Add support for Facebook user profiles

socialmediascraper/modules/facebook.py

@@ -0,0 +1,77 @@
+import bs4
+import json
+import logging
+import re
+import socialmediascraper.base
+import urllib.parse
+
+
+logger = logging.getLogger(__name__)
+
+
+class FacebookUserScraper(socialmediascraper.base.Scraper):
+	name = 'facebook-user'
+
+	def __init__(self, username, **kwargs):
+		super().__init__(**kwargs)
+		self._username = username
+
+	def _soup_to_items(self, soup, username, baseUrl):
+		yielded = set()
+		for a in soup.find_all('a', href = re.compile(r'^/[^/]+/(posts|photos|videos)/[^/]*\d')):
+			href = a.get('href')
+			if href.startswith(f'/{username}/'):
+				link = urllib.parse.urljoin(baseUrl, href)
+				if link not in yielded:
+					yield link
+					yielded.add(link)
+
+	def get_items(self):
+		headers = {'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/39.0.2171.95 Safari/537.36'}
+
+		nextPageLinkPattern = re.compile(r'^/pages_reaction_units/more/\?page_id=')
+		spuriousForLoopPattern = re.compile(r'^for \(;;\);')
+
+		logger.info('Retrieving initial data')
+		baseUrl = f'https://www.facebook.com/{self._username}/'
+		r = self._get(baseUrl, headers = headers)
+		if r.status_code == 404:
+			logger.warning('User does not exist')
+			return
+		elif r.status_code != 200:
+			logger.error('Got status code {r.status_code}')
+			return
+		soup = bs4.BeautifulSoup(r.text, 'lxml')
+		username = re.sub(r'^https://www\.facebook\.com/([^/]+)/$', r'\1', soup.find('link').get('href')) # Canonical capitalisation
+		baseUrl = f'https://www.facebook.com/{username}/'
+		yield from self._soup_to_items(soup, username, baseUrl)
+		nextPageLink = soup.find('a', ajaxify = nextPageLinkPattern)
+
+		while nextPageLink:
+			logger.info('Retrieving next page')
+
+			# The web app sends a bunch of additional parameters. Most of them would be easy to add, but there's also __dyn, which is a compressed list of the "modules" loaded in the browser.
+			# Reproducing that would be difficult to get right, especially as Facebook's codebase evolves, so it's just not sent at all here.
+			r = self._get(urllib.parse.urljoin(baseUrl, nextPageLink.get('ajaxify')) + '&__a=1', headers = headers)
+			if r.status_code != 200:
+				logger.error(f'Got status code {r.status_code}')
+				return
+			response = json.loads(spuriousForLoopPattern.sub('', r.text))
+			assert 'domops' in response
+			assert len(response['domops']) == 1
+			assert len(response['domops'][0]) == 4
+			assert response['domops'][0][0] == 'replace', f'{response["domops"][0]} is not "replace"'
+			assert response['domops'][0][1] == '#www_pages_reaction_see_more_unitwww_pages_home'
+			assert response['domops'][0][2] == False
+			assert '__html' in response['domops'][0][3]
+			soup = bs4.BeautifulSoup(response['domops'][0][3]['__html'], 'lxml')
+			yield from self._soup_to_items(soup, username, baseUrl)
+			nextPageLink = soup.find('a', ajaxify = nextPageLinkPattern)
+
+	@classmethod
+	def setup_parser(cls, subparser):
+		subparser.add_argument('username', help = 'A Facebook username or user ID')
+
+	@classmethod
+	def from_args(cls, args):
+		return cls(args.username, retries = args.retries)