title: ionic 3 publish app as PWA (Progressive Web App)
body: <p>I want to publish my app as PWA so what i did is</p>
  
  <p>insert this script to index.html</p>
  
  <pre><code>&lt;!--script&gt;
      if ('serviceWorker' in navigator) {
        navigator.serviceWorker.register('service-worker.js')
          .then(() =&gt; console.log('service worker installed'))
          .catch(err =&gt; console.log('Error', err));
      }
  &lt;/script--&gt;
  </code></pre>
  
  <p>then install</p>
  
  <pre><code>npm run ionic:build --prod 
  </code></pre>
  
  <p>it looks like it deploy it but my questions are:</p>
  
  <ol>
  <li>what files I need to upload to host for publish the app as PWA?</li>
  <li><p>why when I change something in the app and run ionic serve nothing changed and it changed only in the index.html of the WWW folder? why?(because now it's PWA??)</p></li>
  <li><p>when I open www folder and I run open index.html when i press on button that open alert dialog it not open that. why?</p></li>
  <li>when I run the command? only in the end of development?</li>
  </ol>