: E501
+        "value": "Answer the following questions as best you can. You have access to the following tools:",  # noqa: E501
         "password": False,
         "name": "prefix",
         "type": "str",
@@ -189,7 +189,7 @@ def test_zero_shot_prompt(client: TestClient):
         "placeholder": "",
         "show": False,
         "multiline": False,
-        "value": "Use the following format:\n\nQuestion: the input question you must answer\nThought: you should always think about what to do\nAction: the action to take, should be one of [{tool_names}]\nAction Input: the input to the action\nObservation: the result of the action\n... (this Thought/Action/Action Input/Observation can repeat N times)\nThought: I now know the final answer\nFinal Answer: the final answer to the original input question", # noqa: E501
+        "value": "Use the following format:\n\nQuestion: the input question you must answer\nThought: you should always think about what to do\nAction: the action to take, should be one of [{tool_names}]\nAction Input: the input to the action\nObservation: the result of the action\n... (this Thought/Action/Action Input/Observation can repeat N times)\nThought: I now know the final answer\nFinal Answer: the final answer to the original input question",  # noqa: E501
         "password": False,
         "name": "format_instructions",
         "type": "str",