app/javascript/mastodon/reducers/timelines.js
import { Map as ImmutableMap, List as ImmutableList, OrderedSet as ImmutableOrderedSet, fromJS } from 'immutable';
import {
blockAccountSuccess,
muteAccountSuccess,
unfollowAccountSuccess
} from '../actions/accounts';
import {
TIMELINE_UPDATE,
TIMELINE_DELETE,
TIMELINE_CLEAR,
TIMELINE_EXPAND_SUCCESS,
TIMELINE_EXPAND_REQUEST,
TIMELINE_EXPAND_FAIL,
TIMELINE_SCROLL_TOP,
TIMELINE_CONNECT,
TIMELINE_DISCONNECT,
TIMELINE_LOAD_PENDING,
TIMELINE_MARK_AS_PARTIAL,
TIMELINE_INSERT,
TIMELINE_GAP,
TIMELINE_SUGGESTIONS,
} from '../actions/timelines';
import { compareId } from '../compare_id';
const initialState = ImmutableMap();
const initialTimeline = ImmutableMap({
unread: 0,
online: false,
top: true,
isLoading: false,
hasMore: true,
pendingItems: ImmutableList(),
items: ImmutableList(),
});
const isPlaceholder = value => value === TIMELINE_GAP || value === TIMELINE_SUGGESTIONS;
const expandNormalizedTimeline = (state, timeline, statuses, next, isPartial, isLoadingRecent, usePendingItems) => {
// This method is pretty tricky because:
// - existing items in the timeline might be out of order
// - the existing timeline may have gaps, most often explicitly noted with a `null` item
// - ideally, we don't want it to reorder existing items of the timeline
// - `statuses` may include items that are already included in the timeline
// - this function can be called either to fill in a gap, or load newer items
return state.update(timeline, initialTimeline, map => map.withMutations(mMap => {
mMap.set('isLoading', false);
mMap.set('isPartial', isPartial);
if (!next && !isLoadingRecent) mMap.set('hasMore', false);
if (timeline.endsWith(':pinned')) {
mMap.set('items', statuses.map(status => status.get('id')));
} else if (!statuses.isEmpty()) {
usePendingItems = isLoadingRecent && (usePendingItems || !mMap.get('pendingItems').isEmpty());
mMap.update(usePendingItems ? 'pendingItems' : 'items', ImmutableList(), oldIds => {
const newIds = statuses.map(status => status.get('id'));
// Now this gets tricky, as we don't necessarily know for sure where the gap to fill is
// and some items in the timeline may not be properly ordered.
// However, we know that `newIds.last()` is the oldest item that was requested and that
// there is no “hole” between `newIds.last()` and `newIds.first()`.
// First, find the furthest (if properly sorted, oldest) item in the timeline that is
// newer than the oldest fetched one, as it's most likely that it delimits the gap.
// Start the gap *after* that item.
const lastIndex = oldIds.findLastIndex(id => !isPlaceholder(id) && compareId(id, newIds.last()) >= 0) + 1;
// Then, try to find the furthest (if properly sorted, oldest) item in the timeline that
// is newer than the most recent fetched one, as it delimits a section comprised of only
// items older or within `newIds` (or that were deleted from the server, so should be removed
// anyway).
// Stop the gap *after* that item.
const firstIndex = oldIds.take(lastIndex).findLastIndex(id => !isPlaceholder(id) && compareId(id, newIds.first()) > 0) + 1;
let insertedIds = ImmutableOrderedSet(newIds).withMutations(insertedIds => {
// It is possible, though unlikely, that the slice we are replacing contains items older
// than the elements we got from the API. Get them and add them back at the back of the
// slice.
