"""Extractors for https://www.4chan.org/"""
from .common import Extractor, Message
from .. import text
class _4chanThreadExtractor(Extractor):
"""Extractor for 4chan threads"""
category = "4chan"
subcategory = "thread"
directory_fmt = ("{category}", "{board}", "{thread} {title}")
filename_fmt = "{tim} {filename}.{extension}"
archive_fmt = "{board}_{thread}_{tim}"
pattern = (r"(?:https?://)?boards\.4chan(?:nel)?\.org"
r"/([^/]+)/thread/(\d+)")
example = "https://boards.4channel.org/a/thread/12345/"
def __init__(self, match):
Extractor.__init__(self, match)
self.board, self.thread = match.groups()
def items(self):
url = f"https://a.4cdn.org/{self.board}/thread/{self.thread}.json"
posts = self.request_json(url)["posts"]
title = posts[0].get("sub") or text.remove_html(posts[0]["com"])
data = {
"board" : self.board,
"thread": self.thread,
"title" : text.unescape(title)[:50],
}
yield Message.Directory, data
for post in posts:
if "filename" in post:
post.update(data)
post["extension"] = post["ext"][1:]
post["filename"] = text.unescape(post["filename"])
post["_http_signature"] = _detect_null_byte
url = (f"https://i.4cdn.org"
f"/{post['board']}/{post['tim']}{post['ext']}")
yield Message.Url, url, post
def _detect_null_byte(signature):
"""Return False if all file signature bytes are null"""
if signature:
if signature[0]:
return True
for byte in signature:
if byte:
return True
return "File data consists of null bytes"
class _4chanBoardExtractor(Extractor):
"""Extractor for 4chan boards"""
category = "4chan"
subcategory = "board"
pattern = r"(?:https?://)?boards\.4chan(?:nel)?\.org/([^/?#]+)/\d*$"
example = "https://boards.4channel.org/a/"
def __init__(self, match):
Extractor.__init__(self, match)
self.board = match[1]
def items(self):
url = f"https://a.4cdn.org/{self.board}/threads.json"
threads = self.request_json(url)
for page in threads:
for thread in page["threads"]:
url = (f"https://boards.4chan.org"
f"/{self.board}/thread/{thread['no']}/")
thread["page"] = page["page"]
thread["_extractor"] = _4chanThreadExtractor
yield Message.Queue, url, thread
