# `MishkaCmsCore.Runtime.PageBuilder.Presence`
[🔗](https://github.com/mishka-group/mishka_cms_core/blob/v0.0.1/lib/mishka_cms_core/runtime/page_builder/presence.ex#L5)

Who else is in this editing session — real `Phoenix.Presence` on the session's own PubSub topic.

The prototype drew three hardcoded avatars (JD, AB, CD). That is worse than showing none: it tells
an author their colleagues are watching when nobody is, and it hides the one case that actually
matters — two people editing the same page, where the editor is last-write-wins at the op level.

Tracking costs nothing here because the topic already exists: both LiveViews of a session are
subscribed to it for document updates, so presence rides along.

# `child_spec`

# `display_name`

```elixir
@spec display_name(map() | nil) :: String.t()
```

A display name for a review byline: the local part of the address, `"Someone"` with no user.

Accounts carry no separate name field, so the address is what there is. The domain is dropped
because a comment thread reads better as "ada.love" than as a full address.

# `editors`

```elixir
@spec editors(String.t()) :: [map()]
```

Everyone currently in the session, one entry per person however many tabs they have open.

# `fetch`

# `fetchers_pids`

# `get_by_key`

# `initials`

```elixir
@spec initials(map()) :: String.t()
```

Two letters for an avatar chip, from the local part of an email: `"ada.love@x.com"` gives `"AL"`.

An address is an `Ash.CiString`, not a binary, so it is stringified rather than guarded on —
guarding on `is_binary/1` silently produced "?" for every real user.

# `join`

```elixir
@spec join(String.t(), map() | nil) :: {:ok, binary()} | {:error, term()} | :ignore
```

Announces a user as editing `token`. Safe to call with no user — an anonymous mount tracks nothing.

The entry carries the user's id, initials and whether it is a master, never its email.

# `list`

# `others`

```elixir
@spec others(String.t(), map() | nil) :: [map()]
```

Everyone except `user` — the avatars worth showing, since your own presence is not news.

A master's avatar reads the first letter of `MishkaCmsCore.Accounts.Helper.label(:master)`, "M",
unless `user` is a master too.

# `track`

# `track`

# `untrack`

# `untrack`

# `update`

# `update`

---

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