Accessing mdx body property in onCreateNode

[absolutejam]

Howdy!

I'm using a custom node type called Doc via. createSchemaCustomization and building the nodes within onCreateType, for any nodes that are of the Mdx type (node.internal.type === "Mdx").

However, I've hit a bit of a road block as I've realised that the body property - which is available on Mdx nodes when querying graphQL - does not exist at this point.

I had the same issue with trying to get gitRemote info, but found that I could resolve this by finding the parentNode and using the gitRemote__NODE property, but in the case of Mdx, I see no similar solution.

Playing around a little more and it seems like I can use:

createNodeField({ node, name: "doc__NODE", value: otherNode.id })

on the Mdx node, then I can query Mdx nodes and navigate via the childDoc property.

This seems like a bit of a hack as I didn't find any docs on this, and I'm not sure if I should be doing this.

Additionally, I wanted to provide the ability to directly query allDoc/doc and get all of the data required, but this method means querying for allMdx/mdx which is less discoverable IMO.

Does anyone have any ideas about this?

[absolutejam]

Finally found something! https://www.gatsbyjs.com/docs/reference/graphql-data-layer/schema-customization/#foreign-key-fields

I'm already using the @link directive in my custom type's schema, but just for defining my own type's shape. I think this might be a way for me to create the fk relationship with an Mdx node; I'll have to play a little more...

[absolutejam]

Oh dear, it looks like I'd set the parent wrong on my custom node all along! (I'd set it to the grandparent).

Simply setting the parent, I can now do parent { body } on my Doc node. It's the simplest things...