fix/window.gtag is not defined for Next.js-hydration event(#40410) (#…

…40645) Next.js-hydration now triggered after gtag is initialized. Fixed by adding _document.js and appropriate script elements. --- ## Documentation / Examples - [X] Related issues linked using fixes #40410 - [X] Make sure the linting passes by running `pnpm lint` - [X] The "examples guidelines" are followed from [our contributing doc](https://github.com/vercel/next.js/blob/canary/contributing/examples/adding-examples.md) Next.js-hydration now triggered after gtag is initialized.
vercel · Sep 23, 2022 · bebf372 · bebf372
1 parent f19241b
commit bebf372
Showing 1 changed file with 25 additions and 0 deletions.
diff --git a/examples/with-google-analytics/pages/_document.js b/examples/with-google-analytics/pages/_document.js
@@ -0,0 +1,25 @@
+import { Html, Head, Main, NextScript } from 'next/document'
+
+export default function Document() {
+  return (
+    <Html>
+      <Head />
+      <body>
+        <Main />
+        <NextScript />
+
+        {/* Global Site Tag (gtag.js) - Google Analytics */}
+        <script
+          dangerouslySetInnerHTML={{
+            __html: `
+            window.dataLayer = window.dataLayer || [];
+            function gtag(){dataLayer.push(arguments);}
+            gtag('js', new Date());
+
+          `,
+          }}
+        />
+      </body>
+    </Html>
+  )
+}