[SOLVED] Angular - Only allow text in ng-content

Is it possible to limit the contents between my ng-content tags to just text? How can I do this?

I understand I can use a type-safe input parameter as an alternative, but I would still like to know if this is possible. Thanks!

@Component({
  selector: 'foo',
  template: `
    <div #wrapper>
     <ng-content></ng-content>
    </div>
  `
})
export class FooComponent {
  @ViewChild('wrapper') wrapper;

  ngAfterContentInit() {
    var nodes = this.wrapper.childNodes;
    for (var i = 0; i < nodes.length; i++) {
      if (nodes[i].nodeType != Node.TEXT_NODE) // or if (nodes[i].nodeType != 3)
      throw 'Only text is supported as content
    }
  }
}