const olderIds = oldIds.slice(firstIndex, lastIndex).filter(id => !isPlaceholder(id) && compareId(id, newIds.last()) < 0);
insertedIds.union(olderIds);
// Make sure we aren't inserting duplicates
insertedIds.subtract(oldIds.take(firstIndex), oldIds.skip(lastIndex));
}).toList();
// Finally, insert a gap marker if the data is marked as partial by the server
if (isPartial && (firstIndex === 0 || oldIds.get(firstIndex - 1) !== TIMELINE_GAP)) {
insertedIds = insertedIds.unshift(TIMELINE_GAP);
}
return oldIds.take(firstIndex).concat(
insertedIds,
oldIds.skip(lastIndex),
);
});
}
}));
};
const updateTimeline = (state, timeline, status, usePendingItems) => {
const top = state.getIn([timeline, 'top']);
if (usePendingItems || !state.getIn([timeline, 'pendingItems']).isEmpty()) {
if (state.getIn([timeline, 'pendingItems'], ImmutableList()).includes(status.get('id')) || state.getIn([timeline, 'items'], ImmutableList()).includes(status.get('id'))) {
return state;
}
return state.update(timeline, initialTimeline, map => map.update('pendingItems', list => list.unshift(status.get('id'))).update('unread', unread => unread + 1));
}
const ids = state.getIn([timeline, 'items'], ImmutableList());
const includesId = ids.includes(status.get('id'));
const unread = state.getIn([timeline, 'unread'], 0);
if (includesId) {
return state;
}
let newIds = ids;
return state.update(timeline, initialTimeline, map => map.withMutations(mMap => {
if (!top) mMap.set('unread', unread + 1);
if (top && ids.size > 40) newIds = newIds.take(20);
mMap.set('items', newIds.unshift(status.get('id')));
}));
};
const deleteStatus = (state, id, references, exclude_account = null) => {
state.keySeq().forEach(timeline => {
if (exclude_account === null || (timeline !== `account:${exclude_account}` && !timeline.startsWith(`account:${exclude_account}:`))) {
const helper = list => list.filterNot(item => item === id);
state = state.updateIn([timeline, 'items'], helper).updateIn([timeline, 'pendingItems'], helper);
}
});
// Remove reblogs of deleted status
references.forEach(ref => {
state = deleteStatus(state, ref, [], exclude_account);
});
return state;
};
const clearTimeline = (state, timeline) => {
return state.set(timeline, initialTimeline);
};
const filterTimelines = (state, relationship, statuses) => {
let references;
statuses.forEach(status => {
if (status.get('account') !== relationship.id) {
return;
}
references = statuses.filter(item => item.get('reblog') === status.get('id')).map(item => item.get('id'));
state = deleteStatus(state, status.get('id'), references, relationship.id);
});
return state;
};
const filterTimeline = (timeline, state, relationship, statuses) => {
const helper = list => list.filterNot(statusId => statuses.getIn([statusId, 'account']) === relationship.id);
return state.updateIn([timeline, 'items'], ImmutableList(), helper).updateIn([timeline, 'pendingItems'], ImmutableList(), helper);
};
const updateTop = (state, timeline, top) => {
return state.update(timeline, initialTimeline, map => map.withMutations(mMap => {
if (top) mMap.set('unread', mMap.get('pendingItems').size);
mMap.set('top', top);
}));
};
const reconnectTimeline = (state, usePendingItems) => {
if (state.get('online')) {
return state;
}
return state.withMutations(mMap => {
mMap.update(usePendingItems ? 'pendingItems' : 'items', items => items.first() ? items.unshift(TIMELINE_GAP) : items);
mMap.set('online', true);
});
};
export default function timelines(state = initialState, action) {
switch(action.type) {
case TIMELINE_LOAD_PENDING:
return state.update(action.timeline, initialTimeline, map =>
map.update('items', list => map.get('pendingItems').concat(list.take(40))).set('pendingItems', ImmutableList()).set('unread', 0));
case TIMELINE_EXPAND_REQUEST:
return state.update(action.timeline, initialTimeline, map => map.set('isLoading', true));
case TIMELINE_EXPAND_FAIL:
return state.update(action.timeline, initialTimeline, map => map.set('isLoading', false));
case TIMELINE_EXPAND_SUCCESS:
return expandNormalizedTimeline(state, action.timeline, fromJS(action.statuses), action.next, action.partial, action.isLoadingRecent, action.usePendingItems);
case TIMELINE_UPDATE:
return updateTimeline(state, action.timeline, fromJS(action.status), action.usePendingItems);
case TIMELINE_DELETE:
return deleteStatus(state, action.id, action.references, action.reblogOf);
case TIMELINE_CLEAR:
return clearTimeline(state, action.timeline);
case blockAccountSuccess.type:
case muteAccountSuccess.type:
return filterTimelines(state, action.payload.relationship, action.payload.statuses);
case unfollowAccountSuccess.type:
return filterTimeline('home', state, action.payload.relationship, action.payload.statuses);
case TIMELINE_SCROLL_TOP:
return updateTop(state, action.timeline, action.top);
case TIMELINE_CONNECT:
return state.update(action.timeline, initialTimeline, map => reconnectTimeline(map, action.usePendingItems));
case TIMELINE_DISCONNECT:
return state.update(
action.timeline,
initialTimeline,
map => map.set('online', false).update(action.usePendingItems ? 'pendingItems' : 'items', items => items.first() ? items.unshift(TIMELINE_GAP) : items),
);
case TIMELINE_MARK_AS_PARTIAL:
return state.update(
action.timeline,
initialTimeline,
map => map.set('isPartial', true).set('items', ImmutableList()).set('pendingItems', ImmutableList()).set('unread', 0),
);
case TIMELINE_INSERT:
return state.update(
action.timeline,
initialTimeline,
map => map.update('items', ImmutableList(), list => {
if (!list.includes(action.key)) {
return list.insert(action.index, action.key);
}
return list;
})
);
default:
return state;
}
}