refactor(validate.py): add error handling and logging to post_validate_node function

feat(graph/base.py): add _built_object_repr method to Node class
feat(graph/nodes.py): add _built_object_repr method to DocumentLoaderNode, VectorStoreNode, and TextSplitterNode classes

src/backend/langflow/api/validate.py

@@ -9,6 +9,7 @@ from langflow.api.base import (
     PromptValidationResponse,
     validate_prompt,
 )
+from langflow.graph.nodes import VectorStoreNode
 from langflow.interface.run import build_graph
 from langflow.utils.logger import logger
 from langflow.utils.validate import validate_code
@@ -46,10 +47,11 @@ def post_validate_node(node_id: str, data: dict):
         graph = build_graph(data)
         # validate node
         node = graph.get_node(node_id)
-        if node is not None:
-            _ = node.build()
-            return json.dumps({"valid": True, "params": str(node.params)})
-        else:
-            return json.dumps({"valid": False})
+        if node is None:
+            raise ValueError(f"Node {node_id} not found")
+        if not isinstance(node, VectorStoreNode):
+            node.build()
+        return json.dumps({"valid": True, "params": str(node._built_object_repr())})
     except Exception as e:
-        logger.error(e)
+        logger.exception(e)
+        return json.dumps({"valid": False})

src/backend/langflow/graph/base.py

@@ -232,6 +232,9 @@ class Node:
     def __hash__(self) -> int:
         return id(self)
 
+    def _built_object_repr(self):
+        return repr(self._built_object)
+
 
 class Edge:
     def __init__(self, source: "Node", target: "Node"):

src/backend/langflow/graph/nodes.py

@@ -139,6 +139,13 @@ class DocumentLoaderNode(Node):
     def __init__(self, data: Dict):
         super().__init__(data, base_type="documentloaders")
 
+    def _built_object_repr(self):
+        # This built_object is a list of documents. Maybe we should
+        # show how many documents are in the list?
+        if self._built_object:
+            return f"""{self.node_type}({len(self._built_object)} documents)\nDocuments: {self._built_object[:3]}..."""
+        return f"{self.node_type}()"
+
 
 class EmbeddingNode(Node):
     def __init__(self, data: Dict):
@@ -149,6 +156,9 @@ class VectorStoreNode(Node):
     def __init__(self, data: Dict):
         super().__init__(data, base_type="vectorstores")
 
+    def _built_object_repr(self):
+        return "Vector stores can take time to build. It will build on the first query."
+
 
 class MemoryNode(Node):
     def __init__(self, data: Dict):
@@ -158,3 +168,10 @@ class MemoryNode(Node):
 class TextSplitterNode(Node):
     def __init__(self, data: Dict):
         super().__init__(data, base_type="textsplitters")
+
+    def _built_object_repr(self):
+        # This built_object is a list of documents. Maybe we should
+        # show how many documents are in the list?
+        if self._built_object:
+            return f"""{self.node_type}({len(self._built_object)} documents)\nDocuments: {self._built_object[:3]}..."""
+        return f"{self.node_type}()"