title: From firebase storage download file to iframe
body: <p>With below code, I can not download image to iframe. Instead, it downloaded to local drive.</p>
  
  <p>in JS:</p>
  
  <pre><code>  storageRef.child('images/CopyPerson.jpg').getDownloadURL().then(function(url) {
    var iframe1 = document.getElementById('downloadedCourse');
    iframe1.src = url;
  }).catch(function(error) {
    // Handle any errors
  });
  </code></pre>
  
  <p>in html:</p>
  
  <pre><code>  &lt;iframe id="downloadedCourse" width="800" height="500" src=""&gt;&lt;/iframe&gt;
  </code></pre>
  
  <p>However, if I use img instead of iframe, it works as supposed.  The reason I need use iframe is because I intend to download pdf file. Anyone knows why?</p>