UX/DSGVO: Consent-Optionen und Top-Link ergänzt

assets/js/main.js

@@ -5,19 +5,165 @@ document.addEventListener("DOMContentLoaded", () => {
   }
 
   const navbar = document.getElementById("mainNav");
-  if (!navbar) {
+  if (navbar) {
+    const collapseElement = navbar.querySelector(".navbar-collapse");
+    const navLinks = navbar.querySelectorAll(".nav-link");
+    const collapse = collapseElement ? bootstrap.Collapse.getOrCreateInstance(collapseElement, { toggle: false }) : null;
+
+    navLinks.forEach((link) => {
+      link.addEventListener("click", () => {
+        if (window.innerWidth < 992 && collapse) {
+          collapse.hide();
+        }
+      });
+    });
+  }
+
+  setupConsentManager();
+  setupTopLink();
+});
+
+const consentStorageKey = "paConsentPreferencesV1";
+
+function getStoredConsent() {
+  try {
+    const raw = localStorage.getItem(consentStorageKey);
+    return raw ? JSON.parse(raw) : null;
+  } catch {
+    return null;
+  }
+}
+
+function storeConsent(consent) {
+  localStorage.setItem(consentStorageKey, JSON.stringify(consent));
+}
+
+function loadMatomo() {
+  if (window.__matomoLoaded) {
     return;
   }
 
-  const collapseElement = navbar.querySelector(".navbar-collapse");
-  const navLinks = navbar.querySelectorAll(".nav-link");
-  const collapse = collapseElement ? bootstrap.Collapse.getOrCreateInstance(collapseElement, { toggle: false }) : null;
+  window.__matomoLoaded = true;
+  const _paq = (window._paq = window._paq || []);
+  _paq.push(["trackPageView"]);
+  _paq.push(["enableLinkTracking"]);
 
-  navLinks.forEach((link) => {
-    link.addEventListener("click", () => {
-      if (window.innerWidth < 992 && collapse) {
-        collapse.hide();
-      }
-    });
+  const u = "https://piwik.webfarben.net/";
+  _paq.push(["setTrackerUrl", u + "matomo.php"]);
+  _paq.push(["setSiteId", "5"]);
+
+  const d = document;
+  const g = d.createElement("script");
+  const s = d.getElementsByTagName("script")[0];
+  g.async = true;
+  g.src = u + "matomo.js";
+  s.parentNode.insertBefore(g, s);
+}
+
+function setupConsentManager() {
+  const existingConsent = getStoredConsent();
+  if (existingConsent?.analytics) {
+    loadMatomo();
+  }
+
+  injectConsentUi();
+
+  if (!existingConsent) {
+    openConsentBanner();
+  }
+}
+
+function injectConsentUi() {
+  const panel = document.createElement("aside");
+  panel.id = "consentPanel";
+  panel.className = "consent-panel";
+  panel.innerHTML =
+    '<h2>Datenschutz-Einstellungen</h2>' +
+    '<p>Wir verwenden Matomo zur anonymisierten Reichweitenmessung. Sie entscheiden, ob Statistik-Cookies gesetzt werden.</p>' +
+    '<div class="consent-options">' +
+    '<label class="consent-option">' +
+    '<input id="consentAnalytics" type="checkbox" />' +
+    '<span>Statistik (Matomo) erlauben</span>' +
+    "</label>" +
+    "</div>" +
+    '<div class="consent-actions">' +
+    '<button type="button" id="consentAcceptAll" class="btn btn-brand btn-sm">Alle akzeptieren</button>' +
+    '<button type="button" id="consentEssential" class="btn btn-outline-secondary btn-sm">Nur notwendig</button>' +
+    '<button type="button" id="consentSave" class="btn btn-outline-light btn-sm">Auswahl speichern</button>' +
+    "</div>";
+
+  const trigger = document.createElement("button");
+  trigger.type = "button";
+  trigger.id = "consentOpenButton";
+  trigger.className = "consent-open-button";
+  trigger.textContent = "Cookie-Einstellungen";
+
+  document.body.append(panel, trigger);
+
+  const analyticsInput = document.getElementById("consentAnalytics");
+  const consent = getStoredConsent();
+  if (consent?.analytics && analyticsInput) {
+    analyticsInput.checked = true;
+  }
+
+  trigger.addEventListener("click", openConsentBanner);
+
+  document.getElementById("consentAcceptAll")?.addEventListener("click", () => {
+    saveConsent({ analytics: true });
+    if (analyticsInput) {
+      analyticsInput.checked = true;
+    }
   });
-});
+
+  document.getElementById("consentEssential")?.addEventListener("click", () => {
+    saveConsent({ analytics: false });
+    if (analyticsInput) {
+      analyticsInput.checked = false;
+    }
+  });
+
+  document.getElementById("consentSave")?.addEventListener("click", () => {
+    saveConsent({ analytics: Boolean(analyticsInput?.checked) });
+  });
+}
+
+function openConsentBanner() {
+  document.getElementById("consentPanel")?.classList.add("is-visible");
+}
+
+function closeConsentBanner() {
+  document.getElementById("consentPanel")?.classList.remove("is-visible");
+}
+
+function saveConsent(consent) {
+  storeConsent(consent);
+  if (consent.analytics) {
+    loadMatomo();
+  }
+  closeConsentBanner();
+}
+
+function setupTopLink() {
+  const topLink = document.createElement("button");
+  topLink.type = "button";
+  topLink.className = "top-link-button";
+  topLink.setAttribute("aria-label", "Nach oben");
+  topLink.textContent = "Nach oben";
+
+  topLink.addEventListener("click", () => {
+    window.scrollTo({ top: 0, behavior: "smooth" });
+  });
+
+  document.body.append(topLink);
+
+  const toggleTopLink = () => {
+    if (window.scrollY > 320) {
+      topLink.classList.add("is-visible");
+    } else {
+      topLink.classList.remove("is-visible");
+    }
+  };
+
+  toggleTopLink();
+  window.addEventListener("scroll", toggleTopLink, { passive: true });
+}