title: C# HttpPost Progress updates to Angular 6
body: <p>In my Angular 6 application i have a progress bar that should show the rendering and downloading progress of a PDF file in percent. 
  My Post call looks like the following:</p>
  
  <pre class="lang-js prettyprint-override"><code>renderReport(renderObjectId: number): Observable&lt;HttpEvent&lt;Blob&gt;&gt; {
      return this.httpService.post('/render/report/' + renderObjectId, {
          observe: 'events',
          responseType: 'blob'
      });
  }
  </code></pre>
  
  <p>The corresponding method in the backend looks like this</p>
  
  <pre class="lang-cs prettyprint-override"><code>[HttpPost]
  [Route("report/{renderReportId}")]
  [ResponseType(typeof(HttpResponseMessage))]
  public HttpResponseMessage PrintReport(int renderReportId)
  {
      var man = new RenderingManager();
      MemoryStream pdfFileStream = man.RenderReport(renderReportId);
      return CreatePdfDownload(pdfFileStream);
  }
  </code></pre>
  
  <p>The <code>RenderReport()</code> method takes a while because there is xml written, validated etc.
  What i want to achieve is that in the frontend i can subscribe to the result of the <code>renderReport(renderObjectId: number)</code> and get multiple updates from the Backend like: "currently in step 5 of 12 in RenderReport()".</p>
  
  <p>Is that somehow possible? Maybe manually returning a self-defined status after each method called in <code>RenderReport</code>?</p>