Instant Google Analytics for SvelteKit, add to +layout.svelte

GoogleAnalytics.svelte

<script>
	import { page } from '$app/stores';
	import { browser } from '$app/environment';
	import { onMount } from 'svelte';

	export let id;

	onMount(() => {
		window.dataLayer = window.dataLayer || [];
		window.gtag = function() { window.dataLayer.push(arguments) }
		window.gtag('js', new Date());
		window.gtag('config', id);
		// console.log('GA init: '+id);
		record($page.url.pathname);
	});

	$: {
		if(browser) {
			if (window.gtag != undefined) {
				record($page.url.pathname);
			}
		}
	}
	
	function record(url) {
		window.gtag('config', id, { 'page_path': url});
		// console.log('GA: '+url);
	}
</script>

<svelte:head>
	<script async src="https://www.googletagmanager.com/gtag/js?id={id}"></script>
</svelte:head>