How to update the page and query parameters in SvelteKit?

Question

I have a page with a search field. If accessed with a query parameter (e.g. ?word=cat) the page should load with results present and the search field filled. If a search is done the results and the query parameters (browser history) should update.

The only way I found to update query parameters is goto, so my attempt is:

<script context="module">
  export async function load({ page, fetch }) {
    const response = await fetch(`/data.json?${page.query.toString()}`)
    if (response.ok) {
      return {
        props: {
          word: page.query.get('word'),
          body: await response.json()
        }
      }
    }
  }
</script>

<script>
  import { goto } from '$app/navigation'
  import { page } from '$app/stores'

  export let word
  export let body

  function search() {
    $page.query.set('word', word)
    goto(`?${$page.query.toString()}`)
  }
</script>

<main>
  <form on:submit|preventDefault={search}>
    <input bind:value={word}>
  </form>
  <!-- ... -->
</main>

This works but sometimes gets stuck just updating the query parameters and nothing else. For some reason load isn't being called in those cases. I can get it to work reliably by adding await invalidate for the URL before the goto, but now load is always called twice and the search field flips back to the old value shortly.

I just started with Svelte/SvelteKit, so my approach is probably just wrong. Thanks for any help.

Alliterative

try removing the $page.query.set line and simple have goto that should be enough – Guilt

Thanks, I replaced it with a separate URLSearchParams and it works. – Alliterative

Answer 1

I had similar issue triggering load function and I solved it by creating new instance of the URLSearchParams and navigating to these new params.

let query = new URLSearchParams($page.url.searchParams.toString());
    
query.set('word', word);
        
goto(`?${query.toString()}`);

Littman

You don't actually have a create a new URLSearchParams object passing the page.query. the $page.url.searchParams; already returns a urlSearchParams object so you can just assign that to a variable: const urlSearchParams = $page.url.searchParams; – Billon

@Nicholas Mordecai I respectfully disagree. See Anatole Lucet's comment. – Codicil

Answer 2

$page.query is no longer available since it was replaced by $page.url (in @sveltejs/[email protected]).

Now, it is done like this:

$page.url.searchParams.set('word',word); 
goto(`?${$page.url.searchParams.toString()}`);

$page and goto() you can get from:

import { goto } from "$app/navigation";
import { page } from "$app/stores"; 

Braddock

Actually, this will mutate page's internal URLSearchParams which might cause some issues when working with reactive statements. A better way would be to create and mutate a new URLSearchParams from $page.url.searchParams, and then use it in the goto (goto(newSearchParams)). – Daugavpils

Answer 3

You can pass in a URL type in goto function.

const newUrl = new URL($page.url);
newUrl?.searchParams?.set('hello', 'world');
goto(newUrl);

https://kit.svelte.dev/docs/modules#$app-stores-page https://kit.svelte.dev/docs/modules#$app-navigation-goto

Cryohydrate

Answer 4

An even shorter approach:

$page.query.set('word',word); 
goto(`?${$page.query.toString()}`);

Phasia

github.com/sveltejs/kit/issues/2785 – Phasia

Answer 5

To prevent an extra navigation and reload:

$page.query.set('word',word); 
history.replaceState(history.state, '', $page.url);

Bayles

Answer 6

Try this snippet on your page.

Subscribe to query parameter changes with a reactive statement if needed:

I think this is a better approach than navigating to a different page with goto()

http://localhost:5173?tag=travel

<script lang="ts">
  import { page } from "$app/stores";
  // Reactive statement to log a specific query parameter
  $: console.log($page.url.searchParams.get('tag'));
</script>

Historied