## Focus event

Triggered when the `Element` gains focus.

**Syntax:** `element.on(...)`

- `event` ('focus') **required**
  The name of the event.
In this case, `focus`.

- `handler` (function) **required**
  `handler(event) => void` is a **callback function** that you provide that will be called when the event is fired.

### Handle an Element focus event

```js
element.on('focus', function(event) {
  // Handle focus event
});
```

```es_next
element.on('focus', (event) => {
  // Handle focus event
});
```