title: Reset an ngModel async value if not confirmed
body: <p>I have an input item that upon updating to certain values raises an &quot;are you sure?&quot; type confirmation. If the user says yes, the logic continues, and if not, then the logic does not happen. However, the value still stays at what it was before and does not revert. How can I revert it?</p>
  <p>HTML</p>
  <pre><code>&lt;p-dropdown [options]=&quot;valueOptions&quot; [ngModel]=&quot;storeValue$ | async&quot;
   (ngModelChange)=&quot;checkChange($event)&quot;&gt; &lt;/p-dropdown&gt;
  </code></pre>
  <p>TS</p>
  <pre><code>storeValue$.pipe(tap(value=&gt;this.initialValue = value)); // initialValue is used to compare values in the confirm
  
  checkChange(newValue){
      if(confirm) //psudo-code for if user has accepted change
      {
          // do logic and update value
      } else {
          // do not update
          // ideally set ngModel to this.initialValue
      }
  }
  </code></pre>
  <p>If the ngModel were not bound to an <code>async</code>, then I could just do <code>[ngModel]=&quot;storeValue&quot;</code> and then in the <code>else</code> block do <code>storeValue = this.initialValue</code>. Given that the value <em>does</em> come from an async value, is there a way for me to properly reset it?</p>