# See https://zulip.readthedocs.io/en/latest/subsystems/events-system.html for # high-level documentation on how this system works. import copy import ujson from collections import defaultdict from django.utils.translation import ugettext as _ from django.conf import settings from importlib import import_module from typing import ( cast, Any, Callable, Dict, Iterable, List, Optional, Sequence, Set, Tuple, Union ) session_engine = import_module(settings.SESSION_ENGINE) from zerver.lib.alert_words import user_alert_words from zerver.lib.attachments import user_attachments from zerver.lib.avatar import avatar_url, get_avatar_field from zerver.lib.bot_config import load_bot_config_template from zerver.lib.hotspots import get_next_hotspots from zerver.lib.integrations import EMBEDDED_BOTS from zerver.lib.message import ( aggregate_unread_data, apply_unread_message_event, get_raw_unread_data, get_starred_message_ids, ) from zerver.lib.narrow import check_supported_events_narrow_filter from zerver.lib.push_notifications import push_notifications_enabled from zerver.lib.soft_deactivation import maybe_catch_up_soft_deactivated_user from zerver.lib.realm_icon import realm_icon_url from zerver.lib.request import JsonableError from zerver.lib.topic import TOPIC_NAME from zerver.lib.topic_mutes import get_topic_mutes from zerver.lib.actions import ( validate_user_access_to_subscribers_helper, do_get_streams, get_default_streams_for_realm, gather_subscriptions_helper, get_cross_realm_dicts, get_status_dict, streams_to_dicts_sorted, default_stream_groups_to_dicts_sorted, get_owned_bot_dicts, ) from zerver.lib.user_groups import user_groups_in_realm_serialized from zerver.tornado.event_queue import request_event_queue, get_user_events from zerver.models import Client, Message, Realm, UserPresence, UserProfile, CustomProfileFieldValue, \ get_user_profile_by_id, \ get_realm_user_dicts, realm_filters_for_realm, get_user,\ custom_profile_fields_for_realm, get_realm_domains, \ get_default_stream_groups, CustomProfileField, Stream from zproject.backends import email_auth_enabled, password_auth_enabled from version import ZULIP_VERSION def get_raw_user_data(realm_id: int, client_gravatar: bool) -> Dict[int, Dict[str, str]]: user_dicts = get_realm_user_dicts(realm_id) # TODO: Consider optimizing this query away with caching. custom_profile_field_values = CustomProfileFieldValue.objects.filter(user_profile__realm_id=realm_id) profiles_by_user_id = defaultdict(dict) # type: Dict[int, Dict[str, Any]] for profile_field in custom_profile_field_values: user_id = profile_field.user_profile_id profiles_by_user_id[user_id][profile_field.field_id] = profile_field.value def user_data(row: Dict[str, Any]) -> Dict[str, Any]: avatar_url = get_avatar_field( user_id=row['id'], realm_id= realm_id, email=row['email'], avatar_source=row['avatar_source'], avatar_version=row['avatar_version'], medium=False, client_gravatar=client_gravatar, ) is_admin = row['is_realm_admin'] is_guest = row['is_guest'] is_bot = row['is_bot'] # This format should align with get_cross_realm_dicts() and notify_created_user result = dict( email=row['email'], user_id=row['id'], avatar_url=avatar_url, is_admin=is_admin, is_guest=is_guest, is_bot=is_bot, full_name=row['full_name'], timezone=row['timezone'], is_active = row['is_active'], date_joined = row['date_joined'].isoformat(), ) if not is_bot: result['profile_data'] = profiles_by_user_id.get(row['id'], {}) return result return { row['id']: user_data(row) for row in user_dicts } def always_want(msg_type: str) -> bool: ''' This function is used as a helper in fetch_initial_state_data, when the user passes in None for event_types, and we want to fetch info for every event type. Defining this at module level makes it easier to mock. ''' return True # Fetch initial data. When event_types is not specified, clients want # all event types. Whenever you add new code to this function, you # should also add corresponding events for changes in the data # structures and new code to apply_events (and add a test in EventsRegisterTest). def fetch_initial_state_data(user_profile: UserProfile, event_types: Optional[Iterable[str]], queue_id: str, client_gravatar: bool, include_subscribers: bool = True) -> Dict[str, Any]: state = {'queue_id': queue_id} # type: Dict[str, Any] realm = user_profile.realm if event_types is None: # return True always want = always_want # type: Callable[[str], bool] else: want = set(event_types).