> For the complete documentation index, see [llms.txt](https://developers.newbluefx.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developers.newbluefx.com/api-examples/sample-controllers-tour/04-render-a-preview.md).

# Render a Preview

You might write a controller that needs to show what a title will look like with certain variable settings before going live with it.

The “[snapshot](/captivate-api/all-commands-reference/status-information.md#api-command-getsnapshot)” command does just that. With it, you can set variables and request a preview rendering.

This example shows how to use the snapshot command to preview:

```javascript
scheduler.scheduleCommand(
  'getSnapshot',
  { input: inputName, encode: 1, scaleToFit: 1, width: 800, height: 300, sync: 1 },
  settings.variables,
  (resultString) => {
    console.log(resultString);
  }
);
```

| Parameter            | Description                                                                                                                                    |
| -------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------- |
| `encode`             | tells snapshot to return the png image as a byte-encoded string.                                                                               |
| `width` and `height` | set the size of the returned image.                                                                                                            |
| `scaleToFit`         | tells it to scale the image so it best fits the width and height, while maintaining the correct aspect ratio.                                  |
| `sync`               | tells snapshot to perform the work synchronously and return the data in the callback, otherwise, the data will come in a notification message. |

And then, once you like what you see, safely update the live title using the `scheduleAction` command:

```javascript
scheduler.scheduleAction('update', inputName, '', settings.variables);
```

<figure><img src="https://2284285836-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FXkMvk0MrY3BcyplZ0pf7%2Fuploads%2FuueUPwrwZVx9lF39UwRO%2Fdownload-3.png?alt=media&amp;token=222e2d0b-aef8-40f0-bd84-7ed563436411" alt=""><figcaption></figcaption></figure>


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