gatsby-node.js

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

// try {
//   require.resolve(`babel-plugin-styled-components`)
// } catch (e) {
//   throw new Error(
//     `'babel-plugin-styled-components' is not installed which is needed by plugin 'gatsby-plugin-styled-components'`
//   )
// }

// exports.onCreateBabelConfig = ({ stage, actions }, pluginOptions) => {
//   actions.setBabelPlugin({
//     name: `babel-plugin-styled-components`,
//     stage,
//     options: {
//       ...pluginOptions,
//       ssr: stage === `build-html`
//     }
//   })
// }

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

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

  const blogPost = path.resolve(`./src/templates/blog-post.js`)
  return graphql(
    `
      {
        allMdx(
          filter: { frontmatter: { release: { eq: true } } }
          sort: { fields: [frontmatter___date], order: DESC }
          limit: 1000
        ) {
          edges {
            node {
              fields {
                slug
              }
              frontmatter {
                title
              }
            }
          }
        }
      }
    `
  ).then(result => {
    if (result.errors) {
      throw result.errors
    }

    // Create blog posts pages.
    const posts = result.data.allMdx.edges

    posts.forEach((post, index) => {
      const previous = index === posts.length - 1 ? null : posts[index + 1].node
      const next = index === 0 ? null : posts[index - 1].node

      createPage({
        path: post.node.fields.slug,
        component: blogPost,
        context: {
          slug: post.node.fields.slug,
          previous,
          next
        }
      })
    })

    return null
  })
}

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

  if (node.internal.type === `Mdx`) {
    const value = createFilePath({ node, getNode })
    createNodeField({
      name: `slug`,
      node,
      value
    })
  }
}