useObjectPresence

Who else has this record open, live.

Signature

import { useObjectPresence } from '@conduction/nextcloud-vue'

const { others, count, active, depart } =
  useObjectPresence(register, schema, objectUuid, options)

Arguments

Name	Type	Description
register	string | Ref<string>	OpenRegister register slug.
schema	string | Ref<string>	OpenRegister schema slug.
objectUuid	string | Ref<string>	The record being read.
options.enabled	boolean | Ref<boolean> | (() => boolean)	Set false to make the whole thing inert. Default true.

Each address part may be a value, a ref or a getter. A widget host that reuses one instance across records needs the getter form, or presence stays pinned to the first record it saw.

enabled takes the same three forms, and it is re-read rather than sampled once: a consumer whose answer depends on data that arrives after mount — a page deciding from widgets whether a presence row is placed at all — passes a getter, and the beat starts when it flips. A one-shot false would leave the subscription off for good.

Returns

Field	Type	Description
others	ComputedRef<Array<object>>	The other readers, { user, arrivedAt }. The viewer is left out.
count	ComputedRef<number>	How many others.
active	Ref<boolean>	Whether this client is beating.
depart	() => Promise<void>	Leave early, before the route or the tab does.

Usage

<CnPresenceAvatars :present="others" />

setup() {
  const { others, count } = useObjectPresence('dossiq', 'zaak', props.objectId)
  return { others, count }
}

A heartbeat, not a connection

notify_push knows nothing about who is looking at what. A socket can be open while the tab showing this record closed ten minutes ago, and a socket can drop while the reader is still there. So the client says "still here" on a timer, and the server stops believing it after its window. Two missed beats read as gone, which survives a lost socket where connection tracking does not.

The pace is the server's. Its beatSeconds wins whenever it answers with one, because the window is its decision and a client pacing itself to a stale copy drops off the list while its user is still reading.

The list arrives twice, and that is the point

Every beat answers the current list, so this is correct on an instance with no notify_push at all. It simply learns at beat pace. The push is the optimisation: it carries the new list the moment somebody arrives or leaves.

Relying on the push alone would make presence a feature that silently does nothing wherever notify_push is not installed, which is most development instances and some production ones.

Departure is sent twice, also on purpose

Scope disposal covers a route change and an unmount. beforeunload with sendBeacon covers a closed tab, which fires no Vue hook at all. Without the beacon, a closed tab lingers for a whole window on everybody else's screen. The server is idempotent about it.

Render the result with CnPresenceAvatars, or place CnObjectPresenceWidget from a manifest and write no component at all.