Gatsby Node

gatsby-node.js

const path = require('path')
const { createFilePath } = require('gatsby-source-filesystem')
const { fmImagesToRelative } = require('gatsby-remark-relative-images')
const config = require('./site-config.json')

exports.onCreateNode = ({ node, actions, getNode }) => {
  const { createNodeField } = actions
  fmImagesToRelative(node)

  if (node.internal.type === 'MarkdownRemark') {
    const relativeFilePath = createFilePath({ node, getNode })
    const basename = path.basename(relativeFilePath, '.md')
    createNodeField({
      name: 'name',
      node,
      value: basename,
    })
    createNodeField({
      name: 'slug',
      node,
      value: relativeFilePath,
    })
  }
}

exports.createPages = async ({ actions, graphql }) => {
  const { createPage, createRedirect } = actions

  if (config.redirects.length) {
    config.redirects.forEach(({ from, to, redirectInBrowser }) => {
      createRedirect({
        fromPath: from,
        toPath: to,
        redirectInBrowser: redirectInBrowser,
      })
    })
  }

  return await graphql(`
    {
      allMarkdownRemark(
        sort: { fields: [frontmatter___sort], order: ASC }
        limit: 1000
      ) {
        edges {
          node {
            id
            excerpt(format: PLAIN)
            fileAbsolutePath
            fields {
              name
              slug
            }
            frontmatter {
              title
              sort
              date(formatString: "MMMM DD, YYYY")
              template
            }
          }
        }
      }
    }
  `).then(result => {
    if (result.errors) {
      return Promise.reject(result.errors)
    }

    const pages = result.data.allMarkdownRemark.edges

    return pages.forEach(page => {
      const { node } = page

      createPage({
        path: node.fields.slug,
        component: path.resolve(
          `./src/templates/${node.frontmatter.template}.js`
        ),
        context: {
          slug: node.fields.slug,
        },
      })
    })
  })
}

exports.sourceNodes = ({ actions }) => {
  const { createTypes } = actions
  createTypes(`
    type MarkdownRemarkFrontmatter {
      sort: Int
      date: Date @dateformat
      template: String
    }

    type MarkdownRemark implements Node {
      frontmatter: MarkdownRemarkFrontmatter
    }
  `)
}

exports.onCreateWebpackConfig = ({ getConfig, stage }) => {
  const config = getConfig()
  if (stage.startsWith('develop') && config.resolve) {
    config.resolve.alias = {
      ...config.resolve.alias,
      'react-dom': '@hot-loader/react-dom',
    }
  }
}