Para quienes tengan problemillas con su layout de Svelte

[Fernando Dodino]

Acá les dejo información que puede ser útil

When using goto in SvelteKit, issues related to layouts often arise from how SvelteKit handles page and layout updates during navigation. Here are common problems and solutions:

1. Layouts Not Re-running Load Functions:

• Problem: 

  Navigating between pages that share a layout might not trigger the layout's load function to re-run, even if data within the layout is expected to change based on the new route. This often happens when only page-specific parameters change, and SvelteKit deems the layout's dependencies unaffected.
• Solution: 

  Manually invalidate the layout's dependencies using invalidate(). If your layout's load function fetches data from an API endpoint, you can invalidate that endpoint's URL to force the layout's load function to re-run.

Código

    <script>
        import { goto, invalidate } from '$app/navigation';

        async function navigateAndInvalidate() {
            await goto('/new-page');
            await invalidate('/api/layout-data'); // Invalidate the API endpoint your layout depends on
        }
    </script>
    <button on:click={navigateAndInvalidate}>Go to new page</button>

2. invalidateAll: true and Layout Update Order:

• Problem: 

  Using goto("...", { invalidateAll: true }) might navigate to the destination page before the parent layout has fully updated, leading to issues if the child page relies on data from the updated layout.
• Solution: 

  Ensure the layout update completes before navigating by chaining invalidateAll() with goto() using a promise:

Código

    <script>
        import { goto, invalidateAll } from '$app/navigation';

        async function navigateSafely() {
            await invalidateAll(); // Invalidate all dependencies first
            await goto('/new-page'); // Then navigate
        }
    </script>
    <button on:click={navigateSafely}>Go to new page</button>

3. Breaking Out of Layout Hierarchy:

• Problem: 

  You may need a specific page to use a different layout or no layout at all, breaking the default hierarchical layout inheritance.
• Solution: 

  SvelteKit provides a mechanism to break out of layouts using a special naming convention for your +page.svelte files.

  • To use only the root layout: +page@.svelte
  • To use a specific parent segment's layout: +p...@segmentName.svelte (e.g., +p...@admin.svelte for a page within /admin that should use /admin/+layout.svelte even if there are deeper layouts).

4. goto Not Triggering Load Functions Predictably:

• Problem: 

  goto might not reliably re-run page load functions if SvelteKit determines that no relevant dependencies have changed, even if URL parameters are different.
• Solution: 

  Explicitly invalidate relevant dependencies (e.g., specific API endpoints or data sources) using invalidate() before or after the goto call to ensure the load function re-runs and fetches fresh data.

By understanding these common scenarios and applying the appropriate invalidate or layout-breaking techniques, you can effectively manage layout behavior when using goto in SvelteKit.