title: Vue.js application in an IFRAME, how to reach parent window
body: <p>I have an SPA Vue.js app based on the <code>webpack</code> template from vuejs-templates and with single-file components.</p>
  
  <p>For legacy reasons, I have to embed this app in a <code>IFRAME</code> in a web page of an existing web site.</p>
  
  <p>From a method within a Vue.js component, I would like to be able to reach the parent window (i.e. the one where the <code>IFRAME</code> is declared), for e.g. opening an alert or setting the value of a DOM Element. </p>
  
  <p>I've tried several classic JavaScript/HTML methods but without success. </p>