(function(){ if (!("PerformanceObserver" in window)) return; if (Math.random() > 1) return; var endpoint = "/public/events"; var clsValue = 0; var lcpEntry = null; var inpValue = 0; var sent = {}; function localeFromPath(pathname) { var match = pathname.match(/^\/(en|zh|hi|es|fr|ar|bn|ru|pt|id|et)(?:\/|$)/); return match ? match[1] : "en"; } function rating(name, value) { if (name === "CLS") return value <= 0.1 ? "good" : value <= 0.25 ? "needs-improvement" : "poor"; if (name === "LCP") return value <= 2500 ? "good" : value <= 4000 ? "needs-improvement" : "poor"; if (name === "INP") return value <= 200 ? "good" : value <= 500 ? "needs-improvement" : "poor"; if (name === "FCP") return value <= 1800 ? "good" : value <= 3000 ? "needs-improvement" : "poor"; if (name === "TTFB") return value <= 800 ? "good" : value <= 1800 ? "needs-improvement" : "poor"; return "unknown"; } function enqueue(name, value) { if (!Number.isFinite(value) || value < 0) return; var rounded = name === "CLS" ? Math.round(value * 10000) / 10000 : Math.round(value); var key = name + ":" + rounded; if (sent[key]) return; sent[key] = true; var payload = { event: "web_vital", path: location.pathname, url: location.href, value: name, context: { metric: name, value: rounded, rating: rating(name, rounded), locale: localeFromPath(location.pathname), navigation_type: performance.getEntriesByType("navigation")[0]?.type || "navigate", visibility_state: document.visibilityState, connection: navigator.connection ? { effective_type: navigator.connection.effectiveType || "", save_data: !!navigator.connection.saveData } : {} } }; window.dataLayer = window.dataLayer || []; window.dataLayer.push({ event: "web_vital", web_vital_name: name, web_vital_value: rounded, web_vital_rating: payload.context.rating, page_locale: payload.context.locale }); var body = JSON.stringify(payload); var send = function() { try { if (navigator.sendBeacon) { var blob = new Blob([body], { type: "application/json" }); if (navigator.sendBeacon(endpoint, blob)) return; } fetch(endpoint, { method: "POST", headers: { "Content-Type": "application/json" }, body: body, keepalive: true, credentials: "same-origin" }).catch(function(){}); } catch (e) {} }; if ("requestIdleCallback" in window) { requestIdleCallback(send, { timeout: 3000 }); } else { setTimeout(send, 0); } } function observe(type, callback) { try { var observer = new PerformanceObserver(function(list) { list.getEntries().forEach(callback); }); observer.observe({ type: type, buffered: true }); return observer; } catch (e) { return null; } } observe("paint", function(entry) { if (entry.name === "first-contentful-paint") enqueue("FCP", entry.startTime); }); observe("largest-contentful-paint", function(entry) { lcpEntry = entry; }); observe("layout-shift", function(entry) { if (!entry.hadRecentInput) clsValue += entry.value || 0; }); observe("event", function(entry) { var duration = entry.duration || 0; if (duration > inpValue) inpValue = duration; }); setTimeout(function() { var nav = performance.getEntriesByType("navigation")[0]; if (nav) enqueue("TTFB", nav.responseStart); }, 0); function flushFinalVitals() { if (lcpEntry) enqueue("LCP", lcpEntry.startTime); if (clsValue > 0) enqueue("CLS", clsValue); if (inpValue > 0) enqueue("INP", inpValue); } addEventListener("pagehide", flushFinalVitals, { capture: true }); addEventListener("visibilitychange", function() { if (document.visibilityState === "hidden") flushFinalVitals(); }, { capture: true }); })();

Frequently asked questions

Frequently asked questions