refactor(validate.py): extract build_graph function to langflow.interface.run module

feat(validate.py): add post_validate_node endpoint to validate a single node in the graph by its id

src/backend/langflow/api/validate.py

@@ -7,6 +7,7 @@ from langflow.api.base import (
     PromptValidationResponse,
     validate_prompt,
 )
+from langflow.interface.run import build_graph
 from langflow.utils.logger import logger
 from langflow.utils.validate import validate_code
 
@@ -33,3 +34,20 @@ def post_validate_prompt(prompt: Prompt):
     except Exception as e:
         logger.exception(e)
         raise HTTPException(status_code=500, detail=str(e)) from e
+
+
+# validate node
+@router.post("/node/{node_id}", status_code=200)
+def post_validate_node(node_id: str, data: dict):
+    try:
+        # build graph
+        graph = build_graph(data)
+        # validate node
+        node = graph.get_node(node_id)
+        if node is not None:
+            _ = node.build()
+            return node.params
+        raise
+    except Exception as e:
+        logger.exception(e)
+        raise HTTPException(status_code=500, detail=str(e)) from e

src/backend/langflow/interface/run.py

@@ -39,16 +39,16 @@ def build_langchain_object_with_caching(data_graph):
     """
 
     logger.debug("Building langchain object")
-    nodes = data_graph["nodes"]
+    graph = build_graph(data_graph)
-    # Add input variables
-    # nodes = payload.extract_input_variables(nodes)
-    # Nodes, edges and root node
-    edges = data_graph["edges"]
-    graph = Graph(nodes, edges)
-
     return graph.build()
 
 
+def build_graph(data_graph):
+    nodes = data_graph["nodes"]
+    edges = data_graph["edges"]
+    return Graph(nodes, edges)
+
+
 def build_langchain_object(data_graph):
     """
     Build langchain object from data_graph.