# Type Alias: \_LegacySource

```
type _LegacySource<T> = (handler) => () => void;
```

A simplified source type for legacy API streams

## Type Parameters[#](#type-parameters)

| Type Parameter |
| --- |
| `T` |

## Parameters[#](#parameters)

| Parameter | Type |
| --- | --- |
| `handler` | (`value`) => `void` |

## Returns[#](#returns)

```
(): void;
```

### Returns[#](#returns-1)

`void`

---



[Source](https:/img.ly/docs/cesdk/vue/api/engine/type-aliases/listener)