Add Matomo opt-out form

source/privacy.md

@@ -1,8 +1,9 @@
 ---
 title: Privacy Policy
 date: 2023-12-21 18:37:50
+matomooptout: true
 ---
-_Effective date: 24.04.2024_
+_Effective date: 25.04.2024_
 
 ## 1\. Introduction
 
@@ -161,6 +162,16 @@ These third parties have access to your Personal Data only to perform these task
 
 We may use third-party Service Providers to monitor and analyze the use of our Service.
 
+<div id="optout-form">
+  <p> You may choose to prevent this website from aggregating and analyzing the actions you take here. Doing so will protect your privacy, but will also prevent the owner from learning from your actions and creating a better experience for you and other users.</p>
+  <p>To make that choice, please click below to receive an opt-out cookie.</p>
+
+  <p>
+    <input type="checkbox" id="optout" disabled />
+    <label for="optout"><strong id="optoutlabel">You are currently opted out, because Matomo analytics are blocked.</strong></label>
+  </p>
+</div>
+
 ## 15\. CI/CD tools
 
 We may use third-party Service Providers to automate the development process of our Service.

themes/svrjswebsite/layout/layout.ejs

@@ -9,5 +9,8 @@
     <script type="text/javascript" src="/js/fancyheader.js" async=""></script>
     <script type="text/javascript" src="/js/indextabs.js" async=""></script>
     <% } %>
+    <% if (page.matomooptout) { %>
+    <script type="text/javascript" src="/js/matomooptout.js" async=""></script>
+    <% } %>
   </body>
 </html>

themes/svrjswebsite/source/js/matomooptout.js

@@ -0,0 +1,22 @@
+document.addEventListener("DOMContentLoaded", function(event) {
+  function setOptOutText(element) {
+    _paq.push([function() {
+      element.checked = !this.isUserOptedOut();
+      element.disabled = false;
+      (document.querySelector ? document.querySelector('label[for=optout] strong') : document.getElementById('optoutlabel')).innerHTML = this.isUserOptedOut()
+        ? 'You are currently opted out. Click here to opt in.'
+        : 'You are currently opted in. Click here to opt out.';
+    }]);
+  }
+
+  var optOut = document.getElementById("optout");
+  optOut.addEventListener("click", function() {
+    if (this.checked) {
+      _paq.push(['forgetUserOptOut']);
+    } else {
+      _paq.push(['optUserOut']);
+    }
+    setOptOutText(optOut);
+  });
+  setOptOutText(optOut);
+});