__contains__ if want('alert_words'): state['alert_words'] = user_alert_words(user_profile) if want('custom_profile_fields'): fields = custom_profile_fields_for_realm(realm.id) state['custom_profile_fields'] = [f.as_dict() for f in fields] state['custom_profile_field_types'] = CustomProfileField.FIELD_TYPE_CHOICES_DICT if want('hotspots'): state['hotspots'] = get_next_hotspots(user_profile) if want('message'): # The client should use get_messages() to fetch messages # starting with the max_message_id. They will get messages # newer than that ID via get_events() messages = Message.objects.filter(usermessage__user_profile=user_profile).order_by('-id')[:1] if messages: state['max_message_id'] = messages[0].id else: state['max_message_id'] = -1 if want('muted_topics'): state['muted_topics'] = get_topic_mutes(user_profile) if want('pointer'): state['pointer'] = user_profile.pointer if want('presence'): state['presences'] = get_status_dict(user_profile) if want('realm'): for property_name in Realm.property_types: state['realm_' + property_name] = getattr(realm, property_name) # Most state is handled via the property_types framework; # these manual entries are for those realm settings that don't # fit into that framework. state['realm_authentication_methods'] = realm.authentication_methods_dict() state['realm_allow_message_editing'] = realm.allow_message_editing state['realm_allow_community_topic_editing'] = realm.allow_community_topic_editing state['realm_allow_message_deleting'] = realm.allow_message_deleting state['realm_message_content_edit_limit_seconds'] = realm.message_content_edit_limit_seconds state['realm_message_content_delete_limit_seconds'] = realm.message_content_delete_limit_seconds state['realm_icon_url'] = realm_icon_url(realm) state['realm_icon_source'] = realm.icon_source state['max_icon_file_size'] = settings.MAX_ICON_FILE_SIZE state['realm_bot_domain'] = realm.get_bot_domain() state['realm_uri'] = realm.uri state['realm_available_video_chat_providers'] = realm.VIDEO_CHAT_PROVIDERS state['realm_presence_disabled'] = realm.presence_disabled state['realm_digest_emails_enabled'] = realm.digest_emails_enabled and settings.SEND_DIGEST_EMAILS state['realm_is_zephyr_mirror_realm'] = realm.is_zephyr_mirror_realm state['realm_email_auth_enabled'] = email_auth_enabled(realm) state['realm_password_auth_enabled'] = password_auth_enabled(realm) state['realm_push_notifications_enabled'] = push_notifications_enabled() if realm.notifications_stream and not realm.notifications_stream.deactivated: notifications_stream = realm.notifications_stream state['realm_notifications_stream_id'] = notifications_stream.id else: state['realm_notifications_stream_id'] = -1 signup_notifications_stream = realm.get_signup_notifications_stream() if signup_notifications_stream: state['realm_signup_notifications_stream_id'] = signup_notifications_stream.id else: state['realm_signup_notifications_stream_id'] = -1 if want('realm_domains'): state['realm_domains'] = get_realm_domains(realm) if want('realm_emoji'): state['realm_emoji'] = realm.get_emoji() if want('realm_filters'): state['realm_filters'] = realm_filters_for_realm(realm.id) if want('realm_user_groups'): state['realm_user_groups'] = user_groups_in_realm_serialized(realm) if want('realm_user'): state['raw_users'] = get_raw_user_data( realm_id=realm.id, client_gravatar=client_gravatar, ) # For the user's own avatar URL, we force # client_gravatar=False, since that saves some unnecessary # client-side code for handing medium-size avatars. See #8253 # for details. state['avatar_source'] = user_profile.avatar_source state['avatar_url_medium'] = avatar_url( user_profile, medium=True, client_gravatar=False, ) state['avatar_url'] = avatar_url( user_profile, medium=False, client_gravatar=False, ) state['can_create_streams'] = user_profile.can_create_streams() state['can_subscribe_other_users'] = user_profile.can_subscribe_other_users() state['cross_realm_bots'] = list(get_cross_realm_dicts()) state['is_admin'] = user_profile.is_realm_admin state['is_guest'] = user_profile.is_guest state['user_id'] = user_profile.id state['enter_sends'] = user_profile.enter_sends state['email'] = user_profile.email state['delivery_email'] = user_profile.delivery_email state['full_name'] = user_profile.full_name if want('realm_bot'): state['realm_bots'] = get_owned_bot_dicts(user_profile) # This does not yet have an apply_event counterpart, since currently, # new entries for EMBEDDED_BOTS can only be added directly in the codebase. if want('realm_embedded_bots'): realm_embedded_bots = [] for bot in EMBEDDED_BOTS: realm_embedded_bots.append({'name': bot.name, 'config': load_bot_config_template(bot.name)}) state['realm_embedded_bots'] = realm_embedded_bots