Users can add the following html code in designer to add a loading spinner in vbcs.
On button click they can call component ( #loading-dialog ) and select open method.
Now loading dialog is shown, they do some action and after action is completed, they can call component ( #loading-dialog ) and select close method.
Code for loading dialog
<oj-dialog dialog-title="Loading" id="loading-dialog" cancel-behavior="none" class="">
<div slot="body">
<div class="oj-flex oj-sm-justify-content-center">
<oj-progress-circle size="md" value="-1"></oj-progress-circle>
</div>
</div>
<div slot="footer">
</div>
</oj-dialog>View live example in new page – https://khalil232.com/apps/ojet-apps/?ojr=loading-dialog