Gatsby Wordpress ACF won't exposed fields if not used

[amirmeimari]

This is so simple yet so frustrating!
I created a custom field in ACF and try to fetch data using gatsby-source-wordpress plugin in my blog posts.
If I don't use that custom field in any of my blog posts(in Wordpress admin panel when i try to publish or edit a post), gatsby graphql schema won't create that filed and I cannot query to get data. is there any way to edit graphql schema that comes from this plugin?
I want to be able to query this field if exists, if not it should return null. but field should be there in the schema in the first place otherwise build would fail!

My query:

  query {
      allWordpressPost {
        edges {
          node {
            slug
            content
            acf { # because myCustomField is not avaible so this is not available too
              myCustomField # This is not available to query!
            }
          }
        }
      }
    }

The error I get:

There was an error in your GraphQL query:

Cannot query field "myCustomField " on type "wordpress__POSTAcf".

If you don't expect "myCustomField" to exist on the type "wordpress__POSTAcf" it is most likely a typo.

[LekoArts]

Hi, thanks for the issue!

You'll want to use Schema Customization to explicitly define the myCustomField - when it doesn't exist it'll return null.

I'd also encourage you to try out https://github.com/gatsbyjs/gatsby-source-wordpress-experimental as it'll also fix your issue with that, see: https://github.com/gatsbyjs/gatsby-source-wordpress-experimental/blob/master/docs/problems-with-v3.md

This means Gatsby needed to use inference to automatically build GraphQL types for the data that was returned from WP. The big issue with this is: if all data of a type is removed from WP, your Gatsby site's GraphQL queries will break because no data means Gatsby can no longer can infer the data structure. This led to a lot of odd and counterintuitive issues and a poor developer/content creator experience.

[amirmeimari]

Thanks, I'm currently trying v4 but I faced some issues. Overall very good update 👍