title: Angular refresh ngFor with async observable after POST
body: <p>So I am displaying my images from HTTP GET like this</p>
  
  <pre><code>&lt;div *ngFor="let item of (currentGallery$ | async)?.imagesID" class="col-4"&gt;
       &lt;img class="img-fluid" src="url/{{item}}/thumb"&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>but the problem occurs when it comes to upload image to the server and after that display the new image in gallery.</p>
  
  <p>The only solution that I've got so far it is after upload POST, fire the new GET request, but this seems just bad.</p>
  
  <pre><code>this.http.post(url, formImageData).subscribe(data =&gt; {
      this.currentGallery$ = this.http.get&lt;GalleryData&gt;('url');
  }        
  </code></pre>
  
  <p>My post return the uploaded imageID, which I use to display images, so how can I after successful post request put it into array <strong>'imagesID'</strong> in my observable <strong>currentGallery$</strong>, so the ngFor can update itself without second GET after POST? </p>
  
  <p>Or maybe there is some other more proper way?</p>