README

Shows an inline avatar strip of the first 6 repliers in each discussion on the Flarum discussion list. A "+N more" badge opens a paginated modal listing all participants.

How it works

Avatar strip

Participant avatars are served from a dedicated discussion_participant_previews table rather than from a live query against posts. This table stores at most 6 rows per discussion — the first 6 repliers by first-post date, with the original poster excluded (Flarum already shows the OP's avatar natively in the discussion list item).

The discussion list query fetches at most 20 discussions × 6 rows = 120 rows, always bounded regardless of how active discussions are.

Preview rows are written at post-event time (Posted, Hidden, Restored, Deleted) — not at read time. This moves cost to writes (rare) rather than reads (every page load).

Overflow badge

The overflow count (+N more) is derived from participantCount, a native Flarum core attribute maintained by DiscussionMetadataUpdater. The formula is simply participantCount - 7: 7 being the OP avatar plus the 6 avatars in the strip. No extra query is needed and the badge only appears once the strip is full.

Live updates

When a user posts for the first time in a discussion, their avatar is appended to the strip immediately in the UI without a page refresh, provided the strip has fewer than 6 entries. The overflow badge also updates instantly via Flarum's own post-save API response.

Paginated modal

The "+N more" button opens a modal that hits a dedicated endpoint (GET /api/discussions/{id}/participants) returning 20 users per page with minimal attributes (id, username, slug, avatarUrl). No full UserSerializer, no single large payload.

Installation

composer require resofire/discussion-participants
php flarum migrate
php flarum cache:clear

Then enable the extension in the Flarum admin panel.

Existing forums (one-time backfill)

For forums with existing discussions, run the backfill command to populate the preview table:

php flarum participants:populate

Alternatively, use the Recalculate button in the extension's admin page, which processes discussions in chunks of 2,000 and displays per-chunk timing and a total elapsed time.

Upgrading from resofire-v2/discussion-participants

1. Disable the old extension in the admin panel
2. composer remove resofire-v2/discussion-participants
3. composer require resofire/discussion-participants
4. php flarum migrate
5. php flarum cache:clear
6. Enable the new extension in the admin panel

Your existing data (discussion_participant_previews table and participant_count column) is preserved — no recalculation needed.

Memory profile

Requirements

• Flarum 1.8 or later