demo/src/app/components/+popover/demos/events/events.html
<button type="button" class="btn btn-primary"
(onShown)="onShown()" (onHidden)="onHidden()"
popover="Vivamus sagittis lacus vel augue laoreet rutrum faucibus.">
Live demo
</button>
<br>
<br>
<pre class="card card-block card-header mb-3">Event: {{message}}</pre>