Typeahead for community selection on large instances #126

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opened 2026-08-02 18:18:27 +02:00 by myrmidex · 1 comment

myrmidex commented

2026-08-02 18:18:27 +02:00

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Summary

Channel creation populates a select from GET /api/v3/community/list?type_=Local&limit=50, cached 24h per instance. That works for a self-hosted instance with a handful of communities — belgae.social has 5 — but the endpoint is paginated and a large instance has thousands. The select would be unusable and the cached payload large.

Proposal

Replace the select with a typeahead that queries as the user types, hitting the instance's community search rather than fetching everything up front.

Worth reconsidering the caching strategy at the same time: the 24h per-instance cache suits a small fixed list, but short-lived per-query caching may fit a search-driven UI better.

Priority

Not urgent. This only bites if FFR is pointed at a large public instance; the current approach is adequate for the self-hosted case it was built for.

Notes

Discovered while implementing community selection in #123 "Concurrent publish attempts create duplicate Lemmy posts".
Related: #114 "Validate channel name exists on the instance when creating a channel" — selecting from a list fetched from the instance satisfies that ticket by construction, so #114 may be closable once the select lands. Worth confirming rather than assuming.
No milestone — backlog.

## Summary Channel creation populates a select from `GET /api/v3/community/list?type_=Local&limit=50`, cached 24h per instance. That works for a self-hosted instance with a handful of communities — `belgae.social` has 5 — but the endpoint is paginated and a large instance has thousands. The select would be unusable and the cached payload large. ## Proposal Replace the select with a typeahead that queries as the user types, hitting the instance's community search rather than fetching everything up front. Worth reconsidering the caching strategy at the same time: the 24h per-instance cache suits a small fixed list, but short-lived per-query caching may fit a search-driven UI better. ## Priority Not urgent. This only bites if FFR is pointed at a large public instance; the current approach is adequate for the self-hosted case it was built for. ## Notes - Discovered while implementing community selection in #123 "Concurrent publish attempts create duplicate Lemmy posts". - Related: #114 "Validate channel name exists on the instance when creating a channel" — selecting from a list fetched from the instance satisfies that ticket by construction, so #114 may be closable once the select lands. Worth confirming rather than assuming. - No milestone — backlog.

myrmidex added the

enhancement

label 2026-08-02 18:18:27 +02:00

myrmidex commented

2026-08-06 00:24:31 +02:00

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Confirmed: the select landed; #114 is satisfied by construction.

Committed on release/v1.3.7 as 114 - Select channel communities from the instance instead of typing a slug. The community can no longer be typed, so a non-existent one can't be entered. channel_id now stores the numeric community id (name keeps the slug). #114 was already closed — no state change needed.

Unchanged and still accurate here: the limit=50 cap and the 24h CommunityDirectory cache.

One addition: an unreachable instance now returns a distinct error instead of the misleading "That community does not exist on the selected instance". Worth preserving if the typeahead replaces this fetch path.

**Confirmed: the select landed; #114 is satisfied by construction.** Committed on `release/v1.3.7` as `114 - Select channel communities from the instance instead of typing a slug`. The community can no longer be typed, so a non-existent one can't be entered. `channel_id` now stores the numeric community id (`name` keeps the slug). #114 was already closed — no state change needed. Unchanged and still accurate here: the `limit=50` cap and the 24h `CommunityDirectory` cache. One addition: an unreachable instance now returns a distinct error instead of the misleading "That community does not exist on the selected instance". Worth preserving if the typeahead replaces this fetch path.

myrmidex referenced this issue

2026-08-10 22:59:19 +02:00

Validate PlatformInstance on creation — check it is actually a Lemmy instance #132