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
[docs]
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()
"""
[docs]
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,
show_progress: bool = True,
):
"""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
show_progress: whether to show a progress bar while loading. Default: True
Raises:
ValueError: If blackboard course url is invalid.
"""
super().__init__(
web_paths=(blackboard_course_url),
continue_on_failure=continue_on_failure,
show_progress=show_progress,
)
# 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://<blackboard_url>/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()
[docs]
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`."
)
[docs]
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}") # noqa: T201
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}") # noqa: T201
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: BeautifulSoup
content_list = soup.find("ul", {"class": "contentList"})
if content_list is None:
raise ValueError("No content list found.")
# Get all attachments
attachments = []
attachment: Tag
for attachment in content_list.find_all("ul", {"class": "attachments"}):
link: Tag
for link in attachment.find_all("a"):
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
[docs]
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)
[docs]
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://<YOUR BLACKBOARD URL"
" HERE>/webapps/blackboard/content/listContent.jsp?course_id=_<YOUR COURSE ID"
" HERE>_1&content_id=_<YOUR CONTENT ID HERE>_1&mode=reset",
"<YOUR BBROUTER COOKIE HERE>",
load_all_recursively=True,
)
documents = loader.load()
print(f"Loaded {len(documents)} pages of PDFs from {loader.web_path}") # noqa: T201
