gatsby-node.js

/**
 * Implement Gatsby's Node APIs in this file.
 *
 * See: https://www.gatsbyjs.com/docs/reference/config-files/gatsby-node/
 */

const path = require("path")
const { createFilePath } = require(`gatsby-source-filesystem`)
/**
 * @type {import('gatsby').GatsbyNode['createPages']}
 */
exports.createPages = async ({ graphql, actions }) => {
  const { createPage } = actions
  const result = await graphql(`
    query {
      allMarkdownRemark {
        edges {
          node {
            frontmatter {
              title
            }
            id
          }
        }
      }
    }
  `)

  result.data.allMarkdownRemark.edges.forEach(({ node }) => {
    createPage({
      path: `/blog/${node.id}`,
      component: path.resolve(`./src/templates/blog-post.js`),
      context: {
        id: node.id,
      },
    })
  })
}

exports.onCreateNode = ({ node, getNode, actions }) => {
  const { createNodeField } = actions
  if (node.internal.type === `MarkdownRemark`) {
    const slug = createFilePath({ node, getNode, basePath: `content/blog` })
    createNodeField({
      node,
      name: `slug`,
      value: slug,
    })
  }
}