if want('subscription'): subscriptions, unsubscribed, never_subscribed = gather_subscriptions_helper( user_profile, include_subscribers=include_subscribers) state['subscriptions'] = subscriptions state['unsubscribed'] = unsubscribed state['never_subscribed'] = never_subscribed if want('update_message_flags') and want('message'): # Keeping unread_msgs updated requires both message flag updates and # message updates. This is due to the fact that new messages will not # generate a flag update so we need to use the flags field in the # message event. state['raw_unread_msgs'] = get_raw_unread_data(user_profile) if want('starred_messages'): state['starred_messages'] = get_starred_message_ids(user_profile) if want('stream'): state['streams'] = do_get_streams(user_profile) state['stream_name_max_length'] = Stream.MAX_NAME_LENGTH state['stream_description_max_length'] = Stream.MAX_DESCRIPTION_LENGTH if want('default_streams'): state['realm_default_streams'] = streams_to_dicts_sorted( get_default_streams_for_realm(realm.id)) if want('default_stream_groups'): state['realm_default_stream_groups'] = default_stream_groups_to_dicts_sorted( get_default_stream_groups(realm)) if want('update_display_settings'): for prop in UserProfile.property_types: state[prop] = getattr(user_profile, prop) state['emojiset_choices'] = user_profile.emojiset_choices() if want('update_global_notifications'): for notification in UserProfile.notification_setting_types: state[notification] = getattr(user_profile, notification) if want('zulip_version'): state['zulip_version'] = ZULIP_VERSION return state def remove_message_id_from_unread_mgs(state: Dict[str, Dict[str, Any]], message_id: int) -> None: raw_unread = state['raw_unread_msgs'] for key in ['pm_dict', 'stream_dict', 'huddle_dict']: raw_unread[key].pop(message_id, None) raw_unread['unmuted_stream_msgs'].discard(message_id) raw_unread['mentions'].discard(message_id) def apply_events(state: Dict[str, Any], events: Iterable[Dict[str, Any]], user_profile: UserProfile, client_gravatar: bool, include_subscribers: bool = True, fetch_event_types: Optional[Iterable[str]] = None) -> None: for event in events: if fetch_event_types is not None and event['type'] not in fetch_event_types: # TODO: continuing here is not, most precisely, correct. # In theory, an event of one type, e.g. `realm_user`, # could modify state that doesn't come from that # `fetch_event_types` value, e.g. the `our_person` part of # that code path. But it should be extremely rare, and # fixing that will require a nontrivial refactor of # `apply_event`. For now, be careful in your choice of # `fetch_event_types`. continue apply_event(state, event, user_profile, client_gravatar, include_subscribers) def apply_event(state: Dict[str, Any], event: Dict[str, Any], user_profile: UserProfile, client_gravatar: bool, include_subscribers: bool) -> None: if event['type'] == "message": state['max_message_id'] = max(state['max_message_id'], event['message']['id']) if 'raw_unread_msgs' in state: apply_unread_message_event( user_profile, state['raw_unread_msgs'], event['message'], event['flags'], ) elif event['type'] == "hotspots": state['hotspots'] = event['hotspots'] elif event['type'] == "custom_profile_fields": state['custom_profile_fields'] = event['fields'] elif event['type'] == "pointer": state['pointer'] = max(state['pointer'], event['pointer']) elif event['type'] == "realm_user": person = event['person'] person_user_id = person['user_id'] if event['op'] == "add": person = copy.deepcopy(person) if client_gravatar: if 'gravatar.com' in person['avatar_url']: person['avatar_url'] = None person['is_active'] = True if not person['is_bot']: person['profile_data'] = {} state['raw_users'][person_user_id] = person elif event['op'] == "remove": state['raw_users'][person_user_id]['is_active'] = False elif event['op'] == 'update': is_me = (person_user_id == user_profile.id) if is_me: if ('avatar_url' in person and 'avatar_url' in state): state['avatar_source'] = person['avatar_source'] state['avatar_url'] = person['avatar_url'] state['avatar_url_medium'] = person['avatar_url_medium'] for field in ['is_admin', 'email', 'full_name']: if field in person and field in state: state[field] = person[field] # In the unlikely event that the current user # just changed to/from being an admin, we need # to add/remove the data on all bots in the # realm. This is ugly and probably better # solved by removing the all-realm-bots data # given to admin users from this flow. if ('is_admin' in person and 'realm_bots' in state): prev_state = state['raw_users'][user_profile.id] was_admin = prev_state['is_admin'] now_admin = person['is_admin'] if was_admin and not now_admin: state['realm_bots'] = [] if not was_admin and now_admin: state['realm_bots'] = get_owned_bot_dicts(user_profile) if client_gravatar and 'avatar_url' in person: # Respect the client_gravatar setting in the `users` data. if 'gravatar.com' in person['avatar_url']: person['avatar_url'] = None person['avatar_url_medium'] = None if person_user_id in state['raw_users']: p = state['raw_users'][person_user_id] for field in p: if field in person: p[field] = person[field] if 'custom_profile_field' in person: custom_field_id = person['custom_profile_field']['id'] custom_field_new_value = person['custom_profile_field']['value'] p['profile_data'][custom_field_id] = custom_field_new_value elif event['type'] == 'realm_bot': if event['op'] == 'add': state['realm_bots'].append(event['bot']) if event['op'] == 'remove': email = event['bot']['email'] for bot in state['realm_bots']: if bot['email'] == email: bot['is_active'] = False if event['op'] == 'delete': state['realm_bots'] = [item for item in state['realm_bots'] if item['email'] != event['bot']['email']] if event['op'] == 'update': for bot in state['realm_bots']: if bot['email'] == event['bot']['email']: if 'owner_id' in event['bot']: bot['owner'] = get_user_profile_by_id(event['bot']['owner_id']).email else: bot.update(event['bot']) elif event['type'] == 'stream': if event['op'] == 'create': for stream in event['streams']: if not stream['invite_only']: stream_data = copy.deepcopy(stream) if include_subscribers: stream_data['subscribers'] = [] stream_data['stream_weekly_traffic'] = None stream_data['is_old_stream'] = False stream_data['is_announcement_only'] = False # Add stream to never_subscribed (if not invite_only) state['never_subscribed'].append(stream_data) state['streams'].append(stream) state['streams'].sort(key=lambda elt: elt["name"]) if event['op'] == 'delete': deleted_stream_ids = {stream['stream_id'] for stream in event['streams']} state['streams'] = [s for s in state['streams'] if s['stream_id'] not in deleted_stream_ids] state['never_subscribed'] = [stream for stream in state['never_subscribed'] if stream['stream_id'] not in deleted_stream_ids] if event['op'] == 'update': # For legacy reasons, we call stream data 'subscriptions' in # the state var here, for the benefit of the JS code. for obj in state['subscriptions']: if obj['name'].lower() == event['name'].lower(): obj[event['property']] = event['value'] # Also update the pure streams data for stream in state['streams']: if stream['name'].lower() == event['name'].lower(): prop = event['property'] if prop in stream: stream[prop] = event['value'] elif event['op'] == "occupy": state['streams'] += event['streams'] elif event['op'] == "vacate": stream_ids = [s["stream_id"] for s in event['streams']] state['streams'] = [s for s in state['streams'] if s["stream_id"] not in stream_ids] elif event['type'] == 'default_streams': state['realm_default_streams'] = event['default_streams'] elif event['type'] == 'default_stream_groups': state['realm_default_stream_groups'] = event['default_stream_groups'] elif event['type'] == 'realm': if event['op'] == "update": field = 'realm_' + event['property'] state[field] = event['value'] # Tricky interaction: Whether we can create streams can get changed here. if (field in ['realm_create_stream_by_admins_only', 'realm_waiting_period_threshold']) and 'can_create_streams' in state: state['can_create_streams'] = user_profile.can_create_streams() state['can_subscribe_other_users'] = user_profile.can_subscribe_other_users() elif event['op'] == "update_dict": for key, value in event['data'].items(): state['realm_' + key] = value # It's a bit messy, but this is where we need to # update the state for whether password authentication # is enabled on this server. if key == 'authentication_methods': state['realm_password_auth_enabled'] = (value['Email'] or value['LDAP']) state['realm_email_auth_enabled'] = value['Email'] elif event['type'] == "subscription": if not include_subscribers and event['op'] in ['peer_add', 'peer_remove']: return if event['op'] in ["add"]: if not include_subscribers: # Avoid letting 'subscribers' entries end up in the list for i, sub in enumerate(event['subscriptions']): event['subscriptions'][i] = copy.deepcopy(event['subscriptions'][i]) del event['subscriptions'][i]['subscribers'] def name(sub: Dict[str, Any]) -> str: return sub['name'].lower() if event['op'] == "add": added_names = set(map(name, event["subscriptions"])) was_added = lambda s: name(s) in