title: Ionic: How to not stack multiple toast notifications?
body: <p>I got the following Ionic code fragment for displaying alarms / errors in an industrial App:</p>
  
  <pre><code>showError(message: string) {
    let toast = this.toastController.create({
        message: message,
        position: 'top',
        duration: 5000,
        cssClass: 'danger',
        showCloseButton: true
    });
    toast.present();
  }
  </code></pre>
  
  <p>The App triggers the error message every time it detects a connection issues, which will be also roughly on a 5 second timer.</p>
  
  <p>Multiple calls to this method will lead to 2 or more error messages shown on top of each other if the timing of this code is changed. Can I somehow detect that a toast is already being displayed? Also then, the 5000 msec timer would not be necessary and I can just remove the error message again when the connection is re-established.</p>
  
  <p>Thanks and BR Florian</p>