gatsby-node.js

/**
 * Implement Gatsby's Node APIs in this file.
 *
 * See: https://www.gatsbyjs.org/docs/node-apis/
 */

const { createFilePath } = require(`gatsby-source-filesystem`)
const path = require('path')

exports.onCreateNode = ({ node, getNode, actions }) => {
  const { createNodeField } = actions
  if (
    node.internal.type === `MarkdownRemark` &&
    /.*\/blogs\/.*/.test(node.fileAbsolutePath)
  ) {
    const slug = createFilePath({ node, getNode, basePath: `blogs` })
    createNodeField({
      node,
      name: `slug`,
      value: slug,
    })
  }
}

exports.onCreatePage = async ({ graphql, page, actions }) => {
  const { createPage } = actions
  return new Promise((resolve, reject) => {
    if (page.path.match(/^\/$/)) {
      page.layout = 'landingPage'

      // Update the page.
      createPage(page)
    }

    resolve()
  })
}

exports.createPages = async ({ graphql, actions }) => {
  const { createPage } = actions
  await graphql(`
    {
      allMarkdownRemark(
        filter: { fileAbsolutePath: { regex: "/blogs/.*$/" } }
      ) {
        edges {
          node {
            fields {
              slug
            }
          }
        }
      }
    }
  `).then((result) => {
    result.data.allMarkdownRemark.edges.forEach(({ node }) => {
      createPage({
        path: node.fields.slug,
        component: path.resolve('./src/templates/blog-post.js'),
        context: {
          // Data passed to context is available in page queries as GraphQL variables.
          slug: node.fields.slug,
        },
      })
    })
  })
}