Updated the googleAnalytics plugin to take into account page reloads

.codedoc/plugins/ga/index.tsx

@@ -2,22 +2,52 @@ import { StaticRenderer } from '@connectv/sdh';
 import register from 'jsdom-global';
 import { ConfigOverride } from '@codedoc/core';
 
-const renderer = new StaticRenderer();                   // --> create a static renderer
-register();                                              // --> register jdom global so that we can create DOM elements
+const renderer = new StaticRenderer();
+register();
 
+// Documentation
+// Coppied from https://github.com/bender2k14/tyson-williams-blog/blob/2501a6e55ebbf0e559d91ac1494ef2b412739c7d/.codedoc/components/GoogleAnalytics/plugin.tsx#L28
+// Thumbs up to @bender2k14
+// Use gtag.js
+//   not analytics.js https://developers.google.com/analytics/devguides/collection/upgrade
+//   not ga.js        https://developers.google.com/analytics/devguides/collection/gajs/asyncMigrationExamples#basic-page-tracking
+// Default gtag code
+//   https://developers.google.com/analytics/devguides/collection/gtagjs#install_the_global_site_tag
+// Send manual page views for single page applications, which codedoc creates
+//   https://developers.google.com/analytics/devguides/collection/gtagjs/pages#manual_pageviews
+// Default page view arguments
+//   https://developers.google.com/analytics/devguides/collection/gtagjs/pages#default_behavior
+// Test with...
+//     https://support.google.com/analytics/answer/1008080#verify:~:text=Verify%20that%20your%20global%20site%20tag%20is%20working,-To
+//   Real-time view in Google Analytics
+//   Google's Google's Tag Assistant extension for Google Chrome
+//     https://chrome.google.com/webstore/detail/tag-assistant-by-google/kejbdjndbnbjgmefkgdddjlbokphdefk
+// Example use of Google's Tag Assistant
+//   https://www.youtube.com/watch?v=EkNsaBDT8Cc
+// But Google Tag Assistant contains some bugs for single page applications
+//   https://www.analyticsmania.com/post/multiple-installations-of-google-tag-manager-detected/
 
-export function googleAnalytics(gacode: string) {
+export function googleAnalytics(trackingId: string) {
+  let gtagUrl = `https://www.googletagmanager.com/gtag/js?id=${trackingId}`
+  let functionName = 'sendPageViewToGoogle'
+  let functionBody =
+    `gtag('js', new Date());` +
+    `gtag('config', '${trackingId}');`
+  let localCode =
+    'function gtag(){dataLayer.push(arguments);}' +
+    `function ${functionName}(){${functionBody}}` +
+    'window.dataLayer = window.dataLayer || [];' +
+    `window.addEventListener("navigation", ${functionName});` +
+    `${functionName}();`
+  let anonymousFunction =
+    `(function(){${localCode}})();`
   return function(): ConfigOverride {
     return {
       page: {
         scripts: [
-          <script>{`
-          window.ga=window.ga||function(){(ga.q=ga.q||[]).push(arguments)};ga.l=+new Date;
-          ga('create', '${gacode}', 'auto');
-          ga('send', 'pageview');
-          `}</script>,
-          <script async src='https://www.google-analytics.com/analytics.js'/>
-        ],
+          <script async src={gtagUrl}></script>,
+          <script>{anonymousFunction}</script>
+        ]
       }
     }
   };