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

One fixture event, rendered as a palette button: an event name, its sample
payload verbatim, and the ADR-0005 JSON text a form prefills the payload
field with.

## The `:undefined` asymmetry

`payload` is the fixture value exactly as `StatifierUI.Fixtures.event/2`
returned it - a predicator value, possibly the `:undefined` sentinel that
means "no data". `payload_text` is that value's canonical ADR-0005 JSON,
with one deliberate exception: a `payload` of `:undefined` produces
`payload_text: ""` rather than `~s({"$undefined":true})`.

The reason is the round trip. `StatifierUI.EventInjection.Draft.build/2`
reads a blank payload field as "no data" - the same spelling
`Statifier.Event.external/2` itself defaults to. Emitting the tagged JSON
text for `:undefined` would prefill a form field with text that, if sent
back unedited, still means "no data" but no longer looks blank to a person
editing it; emitting the blank string instead makes the palette's round
trip through the form the identity on the common case. Every other value,
`nil` included, gets its ordinary JSON text (`"null"` for `nil`, `"{}"` for
an empty map). This is the one place in the pane where the encoding and the
form affordance diverge, and it diverges on purpose.

# `t`

```elixir
@type t() :: %StatifierUI.EventInjection.Entry{
  name: String.t(),
  payload: term(),
  payload_text: String.t()
}
```

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