### Configure classPrefix in Highlight.js

Source: https://github.com/concretecms/concretecms-core/blob/9.5.x/js/ckeditor/plugins/codesnippet/lib/highlight/CHANGES.md

To suppress the new default behavior of prefixing CSS classes with `hljs-`, initialize Highlight.js with `classPrefix: ''`.

```html
<script type="text/javascript">
  hljs.configure({classPrefix: ''});
  hljs.initHighlightingOnLoad();
</script>
```

--------------------------------

### Include Language Submodes in highlight.js

Source: https://github.com/concretecms/concretecms-core/blob/9.5.x/js/ckeditor/plugins/codesnippet/lib/highlight/CHANGES.md

Demonstrates how to include language submodes directly under 'contains' for auxiliary modes needed in a single place. These modes may not have 'className' and thus won't generate separate spans.

```javascript
contains: [
  'string',
  'number',
  {begin: '\n', end: hljs.IMMEDIATE_RE}
]
```

--------------------------------

### Prevent DOM Clobbering in CKEditor Preview

Source: https://github.com/concretecms/concretecms-core/blob/9.5.x/js/ckeditor/plugins/preview/preview.html

This JavaScript code prevents DOM clobbering by checking if `window.opener._cke_htmlToLoad` is a string. If it is, it opens, writes, and closes a document to load the content safely, then deletes the temporary property.

```javascript
if ( typeof window.opener._cke_htmlToLoad == 'string' ) {
var doc = document;
doc.open();
doc.write( window.opener._cke_htmlToLoad );
doc.close();
delete window.opener._cke_htmlToLoad;
}
```

=== COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.