next-sanity

Sanity.io toolkit for Next.js.

Features:

Client-side live real-time preview for authenticated users
URL-helper for Sanity’s image pipeline
Rich-text component for Portable Text
GROQ syntax highlighting

Table of contents
Installation
Live real-time preview
- Limits
Optimizing bundle size
Usage
Example: Minimal blog post template
License

Installation

$ npm install next-sanity
// or
$ yarn add next-sanity

Live real-time preview

You can implement real-time client side preview using createPreviewSubscriptionHook. It works by streaming the whole dataset to the browser, which it keeps updated using listeners and Mendoza patches. When it recieves updates, then the query is run against the client-side datastore using groq-js. This only happens if you're logged in and the hook is configured to run, which means you can use this code in production.

You might want to use Vercel’s approach to previews, which is set up with a serverless functions that takes a preview secret, which in turn redirects you to a page with a preview prop set to true.

Limits

The real-time preview isn't optimized and comes with a configured limit of 3000 documents. You can experiment with larger datasets by configuring the hook with documentLimit: <Integer>. Be aware that this might significantly affect the preview performance.

We have plans for optimizations in the roadmap.

Optimizing bundle size

The first version of next-sanity shipped with the picosanity client built-in. This caused some confusion for people who wants not only to pull data from their Sanity.io content lake, but also send patches and mutations via API routes. Since picosanity only supported fetching content, it had a smaller bundle size than the full SDK.

You can leverage Next.js' tree shaking to avoid shipping unnecessary code to the browser. In order to do so, you first need to isolate the client configuration in its own file, and be sure to only use it inside of the data fetching functions (getStaticProps, getServerProps, and getStaticPaths) or in the function that goes into the API routes (/pages/api/<your-serverless-function>.js).

You can follow the approach from the official Next.js preview example:

Make a /lib folder and add config.js, sanity.js, and sanity.server.js to it
In /lib/config.js, add and export the projectId, dataset, apiVersion, and other client configurations
In /lib/sanity.js, import and export the configurated helper functions that you need in the client-side code (like urlFor, usePreviewSubscription, and PortableText)
In /lib/sanity.server.js, create the client(s) you need for interacting with your content in the datafetching functions and in serverless API routes.

Should you want to do queries from the client side but want to avoid bundling the entire @sanity/client, you can of course still install and use picosanity manually.

Usage

It’s practical to set up dedicated files where you import and set up your client etc. Below is a comprehensive example of the different things you can set up.

// lib/config.js
export const config = {
  /**
   * Find your project ID and dataset in `sanity.json` in your studio project.
   * These are considered “public”, but you can use environment variables
   * if you want differ between local dev and production.
   *
   * https://nextjs.org/docs/basic-features/environment-variables
   **/
  dataset: process.env.NEXT_PUBLIC_SANITY_DATASET || 'production',
  projectId: process.env.NEXT_PUBLIC_SANITY_PROJECT_ID,
  apiVersion: '2021-03-25',
  /**
   * Set useCdn to `false` if your application require the freshest possible
   * data always (potentially slightly slower and a bit more expensive).
   * Authenticated request (like preview) will always bypass the CDN
   **/
  useCdn: process.env.NODE_ENV === 'production',
}

// lib/sanity.js
import {
  createImageUrlBuilder,
  createPortableTextComponent,
  createPreviewSubscriptionHook,
  createCurrentUserHook,
} from 'next-sanity'
import {config} from './config'

/**
 * Set up a helper function for generating Image URLs with only the asset reference data in your documents.
 * Read more: https://www.sanity.io/docs/image-url
 **/
export const urlFor = (source) => createImageUrlBuilder(config).image(source)

// Set up the live preview subscription hook
export const usePreviewSubscription = createPreviewSubscriptionHook(config)

// Set up Portable Text serialization
export const PortableText = createPortableTextComponent({
  ...config,
  // Serializers passed to @sanity/block-content-to-react
  // (https://github.com/sanity-io/block-content-to-react)
  serializers: {},
})

// Helper function for using the current logged in user account
export const useCurrentUser = createCurrentUserHook(config)

// lib/sanity.server.js
import {createClient} from 'next-sanity'
import {config} from './config'

// Set up the client for fetching data in the getProps page functions
export const sanityClient = createClient(config)

// Set up a preview client with serverless authentication for drafts
export const previewClient = createClient({
  ...config,
  useCdn: false,
  token: process.env.SANITY_API_TOKEN,
})

// Helper function for easily switching between normal client and preview client
export const getClient = (usePreview) => (usePreview ? previewClient : sanityClient)

Example: Minimal blog post template

A minimal example for a blog post template using the schema from from the Sanity Studio blog example. Includes the real-time preview using the configuration illustrated above:

// pages/posts/[slug].js
import ErrorPage from 'next/error'
import {useRouter} from 'next/router'
import {groq} from 'next-sanity'
import {usePreviewSubscription, urlFor, PortableText} from '../../lib/sanity'
import {getClient} from '../../lib/sanity.server'

const postQuery = groq`
  *[_type == "post" && slug.current == $slug][0] {
    _id,
    title,
    body,
    mainImage,
    categories[]->{
      _id,
      title
    },
    "slug": slug.current
  }
`

export default function Post({data, preview}) {
  const router = useRouter()

  const {data: post} = usePreviewSubscription(postQuery, {
    params: {slug: data.post?.slug},
    initialData: data.post,
    enabled: preview && data.post?.slug,
  })

  if (!router.isFallback && !data.post?.slug) {
    return <ErrorPage statusCode={404} />
  }

  const {title, mainImage, body} = post

  return (
    <article>
      <h2>{title}</h2>
      <figure>
        <img src={urlFor(mainImage).url()} />
      </figure>
      <PortableText blocks={body} />
    </article>
  )
}

export async function getStaticProps({params, preview = false}) {
  const post = await getClient(preview).fetch(postQuery, {
    slug: params.slug,
  })

  return {
    props: {
      preview,
      data: {post},
    },
  }
}

export async function getStaticPaths() {
  const paths = await getClient().fetch(
    groq`*[_type == "post" && defined(slug.current)][].slug.current`
  )

  return {
    paths: paths.map((slug) => ({params: {slug}})),
    fallback: true,
  }
}

License

MIT-licensed. See LICENSE.

aFINKndreas/next-sanity