Add loadGoogleAnalytics util

packages/analytics-nextjs/src/lib/index.ts

@@ -1,5 +1,6 @@
 export * from './getApiUrl';
 export * from './getTrackingPermissions';
 export * from './isNavigatorTrackingAllowed';
+export * from './loadGoogleAnalytics';
 export * from './noop';
 export * from './stringify';

packages/analytics-nextjs/src/lib/loadGoogleAnalytics.ts

@@ -0,0 +1,47 @@
+function loadTagManager(analyticsId: `GTM-${string}`) {
+    const script = document.createElement('script');
+    script.setAttribute('id', 'google-tag-manager-bootstrap');
+    script.innerHTML = `\
+        (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':
+        new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],
+        j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src=
+        'https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);
+        })(window,document,'script','dataLayer','${analyticsId}');`;
+
+    const noscript = document.createElement('noscript');
+    noscript.innerHTML = `
+            <iframe
+                src="https://www.googletagmanager.com/ns.html?id=${analyticsId}"
+                height="0"
+                width="0"
+                style={{ display: 'none', visibility: 'hidden' }}
+            />
+        `;
+
+    document.head.appendChild(script);
+    document.body.appendChild(noscript);
+}
+
+function loadAnalytics(analyticsId: string) {
+    const gtagScript = document.createElement('script');
+    gtagScript.setAttribute('src', `https://www.googletagmanager.com/gtag/js?id=${analyticsId}`);
+
+    const script = document.createElement('script');
+    script.setAttribute('id', 'google-tag-manager-bootstrap');
+    script.innerHTML = `\
+    window.dataLayer = window.dataLayer || [];
+    function gtag(){dataLayer.push(arguments);}
+    gtag('js', new Date());
+    gtag('config', '${analyticsId}');`;
+
+    document.head.appendChild(gtagScript);
+    document.head.appendChild(script);
+}
+
+export function loadGoogleAnalytics(analyticsId: string) {
+    if (analyticsId.startsWith('GTM-')) {
+        loadTagManager(analyticsId as `GTM-${string}`);
+    } else {
+        loadAnalytics(analyticsId);
+    }
+}