var iframe = document.getElementById('my');
var idoc = iframe.contentDocument || iframe.contentWindow.document; // ie compatibility
var text = idoc.getSelection().toString();
key: 'name',
options: [
{ key: 'name', title: 'название', compare: (a, b) => a.localeCompare(b) },
{ key: 'continent', title: 'континент', compare: (a, b) => a.localeCompare(b) },
{ key: 'population', title: 'население', compare: (a, b) => a - b },
{ key: 'population', title: 'население вниз', compare: (a, b) => b - a }
],
<style scoped>
@import 'https://unpkg.com/bootstrap/dist/css/bootstrap.min.css';
@import 'https://unpkg.com/bootstrap-vue@latest/dist/bootstrap-vue.css';
</style>