# `Drafter.EventResult`
[🔗](https://github.com/jaman/drafter/blob/main/lib/drafter/event/event_result.ex#L1)

Normalises what a widget's `handle_event/2` returned into the triple the router uses.

`parse/2` maps every accepted return shape onto `{new_state, actions, mode}`, or
the bare atom `:not_handled`. The modes are:

  * `:stop` — handled; the event does not travel to the parent
  * `:bubble` — handled, and the event still travels to the parent
  * `:not_handled` — the widget did not act on the event

## Examples

    iex> Drafter.EventResult.parse({:ok, %{count: 1}}, %{count: 0})
    {%{count: 1}, [], :stop}

# `mode`

```elixir
@type mode() :: :stop | :bubble | :not_handled
```

# `t`

```elixir
@type t() :: {term(), list(), mode()} | :not_handled
```

# `parse`

```elixir
@spec parse(term(), term()) :: t()
```

Normalise a widget handler's return value.

Accepted shapes, where `state` is the widget's new state and `actions` a list:

  * `{:ok, state, actions}` and `{:ok, state}` → `:stop`
  * `{:bubble, state, actions}` and `{:bubble, state}` → `:bubble`
  * `{:noreply, _}` → `:not_handled`
  * a bare action `{:pop, _}`, `{:push, _, _}`, `{:replace, _, _}` or
    `{:app_callback, _, _}` → `{fallback, [action], :stop}`

`fallback` is the state to keep when the handler returned an action instead of a
state — normally the state the widget had before the call. Anything else returns
`:not_handled` and `fallback` is unused.

## Examples

    iex> Drafter.EventResult.parse({:ok, :new, [:act]}, :old)
    {:new, [:act], :stop}

    iex> Drafter.EventResult.parse({:ok, :new}, :old)
    {:new, [], :stop}

    iex> Drafter.EventResult.parse({:bubble, :new}, :old)
    {:new, [], :bubble}

    iex> Drafter.EventResult.parse({:noreply, :new}, :old)
    :not_handled

    iex> Drafter.EventResult.parse({:pop, :result}, :old)
    {:old, [{:pop, :result}], :stop}

    iex> Drafter.EventResult.parse({:app_callback, :saved, 1}, :old)
    {:old, [{:app_callback, :saved, 1}], :stop}

    iex> Drafter.EventResult.parse(:something_else, :old)
    :not_handled

---

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