added_names # add the new subscriptions state['subscriptions'] += event['subscriptions'] # remove them from unsubscribed if they had been there state['unsubscribed'] = [s for s in state['unsubscribed'] if not was_added(s)] # remove them from never_subscribed if they had been there state['never_subscribed'] = [s for s in state['never_subscribed'] if not was_added(s)] elif event['op'] == "remove": removed_names = set(map(name, event["subscriptions"])) was_removed = lambda s: name(s) in removed_names # Find the subs we are affecting. removed_subs = list(filter(was_removed, state['subscriptions'])) # Remove our user from the subscribers of the removed subscriptions. if include_subscribers: for sub in removed_subs: sub['subscribers'] = [id for id in sub['subscribers'] if id != user_profile.id] # We must effectively copy the removed subscriptions from subscriptions to # unsubscribe, since we only have the name in our data structure. state['unsubscribed'] += removed_subs # Now filter out the removed subscriptions from subscriptions. state['subscriptions'] = [s for s in state['subscriptions'] if not was_removed(s)] elif event['op'] == 'update': for sub in state['subscriptions']: if sub['name'].lower() == event['name'].lower(): sub[event['property']] = event['value'] elif event['op'] == 'peer_add': user_id = event['user_id'] for sub in state['subscriptions']: if (sub['name'] in event['subscriptions'] and user_id not in sub['subscribers']): sub['subscribers'].append(user_id) for sub in state['never_subscribed']: if (sub['name'] in event['subscriptions'] and user_id not in sub['subscribers']): sub['subscribers'].append(user_id) elif event['op'] == 'peer_remove': user_id = event['user_id'] for sub in state['subscriptions']: if (sub['name'] in event['subscriptions'] and user_id in sub['subscribers']): sub['subscribers'].remove(user_id) elif event['type'] == "presence": # TODO: Add user_id to presence update events / state format! presence_user_profile = get_user(event['email'], user_profile.realm) state['presences'][event['email']] = UserPresence.get_status_dict_by_user( presence_user_profile)[event['email']] elif event['type'] == "update_message": # We don't return messages in /register, so we don't need to # do anything for content updates, but we may need to update # the unread_msgs data if the topic of an unread message changed. if TOPIC_NAME in event: stream_dict = state['raw_unread_msgs']['stream_dict'] topic = event[TOPIC_NAME] for message_id in event['message_ids']: if message_id in stream_dict: stream_dict[message_id]['topic'] = topic elif event['type'] == "delete_message": max_message = Message.objects.filter( usermessage__user_profile=user_profile).order_by('-id').first() if max_message: state['max_message_id'] = max_message.id else: state['max_message_id'] = -1 remove_id = event['message_id'] remove_message_id_from_unread_mgs(state, remove_id) elif event['type'] == "reaction": # The client will get the message with the reactions directly pass elif event['type'] == "submessage": # The client will get submessages with their messages pass elif event['type'] == 'typing': # Typing notification events are transient and thus ignored pass elif event['type'] == "attachment": # Attachment events are just for updating the "uploads" UI; # they are not sent directly. pass elif event['type'] == "update_message_flags": # We don't return messages in `/register`, so most flags we # can ignore, but we do need to update the unread_msgs data if # unread state is changed. if event['flag'] == 'read' and event['operation'] == 'add': for remove_id in event['messages']: remove_message_id_from_unread_mgs(state, remove_id) if event['flag'] == 'starred' and event['operation'] == 'add': state['starred_messages'] += event['messages'] if event['flag'] == 'starred' and event['operation'] == 'remove': state['starred_messages'] = [message for message in state['starred_messages'] if not (message in event['messages'])] elif event['type'] == "realm_domains": if event['op'] == 'add': state['realm_domains'].append(event['realm_domain']) elif event['op'] == 'change': for realm_domain in state['realm_domains']: if realm_domain['domain'] == event['realm_domain']['domain']: realm_domain['allow_subdomains'] = event['realm_domain']['allow_subdomains'] elif event['op'] == 'remove': state['realm_domains'] = [realm_domain for realm_domain in state['realm_domains'] if realm_domain['domain'] != event['domain']] elif event['type'] == "realm_emoji": state['realm_emoji'] = event['realm_emoji'] elif event['type'] == "alert_words": state['alert_words'] = event['alert_words'] elif