# `PhoenixKitEntities.Presence`
[🔗](https://github.com/BeamLabEU/phoenix_kit_entities/blob/v0.4.6/lib/phoenix_kit_entities/presence.ex#L1)

Presence tracking for collaborative entity editing.

Uses Phoenix.Presence to track who is currently editing an entity or data record.
The first person to join a topic becomes the "owner" (can edit), and everyone else
becomes "spectators" (read-only mode).

## How It Works

1. When a user opens an edit form, they join a Presence topic (e.g., "entity_edit:5")
2. Presence tracks all connected users with metadata (user info, joined_at timestamp)
3. Users are sorted by joined_at to determine order (FIFO)
4. First user in the sorted list = owner (readonly?: false)
5. All other users = spectators (readonly?: true)
6. When owner leaves, Presence removes them automatically
7. All connected users receive presence_diff event
8. Each user re-evaluates: "Am I first now?"
9. New first user auto-promotes to owner

## Automatic Cleanup

Phoenix.Presence automatically detects when LiveView processes die and removes
them immediately via process monitoring. When a user closes a tab or navigates away:

1. WebSocket disconnects
2. LiveView process terminates
3. Presence automatically cleaned up (via process monitoring)
4. All other users receive presence_diff event instantly

No manual cleanup or timeout configuration needed!

## Topics

- Entity editing: "entity_edit:<entity_uuid>"
- Data editing: "data_edit:<data_uuid>"

# `child_spec`

# `fetch`

# `fetchers_pids`

# `get_by_key`

# `list`

# `track`

# `track`

# `untrack`

# `untrack`

# `update`

# `update`

---

*Consult [api-reference.md](api-reference.md) for complete listing*