from __future__ import annotations from typing import Optional, Type from langchain_core.callbacks import ( AsyncCallbackManagerForToolRun, CallbackManagerForToolRun, ) from langchain_core.pydantic_v1 import BaseModel from langchain_community.tools.playwright.base import BaseBrowserTool from langchain_community.tools.playwright.utils import ( aget_current_page, get_current_page, ) class NavigateBackTool(BaseBrowserTool): """Navigate back to the previous page in the browser history.""" name: str = "previous_webpage" description: str = "Navigate back to the previous page in the browser history" args_schema: Type[BaseModel] = BaseModel def _run(self, run_manager: Optional[CallbackManagerForToolRun] = None) -> str: """Use the tool.""" if self.sync_browser is None: raise ValueError(f"Synchronous browser not provided to {self.name}") page = get_current_page(self.sync_browser) response = page.go_back() if response: return ( f"Navigated back to the previous page with URL '{response.url}'." f" Status code {response.status}" ) else: return "Unable to navigate back; no previous page in the history" async def _arun( self, run_manager: Optional[AsyncCallbackManagerForToolRun] = None, ) -> str: """Use the tool.""" if self.async_browser is None: raise ValueError(f"Asynchronous browser not provided to {self.name}") page = await aget_current_page(self.async_browser) response = await page.go_back() if response: return ( f"Navigated back to the previous page with URL '{response.url}'." f" Status code {response.status}" ) else: return "Unable to navigate back; no previous page in the history"