import contextlib import re from pathlib import Path from typing import Any, List, Optional, Tuple from urllib.parse import unquote from langchain_core.documents import Document from langchain_community.document_loaders.directory import DirectoryLoader from langchain_community.document_loaders.pdf import PyPDFLoader from langchain_community.document_loaders.web_base import WebBaseLoader class BlackboardLoader(WebBaseLoader): """Load a `Blackboard` course. This loader is not compatible with all Blackboard courses. It is only compatible with courses that use the new Blackboard interface. To use this loader, you must have the BbRouter cookie. You can get this cookie by logging into the course and then copying the value of the BbRouter cookie from the browser's developer tools. Example: .. code-block:: python from langchain_community.document_loaders import BlackboardLoader loader = BlackboardLoader( blackboard_course_url="https://blackboard.example.com/webapps/blackboard/execute/announcement?method=search&context=course_entry&course_id=_123456_1", bbrouter="expires:12345...", ) documents = loader.load() """ # noqa: E501 def __init__( self, blackboard_course_url: str, bbrouter: str, load_all_recursively: bool = True, basic_auth: Optional[Tuple[str, str]] = None, cookies: Optional[dict] = None, continue_on_failure: bool = False, ): """Initialize with blackboard course url. The BbRouter cookie is required for most blackboard courses. Args: blackboard_course_url: Blackboard course url. bbrouter: BbRouter cookie. load_all_recursively: If True, load all documents recursively. basic_auth: Basic auth credentials. cookies: Cookies. continue_on_failure: whether to continue loading the sitemap if an error occurs loading a url, emitting a warning instead of raising an exception. Setting this to True makes the loader more robust, but also may result in missing data. Default: False Raises: ValueError: If blackboard course url is invalid. """ super().__init__( web_paths=(blackboard_course_url), continue_on_failure=continue_on_failure ) # Get base url try: self.base_url = blackboard_course_url.split("/webapps/blackboard")[0] except IndexError: raise IndexError( "Invalid blackboard course url. " "Please provide a url that starts with " "https:///webapps/blackboard" ) if basic_auth is not None: self.session.auth = basic_auth # Combine cookies if cookies is None: cookies = {} cookies.update({"BbRouter": bbrouter}) self.session.cookies.update(cookies) self.load_all_recursively = load_all_recursively self.check_bs4() def check_bs4(self) -> None: """Check if BeautifulSoup4 is installed. Raises: ImportError: If BeautifulSoup4 is not installed. """ try: import bs4 # noqa: F401 except ImportError: raise ImportError( "BeautifulSoup4 is required for BlackboardLoader. " "Please install it with `pip install beautifulsoup4`." ) def load(self) -> List[Document]: """Load data into Document objects. Returns: List of Documents. """ if self.load_all_recursively: soup_info = self.scrape() self.folder_path = self._get_folder_path(soup_info) relative_paths = self._get_paths(soup_info) documents = [] for path in relative_paths: url = self.base_url + path print(f"Fetching documents from {url}") soup_info = self._scrape(url) with contextlib.suppress(ValueError): documents.extend(self._get_documents(soup_info)) return documents else: print(f"Fetching documents from {self.web_path}") soup_info = self.scrape() self.folder_path = self._get_folder_path(soup_info) return self._get_documents(soup_info) def _get_folder_path(self, soup: Any) -> str: """Get the folder path to save the Documents in. Args: soup: BeautifulSoup4 soup object. Returns: Folder path. """ # Get the course name course_name = soup.find("span", {"id": "crumb_1"}) if course_name is None: raise ValueError("No course name found.") course_name = course_name.text.strip() # Prepare the folder path course_name_clean = ( unquote(course_name) .replace(" ", "_") .replace("/", "_") .replace(":", "_") .replace(",", "_") .replace("?", "_") .replace("'", "_") .replace("!", "_") .replace('"', "_") ) # Get the folder path folder_path = Path(".") / course_name_clean return str(folder_path) def _get_documents(self, soup: Any) -> List[Document]: """Fetch content from page and return Documents. Args: soup: BeautifulSoup4 soup object. Returns: List of documents. """ attachments = self._get_attachments(soup) self._download_attachments(attachments) documents = self._load_documents() return documents def _get_attachments(self, soup: Any) -> List[str]: """Get all attachments from a page. Args: soup: BeautifulSoup4 soup object. Returns: List of attachments. """ from bs4 import BeautifulSoup, Tag # Get content list content_list = soup.find("ul", {"class": "contentList"}) if content_list is None: raise ValueError("No content list found.") content_list: BeautifulSoup # type: ignore # Get all attachments attachments = [] for attachment in content_list.find_all("ul", {"class": "attachments"}): attachment: Tag # type: ignore for link in attachment.find_all("a"): link: Tag # type: ignore href = link.get("href") # Only add if href is not None and does not start with # if href is not None and not href.startswith("#"): attachments.append(href) return attachments def _download_attachments(self, attachments: List[str]) -> None: """Download all attachments. Args: attachments: List of attachments. """ # Make sure the folder exists Path(self.folder_path).mkdir(parents=True, exist_ok=True) # Download all attachments for attachment in attachments: self.download(attachment) def _load_documents(self) -> List[Document]: """Load all documents in the folder. Returns: List of documents. """ # Create the document loader loader = DirectoryLoader( path=self.folder_path, glob="*.pdf", loader_cls=PyPDFLoader, # type: ignore ) # Load the documents documents = loader.load() # Return all documents return documents def _get_paths(self, soup: Any) -> List[str]: """Get all relative paths in the navbar.""" relative_paths = [] course_menu = soup.find("ul", {"class": "courseMenu"}) if course_menu is None: raise ValueError("No course menu found.") for link in course_menu.find_all("a"): href = link.get("href") if href is not None and href.startswith("/"): relative_paths.append(href) return relative_paths def download(self, path: str) -> None: """Download a file from an url. Args: path: Path to the file. """ # Get the file content response = self.session.get(self.base_url + path, allow_redirects=True) # Get the filename filename = self.parse_filename(response.url) # Write the file to disk with open(Path(self.folder_path) / filename, "wb") as f: f.write(response.content) def parse_filename(self, url: str) -> str: """Parse the filename from an url. Args: url: Url to parse the filename from. Returns: The filename. """ if (url_path := Path(url)) and url_path.suffix == ".pdf": return url_path.name else: return self._parse_filename_from_url(url) def _parse_filename_from_url(self, url: str) -> str: """Parse the filename from an url. Args: url: Url to parse the filename from. Returns: The filename. Raises: ValueError: If the filename could not be parsed. """ filename_matches = re.search(r"filename%2A%3DUTF-8%27%27(.+)", url) if filename_matches: filename = filename_matches.group(1) else: raise ValueError(f"Could not parse filename from {url}") if ".pdf" not in filename: raise ValueError(f"Incorrect file type: {filename}") filename = filename.split(".pdf")[0] + ".pdf" filename = unquote(filename) filename = filename.replace("%20", " ") return filename if __name__ == "__main__": loader = BlackboardLoader( "https:///webapps/blackboard/content/listContent.jsp?course_id=__1&content_id=__1&mode=reset", "", load_all_recursively=True, ) documents = loader.load() print(f"Loaded {len(documents)} pages of PDFs from {loader.web_path}")