Watch a live product demo 👀 See how Sanity powers richer commerce experiences

Sanity and Gatsby - Cannot Read Property '_Type' of Undefined SpanSerializer

10 replies
Last updated: Oct 18, 2020
Hello, I’m trying to make my first website with Sanity and Gatsby but I’m stuck with the importation of Portable Text blocks. Here is my code :
import { graphql } from 'gatsby';
import React from 'react';
import Img from 'gatsby-image';
import BlockContent from '@sanity/block-content-to-react';
import { serializers } from '@sanity/block-content-to-react/lib/targets/dom';

export default function HomePage({ data }) {
  const { home } = data;

  return (
    <>
      <Img fluid={home.image.asset.fluid} alt={home.title} />

      {home.chapo.map(
        (post) =>
          post._rawChildren && (
            <BlockContent
              blocks={post._rawChildren}
              serializers={serializers}
            />
          )
      )}
    </>
  );
}

export const query = graphql`
  query MyQuery {
    home: sanityPage(slug: { current: { eq: "accueil" } }) {
      id
      title
      slug {
        current
      }
      image {
        asset {
          fluid(maxWidth: 1312) {
            ...GatsbySanityImageFluid
          }
        }
      }
      chapo {
        _rawChildren(resolveReferences: { maxDepth: 10 })
      }
      text {
        _rawChildren(resolveReferences: { maxDepth: 10 })
      }
      goals {
        id
        title
        icon {
          asset {
            fixed {
              ...GatsbySanityImageFixed
            }
          }
        }
        list
      }
    }
  }
`;
and I have this error :

TypeError: Cannot read property '_type' of undefined
SpanSerializer
node_modules/@sanity/block-content-to-hyperscript/lib/serializers.js:39
  36 |     mark = _props$node.mark,
  37 |     children = _props$node.children;
  38 | var isPlain = typeof mark === 'string';
> 39 | var markType = isPlain ? mark : mark._type;
  40 | var serializer = props.serializers.marks[markType];
  41 | 
  42 | if (!serializer) {
My block text is just plain text without any embellishment like bold, etc.
I tried many things but without any success.
Thanks for any advice on this.
Oct 18, 2020, 9:44 AM
Hi! Mind sharing the output in your console of
{home.chapo.map(
        (post) => console.log(post) || 
          post._rawChildren && (
            <BlockContent
              blocks={post._rawChildren}
              serializers={serializers}
            />
          )
      )}
?
Oct 18, 2020, 9:52 AM
Yeah, I was wondering about the data structure that comes out of
home.chapo
  🙂
Oct 18, 2020, 9:58 AM
ah ok sorry 😉
Oct 18, 2020, 9:59 AM
Is this better ?
Oct 18, 2020, 10:02 AM
(it’s the
console.log(home.chapo)
)
Oct 18, 2020, 10:04 AM
Ah, now I get it. you're one level too deep. try querying for
_rawChapo
instead and give that to the blockcontent component, so:
<BlockContent blocks={home._rawChapo} serializers={serializers} />

Oct 18, 2020, 10:06 AM
The
children
 are a part of a
_type: 'block'
 object in the Portable Text array.
Oct 18, 2020, 10:06 AM
Ok thanks a lot Knut, I’m gonna try this now
Oct 18, 2020, 10:07 AM
It works ! thank you so much
user Y
!!!
Oct 18, 2020, 10:19 AM
🎉
Oct 18, 2020, 10:19 AM

Sanity– build remarkable experiences at scale

The Sanity Composable Content Cloud is the modern headless CMS that treats content as data to power your digital business. Free to get started, and pay-as-you-go on all plans.

Related answers

Get more help in the community Slack

TopicCategoriesFeaturedRepliesLast Updated
After adding the subtitle and running this code npm run graphql-deploy It does nothingSep 15, 2020
how to limit a reference to just one entry in Studio reference input side versus the default as-many-entries-as-you-fill-in-an-array...Sep 18, 2020
Is it possible to fetch more than one "_type" using GROQ?Nov 2, 2020
I want to add a view with the Structure builder (S.view.component) where I list similar documents based on the title. What...Sep 23, 2020
Is there a structure builder example where the format of each preview for the document list is modified?Feb 3, 2021
I have an array of references to a country schema type but it always just returns NULL values for meJan 30, 2021
Hi, I need help with a query for getting the url of an image asset. Here is what I've been trying, but I only get the _ref...Dec 1, 2020
Sanity UI looks brilliant :smiley: Is something like the current date picker possible at the moment? I’m not sure if anicon...Dec 21, 2020
Hey everyone. I have been coding and may have potentially accidentally deleted something. Does anyone know how to resolve...Dec 26, 2020
Hello everyone and happy new year :raised_hands::skin-tone-2:, I have a problem with outputting Portable Text :disappointed:...Jan 1, 2021

Related contributions

Clean Next.js + Sanity app
- Template

Official(made by Sanity team)

A clean example of Next.js with embedded Sanity ready for recomposition.

Cody Olsen
Go to Clean Next.js + Sanity app

Blog with Built-in Content Editing
- Template

Official(made by Sanity team)

A Sanity-powered blog with built-in content editing and instant previews.

Go to Blog with Built-in Content Editing