Source code for granary.as1

"""Utilities for ActivityStreams 1 objects."""
import collections
import logging
from operator import itemgetter
import re

from oauth_dropins.webutil import util

logger = logging.getLogger(__name__)

# maps each AS1 RSVP verb to the collection inside an event object that the
# RSVPing actor would go into.
RSVP_VERB_TO_COLLECTION = collections.OrderedDict((  # in priority order
  ('rsvp-yes', 'attending'),
  ('rsvp-no', 'notAttending'),
  ('rsvp-maybe', 'maybeAttending'),
  ('rsvp-interested', 'interested'),
  ('invite', 'invited'),
))
VERBS_WITH_OBJECT = {
  'follow',
  'like',
  'react',
  'repost',
  'share',
} | set(RSVP_VERB_TO_COLLECTION.keys())

# used in original_post_discovery
_PERMASHORTCITATION_RE = re.compile(r'\(([^:\s)]+\.[^\s)]{2,})[ /]([^\s)]+)\)$')


[docs]def object_type(obj): """Returns the object type, or the verb if it's an activity object. Details: http://activitystrea.ms/specs/json/1.0/#activity-object Args: obj: decoded JSON ActivityStreams object Returns: string: ActivityStreams object type """ type = obj.get('objectType') return type if type and type != 'activity' else obj.get('verb')
[docs]def merge_by_id(obj, field, new): """Merges new items by id into a field in an existing AS1 object. Merges new items by id into the given field. If it exists, it must be a list. Requires all existing and new items in the field to have ids. Args: obj: dict, AS1 object field: str, name of field to merge new items into new: sequence of AS1 dicts """ merged = {o['id']: o for o in obj.get(field, []) + new} obj[field] = sorted(merged.values(), key=itemgetter('id'))
[docs]def is_public(obj): """Returns True if the object is public, False if private, None if unknown. ...according to the Audience Targeting extension: http://activitystrea.ms/specs/json/targeting/1.0/ Expects values generated by this library: objectType group, alias @public, @unlisted, or @private. Also, important point: this defaults to true, ie public. Bridgy depends on that and prunes the to field from stored activities in Response objects (in bridgy/util.prune_activity()). If the default here ever changes, be sure to update Bridgy's code. """ to = obj.get('to') or obj.get('object', {}).get('to') or [] aliases = util.trim_nulls([t.get('alias') for t in to]) object_types = util.trim_nulls([t.get('objectType') for t in to]) return (True if '@public' in aliases or '@unlisted' in aliases else None if 'unknown' in object_types else False if aliases else True)
[docs]def add_rsvps_to_event(event, rsvps): """Adds RSVP objects to an event's attending fields, in place. Args: event: ActivityStreams event object rsvps: sequence of ActivityStreams RSVP activity objects """ for rsvp in rsvps: field = RSVP_VERB_TO_COLLECTION.get(rsvp.get('verb')) if field: event.setdefault(field, []).append(rsvp.get( 'object' if field == 'invited' else 'actor'))
[docs]def get_rsvps_from_event(event): """Returns RSVP objects for an event's attending fields. Args: event: ActivityStreams event object Returns: sequence of ActivityStreams RSVP activity objects """ id = event.get('id') if not id: return [] parsed = util.parse_tag_uri(id) if not parsed: return [] domain, event_id = parsed url = event.get('url') author = event.get('author') rsvps = [] for verb, field in RSVP_VERB_TO_COLLECTION.items(): for actor in event.get(field, []): rsvp = {'objectType': 'activity', 'verb': verb, 'object' if verb == 'invite' else 'actor': actor, 'url': url, } if event_id and 'id' in actor: _, actor_id = util.parse_tag_uri(actor['id']) rsvp['id'] = util.tag_uri(domain, f'{event_id}_rsvp_{actor_id}') if url: rsvp['url'] = '#'.join((url, actor_id)) if verb == 'invite' and author: rsvp['actor'] = author rsvps.append(rsvp) return rsvps
[docs]def activity_changed(before, after, log=False): """Returns whether two activities or objects differ meaningfully. Only compares a few fields: object type, verb, content, location, and image. Notably does *not* compare author and published/updated timestamps. This has been tested on Facebook posts, comments, and event RSVPs (only content and rsvp_status change) and Google+ posts and comments (content, updated, and etag change). Twitter tweets and Instagram photo captions and comments can't be edited. Args: before, after: dicts, ActivityStreams activities or objects Returns: boolean """ def changed(b, a, field, label): b_val = b.get(field) a_val = a.get(field) if b_val != a_val and (a_val or b_val): if log: logger.debug(f'{label}[{field}] {b_val} => {a_val}') return True obj_b = before.get('object', {}) obj_a = after.get('object', {}) return any(changed(before, after, field, 'activity') or changed(obj_b, obj_a, field, 'activity[object]') for field in ('objectType', 'verb', 'to', 'content', 'location', 'image', 'inReplyTo'))
