# `StatifierUI.DatamodelExplorer.Entry`
[🔗](https://github.com/riddler/statifier-ui/blob/v0.11.0/lib/statifier_ui/datamodel_explorer/entry.ex#L1)

One node in the datamodel explorer tree (`sui-t36.7`): a `<data>`
declaration, a system variable, a provider function, a fixture scenario
value, or a runtime-only location - the ADR-0003 tiers, plus live mode's
`:runtime` sibling for a location `session.datamodel` never named.

Struct and types only - the way `StatifierUI.EventLog.Round` and
`StatifierUI.EventInjection.Entry` are - because both
`StatifierUI.DatamodelExplorer.Scope` (authoring and live alike) and the
renderer `StatifierUI.DatamodelExplorer.Markdown` share this one shape.

# `t`

```elixir
@type t() :: %StatifierUI.DatamodelExplorer.Entry{
  arity: non_neg_integer() | [non_neg_integer()] | nil,
  changed?: boolean(),
  children: [t()],
  d_index: non_neg_integer() | nil,
  declared_source: String.t() | nil,
  label: String.t(),
  location_source: String.t() | nil,
  name: String.t(),
  shape: StatifierUI.Shape.t(),
  tier: tier(),
  value: term()
}
```

* `value` - always a **decoded** Elixir value, never a `$`-tagged wire
  term. This is the invariant that lets one `StatifierUI.Shape.infer/1`
  pass serve both authoring and live mode.
* `changed?` - live-mode only; defaults to `false`. Authoring mode never
  sets it.
* `arity` - set on `:function` entries only, predicator's
  `non_neg_integer() | [non_neg_integer()]` multi-arity form verbatim.
* `declared_source` - the tier-1 declared expression text, display only.
  Present only when the pane was given the chart source and
  `value_location != location` (`docs/wire-format.md:420-432`).
* `location_source` - `effect.datamodel_change`'s raw author string,
  live mode only, display only.

# `tier`

```elixir
@type tier() :: :data | :system | :function | :scenario | :runtime
```

Which of ADR-0003's tiers this entry belongs to. `:data` and `:runtime`
are both tier 1 - a document `<data id>` declaration and, in live mode
only, a location written at runtime that `session.datamodel`'s snapshot
did not name (an `<invoke idlocation>` or an empty `<finalize>`
auto-assign). `:system` is tier 2a (spec 5.10.1's system variables),
`:function` is tier 2b (predicator provider functions in scope), and
`:scenario` is tier 3 - the one tier that switches source between modes.

---

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