> For the complete documentation index, see [llms.txt](https://jsf.gitbook.io/jsf/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://jsf.gitbook.io/jsf/schema/property-options/on-prop-init-actions.md).

# On prop init actions

When prop is initialized, you can do some extra work via `onInit` interface.

| Parameters | Type                  | Description                                                              |
| ---------- | --------------------- | ------------------------------------------------------------------------ |
| event      | `string`              |                                                                          |
| value      | `JsfValueOptionsType` | Check [Value Options](/jsf/interfaces/value-options.md) for description. |

```
onInit?: (
    {
      type: 'set',
      value: JsfValueOptionsInterface
    } |
    {
      type: 'eval',
      $eval: string
    }
    )[];
```