Angular2 - subscribe to Service variable changes

Question

I have an authentication service that makes the authenticated variable equal to true or false.

checkAuthentication(){
  this._authService.getAuthentication()
           


        

Answer 1

I used a {{ showValue() }} in the component template, and in the .ts file I called the service's variable

showValue() {
   this.authenticated = this._authService.authenticated;
   return "dummy"
} 

Thanks to Angular2's GUI 2-way binding, it works.