[docs]def append_in_reply_to(before, after): """Appends the inReplyTos from the before object to the after object, in place Args: before, after: dicts, ActivityStreams activities or objects """ obj_b = before.get('object', before) obj_a = after.get('object', after) if obj_b and obj_a: reply_b = util.get_list(obj_b, 'inReplyTo') reply_a = util.get_list(obj_a, 'inReplyTo') obj_a['inReplyTo'] = util.dedupe_urls(reply_a + reply_b)
[docs]def actor_name(actor): """Returns the given actor's name if available, otherwise Unknown.""" if actor: return actor.get('displayName') or actor.get('username') or 'Unknown' return 'Unknown'
[docs]def original_post_discovery( activity, domains=None, include_redirect_sources=True, include_reserved_hosts=True, max_redirect_fetches=None, **kwargs): """Discovers original post links. This is a variation on http://indiewebcamp.com/original-post-discovery . It differs in that it finds multiple candidate links instead of one, and it doesn't bother looking for MF2 (etc) markup because the silos don't let you input it. More background: https://github.com/snarfed/bridgy/issues/51#issuecomment-136018857 Original post candidates come from the upstreamDuplicates, attachments, and tags fields, as well as links and permashortlinks/permashortcitations in the text content. Args: activity: activity dict domains: optional sequence of domains. If provided, only links to these domains will be considered original and stored in upstreamDuplicates. (Permashortcitations are exempt.) include_redirect_sources: boolean, whether to include URLs that redirect as well as their final destination URLs include_reserved_hosts: boolean, whether to include domains on reserved TLDs (eg foo.example) and local hosts (eg http://foo.local/, http://my-server/) max_redirect_fetches: if specified, only make up to this many HTTP fetches to resolve redirects. kwargs: passed to requests.head() when following redirects Returns: ([string original post URLs], [string mention URLs]) tuple """ obj = activity.get('object') or activity content = obj.get('content', '').strip() # find all candidate URLs tags = [t.get('url') for t in obj.get('attachments', []) + obj.get('tags', []) if t.get('objectType') in ('article', 'mention', 'note', None)] candidates = (tags + util.extract_links(content) + obj.get('upstreamDuplicates', []) + util.get_list(obj, 'targetUrl')) # Permashortcitations (http://indiewebcamp.com/permashortcitation) are short # references to canonical copies of a given (usually syndicated) post, of # the form (DOMAIN PATH). We consider them an explicit original post link. candidates += [match.expand(r'http://\1/\2') for match in _PERMASHORTCITATION_RE.finditer(content)] candidates = util.dedupe_urls( util.clean_url(url) for url in candidates if url and (url.startswith('http://') or url.startswith('https://')) and # heuristic: ellipsized URLs are probably incomplete, so omit them. not url.endswith('...') and not url.endswith('…')) # check for redirect and add their final urls if max_redirect_fetches and len(candidates) > max_redirect_fetches: logger.warning('Found {len(candidates)} original post candidates, only resolving redirects for the first {max_redirect_fetches}') redirects = {} # maps final URL to original URL for redirects for url in candidates[:max_redirect_fetches]: resolved = util.follow_redirects(url, **kwargs) if (resolved.url != url and resolved.headers.get('content-type', '').startswith('text/html')): redirects[resolved.url] = url candidates.extend(redirects.keys()) # use domains to determine which URLs are original post links vs mentions originals = set() mentions = set() for url in util.dedupe_urls(candidates): if url in redirects.values(): # this is a redirected original URL. postpone and handle it when we hit # its final URL so that we know the final domain. continue domain = util.domain_from_link(url) if not domain: continue if not include_reserved_hosts and ( ('.' not in domain or domain.split('.')[-1] in (util.RESERVED_TLDS | util.LOCAL_TLDS))): continue which = (originals if not domains or util.domain_or_parent_in(domain, domains) else mentions) which.add(url) redirected_from = redirects.get(url) if redirected_from and include_redirect_sources: which.add(redirected_from) logger.info(f'Original post discovery found original posts {originals}, mentions {mentions}') return originals, mentions