help4bis-com/site/analytics/tracker.js

/* Version: 1.0.0 | Created: 2026-04-08 | Updated: 2026-04-08 */
/* HELP4BIS Analytics Tracker — lightweight, self-hosted, privacy-first */
(function() {
  'use strict';

  var endpoint = '/analytics/track.php';

  function getPagePath() {
    return window.location.pathname || '/';
  }

  function getReferrer() {
    var ref = document.referrer || '';
    // Strip own domain
    if (ref.indexOf(window.location.hostname) !== -1) return '';
    return ref;
  }

  function getScreenSize() {
    return window.screen.width + 'x' + window.screen.height;
  }

  function getUtmParams() {
    var params = {};
    var search = window.location.search;
    if (!search) return params;
    var pairs = search.substring(1).split('&');
    for (var i = 0; i < pairs.length; i++) {
      var kv = pairs[i].split('=');
      var key = decodeURIComponent(kv[0]);
      if (key.indexOf('utm_') === 0) {
        params[key] = decodeURIComponent(kv[1] || '');
      }
    }
    return params;
  }

  function track(eventType, data) {
    var payload = {
      event: eventType,
      page: getPagePath(),
      title: document.title,
      referrer: getReferrer(),
      screen: getScreenSize(),
      language: navigator.language || '',
      utm: getUtmParams(),
      timestamp: new Date().toISOString()
    };

    if (data) {
      for (var key in data) {
        if (data.hasOwnProperty(key)) payload[key] = data[key];
      }
    }

    // Use sendBeacon for reliability, fallback to fetch
    var body = JSON.stringify(payload);
    if (navigator.sendBeacon) {
      navigator.sendBeacon(endpoint, body);
    } else {
      var xhr = new XMLHttpRequest();
      xhr.open('POST', endpoint, true);
      xhr.setRequestHeader('Content-Type', 'application/json');
      xhr.send(body);
    }
  }

  // Track page view on load
  track('pageview');

  // Track time on page (fires on unload)
  var startTime = Date.now();
  window.addEventListener('beforeunload', function() {
    var duration = Math.round((Date.now() - startTime) / 1000);
    if (duration > 1) {
      track('duration', { seconds: duration });
    }
  });

  // Track outbound link clicks
  document.addEventListener('click', function(e) {
    var link = e.target.closest('a');
    if (!link) return;
    var href = link.getAttribute('href') || '';
    // CTA buttons (contact, get started, etc.)
    if (link.classList.contains('btn') || link.classList.contains('cta')) {
      track('cta_click', { href: href, text: (link.textContent || '').trim().substring(0, 80) });
    }
    // Outbound links
    if (href.indexOf('http') === 0 && href.indexOf(window.location.hostname) === -1) {
      track('outbound', { href: href });
    }
    // Phone/email clicks
    if (href.indexOf('tel:') === 0 || href.indexOf('mailto:') === 0) {
      track('contact_click', { href: href });
    }
  });

  // Track form submissions
  document.addEventListener('submit', function(e) {
    var form = e.target;
    track('form_submit', { form_id: form.id || '', form_action: form.action || '' });
  });

  // Track scroll depth (25%, 50%, 75%, 100%)
  var scrollMarks = { 25: false, 50: false, 75: false, 100: false };
  window.addEventListener('scroll', function() {
    var scrollTop = window.pageYOffset || document.documentElement.scrollTop;
    var docHeight = document.documentElement.scrollHeight - document.documentElement.clientHeight;
    if (docHeight <= 0) return;
    var pct = Math.round((scrollTop / docHeight) * 100);
    [25, 50, 75, 100].forEach(function(mark) {
      if (pct >= mark && !scrollMarks[mark]) {
        scrollMarks[mark] = true;
        track('scroll', { depth: mark });
      }
    });
  });
})();