event['type'] == "muted_topics": state['muted_topics'] = event["muted_topics"] elif event['type'] == "realm_filters": state['realm_filters'] = event["realm_filters"] elif event['type'] == "update_display_settings": assert event['setting_name'] in UserProfile.property_types state[event['setting_name']] = event['setting'] elif event['type'] == "update_global_notifications": assert event['notification_name'] in UserProfile.notification_setting_types state[event['notification_name']] = event['setting'] elif event['type'] == "invites_changed": pass elif event['type'] == "user_group": if event['op'] == 'add': state['realm_user_groups'].append(event['group']) state['realm_user_groups'].sort(key=lambda group: group['id']) elif event['op'] == 'update': for user_group in state['realm_user_groups']: if user_group['id'] == event['group_id']: user_group.update(event['data']) elif event['op'] == 'add_members': for user_group in state['realm_user_groups']: if user_group['id'] == event['group_id']: user_group['members'].extend(event['user_ids']) user_group['members'].sort() elif event['op'] == 'remove_members': for user_group in state['realm_user_groups']: if user_group['id'] == event['group_id']: members = set(user_group['members']) user_group['members'] = list(members - set(event['user_ids'])) user_group['members'].sort() elif event['op'] == 'remove': state['realm_user_groups'] = [ug for ug in state['realm_user_groups'] if ug['id'] != event['group_id']] else: raise AssertionError("Unexpected event type %s" % (event['type'],)) def do_events_register(user_profile: UserProfile, user_client: Client, apply_markdown: bool = True, client_gravatar: bool = False, event_types: Optional[Iterable[str]] = None, queue_lifespan_secs: int = 0, all_public_streams: bool = False, include_subscribers: bool = True, narrow: Iterable[Sequence[str]] = [], fetch_event_types: Optional[Iterable[str]] = None) -> Dict[str, Any]: # Technically we don't need to check this here because # build_narrow_filter will check it, but it's nicer from an error # handling perspective to do it before contacting Tornado check_supported_events_narrow_filter(narrow) # Note that we pass event_types, not fetch_event_types here, since # that's what controls which future events are sent. queue_id = request_event_queue(user_profile, user_client, apply_markdown, client_gravatar, queue_lifespan_secs, event_types, all_public_streams, narrow=narrow) if queue_id is None: raise JsonableError(_("Could not allocate event queue")) if fetch_event_types is not None: event_types_set = set(fetch_event_types) # type: Optional[Set[str]] elif event_types is not None: event_types_set = set(event_types) else: event_types_set = None # Fill up the UserMessage rows if a soft-deactivated user has returned maybe_catch_up_soft_deactivated_user(user_profile) ret = fetch_initial_state_data(user_profile, event_types_set, queue_id, client_gravatar=client_gravatar, include_subscribers=include_subscribers) # Apply events that came in while we were fetching initial data events = get_user_events(user_profile, queue_id, -1) apply_events(ret, events, user_profile, include_subscribers=include_subscribers, client_gravatar=client_gravatar, fetch_event_types=fetch_event_types) post_process_state(ret) if len(events) > 0: ret['last_event_id'] = events[-1]['id'] else: ret['last_event_id'] = -1 return ret def post_process_state(ret: Dict[str, Any]) -> None: ''' NOTE: Below is an example of post-processing initial state data AFTER we apply events. For large payloads like `unread_msgs`, it's helpful to have an intermediate data structure that is easy to manipulate with O(1)-type operations as we apply events. Then, only at the end, we put it in the form that's more appropriate for client. ''' if 'raw_unread_msgs' in ret: ret['unread_msgs'] = aggregate_unread_data(ret['raw_unread_msgs']) del ret['raw_unread_msgs'] ''' See the note above; the same technique applies below. ''' if 'raw_users'in ret: user_dicts = list(ret['raw_users'].values()) ret['realm_users'] = [d for d in user_dicts if d['is_active']] ret['realm_non_active_users'] = [d for d in user_dicts if not d['is_active']] ''' Be aware that we do intentional aliasing in the below code. We can now safely remove the `is_active` field from all the dicts that got partitioned into the two lists above. We remove the field because it's already implied, and sending it to clients makes clients prone to bugs where they "trust" the field but don't actually update in live updates. It also wastes bandwidth. ''' for d in user_dicts: d.pop('is_active') del ret['raw_users']