Upgrade GA tag (analytics.js) to the latest tag (gtag.js)

_includes/google-analytics.html

@@ -5,12 +5,12 @@
   © 2017-2019 Cotes Chung
   MIT License
 -->
+<!-- Global site tag (gtag.js) - Google Analytics -->
+<script async src="https://www.googletagmanager.com/gtag/js?id={{ site.google_analytics.id }}"></script>
 <script>
-  (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
-  (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
-  m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
-  })(window,document,'script','https://www.google-analytics.com/analytics.js','ga');
-
-  ga('create', '{{ site.google_analytics.id }}', 'auto');
-  ga('send', 'pageview');
+  window.dataLayer = window.dataLayer || [];
+  function gtag(){dataLayer.push(arguments);}
+
+  gtag('js', new Date());
+  gtag('config', '{{ site.google_analytics.id }}');
 </script>

_includes/js-selector.html

@@ -35,7 +35,11 @@
 {% endif %}
 
 
-<!-- PWA -->
 {% if jekyll.environment == 'production' %}
+
+  {% include google-analytics.html %}
+
+  <!-- PWA -->
   <script src="{{ '/app.js' | relative_url }}" defer></script>
+
 {% endif %}

_layouts/default.html

@@ -52,12 +52,8 @@
       <i class="fas fa-angle-up"></i>
     </a>
 
-    {% if jekyll.environment == 'production' %}
-      {% include google-analytics.html %}
-    {% endif %}
-
     {% include search-loader.html %}
 
   </body>
 
-</html>
+</html>