> ## Documentation Index
> Fetch the complete documentation index at: https://doc.lucidworks.com/llms.txt
> Use this file to discover all available pages before exploring further.

# lifecycle:on

export const LwTemplate = ({title = "Key questions to get you started", icon = "sparkles", cta = "Powered by Agent Studio", linkHref = "https://lucidworks.com/demo/?utm_source=docs&utm_medium=referral&utm_campaign=docs_cta_ai"}) => {
  const [isLoaded, setIsLoaded] = useState(false);
  useEffect(() => {
    const timer = setTimeout(() => {
      setIsLoaded(true);
    }, 500);
    return () => clearTimeout(timer);
  }, []);
  return <div className="lw-template-container">
      <Card title={title} icon={icon}>
        {isLoaded && <span dangerouslySetInnerHTML={{
    __html: `<lw-template id="a029c1a9-28be-427e-b0e1-5d918920246a"></lw-template
            >`
  }} />}
        <Link href={linkHref} className="agent-studio-link text-left text-gray-600 gap-2 dark:text-gray-400 text-sm font-medium flex flex-row items-center hover:text-primary dark:hover:text-primary-light group-hover:text-primary group-hover:dark:text-primary-light">Powered by Lucidworks Agent Studio</Link>
      </Card>
    </div>;
};

[localhost link]: http://localhost:3000/docs/4/app-studio/reference/tags/lightning.directive.lifecycleOn

[mintlify link]: https://doc.lucidworks.com/docs/4/app-studio/reference/tags/lightning.directive.lifecycleOn

[old doc.lw link]: https://doc.lucidworks.com/app-studio/4.2/1152

<LwTemplate />

## Description

Shows or hides elements when an event is broadcast

## Usage

as element:

```xml wrap  theme={"dark"}
<lifecycle:on
       event="{string}"
       hide="{boolean}"
       show="{boolean}">
</lifecycle:on>
```

#### Parameters

| Param | Type        | Details                                                      |
| ----- | ----------- | ------------------------------------------------------------ |
| event | **string**  | The name of the event to be listened to                      |
| hide  | **boolean** | If true when the event is heard the elements will be hidden. |
| show  | **boolean** | If true when the event is heard the elements will be shown.  |

## Example

#### Source

```xml wrap  theme={"dark"}
<p>An event called foo will broadcast in 5 seconds.</p>
<lifecycle:delay delay="5000">
    <lifecycle:event event="foo">
        <search:alert style="alertbox-positive">Event foo has been broadcast</search:alert>
    </lifecycle:event>
</lifecycle:delay>
<lifecycle:on event="foo">
    <lifecycle:delay delay="1000">
        <search:alert style="alertbox-positive">Event foo has been heard so I have appeared!</search:alert>
    </lifecycle:delay>
</lifecycle:on>
<lifecycle:on event="foo" hide="true">
    <search:alert style="alertbox-warning">When I hear the event foo I will hide!</search:alert>
</lifecycle:on>
```

#### Result

<img src="https://mintcdn.com/lucidworks/ENcE8K39c0iEpL8J/assets/images/app-studio/as-examples/tags/lifecycleOn.png?fit=max&auto=format&n=ENcE8K39c0iEpL8J&q=85&s=d372a2b2d45876481aa660475bc9a28c" alt="Result" width="1024" height="170" data-path="assets/images/app-studio/as-examples/tags/lifecycleOn.png" />