70 %

Creating MDX Nodes from Raw Strings and Nodes

Raw Strings

If you have a string and you want to create an MDX node from it (for example if you're querying the github API which doesn't give content types), simply create a new node with a mediaType of text/markdown (or any custom mediaType and then add it to gatsby-plugin-mdx's processing options)

const crypto = require("crypto");
exports.sourceNodes = ({
  actions,
  createNodeId,
  createContentDigest
}) => {
  const { createNode } = actions;

  const mdxContent = `---
some: frontmatter
---

# heading

and stuff
`;

  createNode({
    id: `a-node-id`,
    parent: null,
    children: [],
    internal: {
      type: `MyCustomMdxNodesFromString`,
      contentDigest: crypto
        .createHash(`md5`)
        .update(mdxContent)
        .digest(`hex`),
      mediaType: `text/markdown`,
      content: mdxContent,
      description: `My custom MDX nodes`
    }
  });
};

Raw Strings... OR Nodes

and also if you promise to never hold me accountable for what happens you can import the internal function from createMDXNode and create an Mdx node directly. This allows you to skip a bunch of boilerplate and also shows how to attach the Mdx node as a child to your node if you have one.

You can also use a raw string instead of content.

const createMDXNode = require("gatsby-plugin-mdx/utils/create-mdx-node");

exports.onCreateNode = async ({
  node,
  actions,
  createNodeId,
  loadNodeContent
}) => {
  const { createNode, createParentChildLink } = actions;
  // do any checks for which content you want to transform here
  if (node.internal.type === "File") {
    const content = await loadNodeContent(node);
    const mdxNode = await createMDXNode({
      id: createNodeId(`${node.id} >>> Mdx`),
      node,
      content
    });
    createNode(mdxNode);
    createParentChildLink({ parent: node, child: mdxNode });
  }
};