svelte – SvelteKit – Inheritance of meta tags

In Svelte and SvelteKit, managing meta tags for SEO and other purposes is essential for optimizing your web application. While SvelteKit provides a built-in way to handle metadata using the $layout special file and the <svelte:head> element, inheritance of meta tags between layouts and components can be a bit different from traditional frameworks.

Here’s a basic overview of how you can manage meta tags in SvelteKit:

1. Layouts in SvelteKit:

SvelteKit uses layouts to wrap your pages and provide a consistent structure. You can use the $layout special file to define a layout. Inside the layout, you can use the <svelte:head> element to specify the metadata.

Example layout file (e.g., src/routes/__layout.svelte):

<!-- src/routes/__layout.svelte -->
<script>
  export let title = "My Website";
  export let description = "Awesome website with SvelteKit";
</script>

<svelte:head>
  <title>{title}</title>
  <meta name="description" content={description} />
  <!-- Add other meta tags as needed -->
</svelte:head>

<main>
  <slot />
</main>

2. Pages in SvelteKit:

Your individual pages can then extend or override these properties by setting them in the respective page components.

Example page file (e.g., src/routes/index.svelte):

<!-- src/routes/index.svelte -->
<script context="module">
  export { preload } from '$layout';
</script>

<script>
  import Layout from '$layout';

  let pageTitle = "Home";
  let pageDescription = "Welcome to my homepage.";

  export let params;
</script>

<Layout title={`${pageTitle} - ${$layout.title}`} description={pageDescription}>
  <!-- Your page content goes here -->
</Layout>

In this example, the index.svelte page sets its own pageTitle and pageDescription, which will be combined with the values from the layout.

3. Dynamic Meta Tags:

If you need to dynamically change meta tags based on data or user interactions, you can use JavaScript to manipulate the <svelte:head> content.

<script>
  import { onMount } from 'svelte';

  let dynamicTitle = "Dynamic Page";
  let dynamicDescription = "This page has dynamic content.";

  onMount(() => {
    // Update meta tags dynamically
    document.title = dynamicTitle;
    document.querySelector('meta[name="description"]').setAttribute('content', dynamicDescription);
  });
</script>

<svelte:head>
  <title>{dynamicTitle}</title>
  <meta name="description" content={dynamicDescription} />
  <!-- Add other meta tags as needed -->
</svelte:head>

Remember that the exact implementation might vary based on your specific requirements and use cases. Always refer to the latest documentation for the most accurate information.