Fix: Correct file variable handling for custom tools in workflow

api/core/workflow/nodes/tool/tool_node.py

@@ -279,6 +279,37 @@ class ToolNode(BaseNode[ToolNodeData]):
                 json.append(message.message.json_object)
             elif message.type == ToolInvokeMessage.MessageType.LINK:
                 assert isinstance(message.message, ToolInvokeMessage.TextMessage)
+                url = message.message.text
+
+                # 获取 transfer_method，与其他类型保持一致
+                if message.meta:
+                    transfer_method = message.meta.get("transfer_method", FileTransferMethod.TOOL_FILE)
+                else:
+                    transfer_method = FileTransferMethod.TOOL_FILE
+
+                tool_file_id = str(url).rsplit('/', maxsplit=1)[-1].split(".")[0]
+
+                with Session(db.engine) as session:
+                    stmt = select(ToolFile).where(ToolFile.id == tool_file_id)
+                    tool_file = session.scalar(stmt)
+                    if tool_file is None:
+                        raise ToolFileError(f"Tool file {tool_file_id} does not exist")
+
+                # 完整的 mapping 信息
+                mapping = {
+                    "tool_file_id": tool_file_id,
+                    "type": file_factory.get_file_type_by_mime_type(tool_file.mimetype),
+                    "transfer_method": transfer_method,
+                    "url": url,
+                }
+
+                file = file_factory.build_from_mapping(
+                    mapping=mapping,
+                    tenant_id=self.tenant_id,
+                )
+                files.append(file)
+
+                # 保持原有的文本处理
                 stream_text = f"Link: {message.message.text}\n"
                 text += stream_text
                 yield RunStreamChunkEvent(chunk_content=stream_text, from_variable_selector=[self.node_id, "text"])