Fetch Data
In this article, you'll learn how to perform different queries to the Prismic API to get content in your Svelte application.
Before you proceed
First, you'll need a project with SvelteKit and Prismic. If you don't have one yet, start with the Install step.
For client-side fetching, call a Prismic query helper and assign the returned promise directly to a variable (do not wait for the promise to resolve). Then, use Svelte's built-in {#await} block to resolve the promise.
Here's what a basic query looks like:
<script>
import createClient from './../prismicio' // Update the path
import * as prismicH from "@prismicio/helpers"
const client = createClient()
const prismicQuery = client.getFirst()
</script>
<h1>Prismic Svelte App</h1>
{#await prismicQuery}
<p>Loading...</p>
{:then document}
{@html prismicH.asHTML(document.data.example_title)}
{@html prismicH.asHTML(document.data.example_rich_text)}
{:catch error}
<p>Something went wrong:</p>
<pre>{error.message}</pre>
{/await}In SvelteKit, each page can get data from a +page.server.js module. To use data from the Prismic API, we will query the data in +page.server.js, and SvelteKit will pass the data to +page.svelte.
Create the following files:
- src/routes/+page.server.js
- src/routes/+page.server.svelte
- src/routes/[uid]/+page.server.js
- src/routes/[uid]/+page.server.svelte
The root route will serve as the homepage and the [uid] route will query a document dynamically based on the URL.
In the +page.server.js modules, import createClient(), create an instance of the Prismic client, perform a query, and return the response:
- Homepage
- UID Page
import { error } from '@sveltejs/kit'
import createClient from '$lib/prismicio'
export async function load({ fetch, request }) {
const homepageUID = 'homepage' // Update for the UID of your homepage
const client = createClient({ fetch, request })
const document = await client.getByUID('page', homepageUID)
if (document) {
return { document }
}
error(404, 'Not found')
}
import { error } from '@sveltejs/kit'
import createClient from '$lib/prismicio'
export async function load({ fetch, params, request }) {
const { uid } = params
const client = createClient({ fetch, request })
const document = await client.getByUID('page', uid)
if (document) {
return { document }
}
error(404, 'Not found')
}
The document object will be available in the corresponding Svelte file's data prop.
<script>
export let data;
</script>
<pre>{JSON.stringify(data.document, null, 2)}</pre>getByUID(type, uid)
getByUID(type, uid, params)Queries a document from the Prismic repository with a UID and Custom Type. type refers to the API ID of the Custom Type.
const document = await client.getByUID('post', 'my-first-post')getSingle(type)
getSingle(type, params)Queries a singleton document from the Prismic repository for a specific Custom Type. type refers to the API ID of the Custom Type.
For example, here we are querying for the only document of the Custom Type homepage.
const document = await client.getSingle('homepage')getAllByType(type)
getAllByType(type, params)Queries all documents from the Prismic repository for a specific Custom Type. type refers to the API ID of the Custom Type. This method may perform multiple network requests. It returns an array containing all matching documents from the repository.
const documents = await client.getAllByType('article')Further Learning
There are many more methods for querying the API. All of these queries can accept params options to filter, sort, paginate and translate your query response. See them all in the @prismicio/client Technical Reference.
Here are a few common use cases in SvelteKit.
In Prismic, you can create a singleton Custom Type to store site components, like a header, footer, nav menu, or SEO configuration.
To query a singleton, use the getSingle() method with the API ID of the singleton Custom Type.
import { error } from '@sveltejs/kit'
import createClient from '$lib/prismicio'
export async function load({ fetch, request }) {
const client = createClient({ fetch, request })
const menu = await client.getSingle('menu')
if (menu) {
return { menu }
}
error(404, 'Not found')
}
On repeatable documents, we recommend adding a UID field — a unique identifier. Prismic formats each document's UID so it is URL-friendly and unique to its Custom Type.
To query a specific document of a given Custom Type, like a blog post, you can use the getByUID() method. To use getByUID(), pass the UID and the API ID of the Custom Type.
import { error } from '@sveltejs/kit'
import createClient from '$lib/prismicio'
export async function load({ fetch, request }) {
const homepageUID = 'homepage' // Update for the UID of your homepage
const client = createClient({ fetch, request })
const document = await client.getByUID('page', homepageUID)
if (document) {
return { document }
}
error(404, 'Not found')
}
You will likely use getByUID() with a page's URL path to generate a page based on the URL. For instance, at /hello-world, you would want to display the document with the UID hello-world. Rather than hard-coding every page by its UID, in SvelteKit you can use dynamic URL parameters by putting the Svelte component's name in square brackets: src/routes/[uid]/+page.server.js. Then you can access the params and perform a query with it:
import { error } from '@sveltejs/kit'
import createClient from '$lib/prismicio'
export async function load({ fetch, params, request }) {
const { uid } = params
const client = createClient({ fetch, request })
const document = await client.getByUID('page', uid)
if (document) {
return { document }
}
error(404, 'Not found')
}
This will return a document dynamically, based on the URL, so you can template a repeatable document.
There are three ways to get all documents.
- You can query all documents of a certain type with getAllByType() (recommended).
- You can query a paginated list of all documents from your repository, regardless of type, using get(). This will return a paginated response, including the first 100 documents.
- To query an unpaginated list of all documents regardless of type, use dangerouslyGetAll(). Since the payload can be large, this method can cause performance issues, and it is not recommended.
import { error } from '@sveltejs/kit'
import createClient from '$lib/prismicio'
export async function load({ fetch, request }) {
const client = createClient({ fetch, request })
const documents = await client.getAllByType('page')
if (documents) {
return { documents }
}
error(404, 'Not found')
}
Prismic allows you to publish your content in different languages. By default, the API will return content in your master language. To get content in a different language, add an options object with a lang option and a locale code. Here's an example of how to query the document of the type homepage in French (fr-fr).
import { error } from '@sveltejs/kit'
import createClient from '$lib/prismicio'
export async function load({ fetch, request }) {
const client = createClient({ fetch, request })
const homepageUID = 'homepage'
const params = {
lang: 'fr-fr',
}
const document = await client.getByUID('page', homepageUID, params)
if (document) {
return { document }
}
error(404, 'Not found')
}
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