gatsby-node.js

const _ = require(`lodash`)
const Promise = require(`bluebird`)
const path = require(`path`)
const slash = require(`slash`)

// Implement the Gatsby API “createPages”. This is
// called after the Gatsby bootstrap is finished so you have
// access to any information necessary to programmatically
// create pages.
// Will create pages for WordPress pages (route : /{slug})
// Will create pages for WordPress posts (route : /post/{slug})
exports.createPages = ({ graphql, actions }) => {
  const { createPage, createRedirect } = actions
  createRedirect({ fromPath: '/', toPath: '/home', redirectInBrowser: true, isPermanent: true })
  return new Promise((resolve, reject) => {
    // The “graphql” function allows us to run arbitrary
    // queries against the local WordPress graphql schema. Think of
    // it like the site has a built-in database constructed
    // from the fetched data that you can run queries against.

    // ==== PAGES (WORDPRESS NATIVE) ====
    graphql(
      `
        {
          allWordpressPage {
            edges {
              node {
                id
                slug
                status
                template
                title
                content
                template
              }
            }
          }
        }
      `
    )
      .then(result => {
        if (result.errors) {
          console.log(result.errors)
          reject(result.errors)
        }

        // Create Page pages.
        const pageTemplate = path.resolve("./src/templates/page.js")
        const portfolioUnderContentTemplate = path.resolve("./src/templates/portfolioUnderContent.js")
        // We want to create a detailed page for each
        // page node. We'll just use the WordPress Slug for the slug.
        // The Page ID is prefixed with 'PAGE_'
        _.each(result.data.allWordpressPage.edges, edge => {
          // Gatsby uses Redux to manage its internal state.
          // Plugins and sites can use functions like "createPage"
          // to interact with Gatsby.

          createPage({
            // Each page is required to have a `path` as well
            // as a template component. The `context` is
            // optional but is often necessary so the template
            // can query data specific to each page.
            path: `/${edge.node.slug}/`,
            component: slash(edge.node.template === 'portfolio_under_content.php' ? portfolioUnderContentTemplate : pageTemplate),
            context: edge.node,
          })
        })
      })
      // ==== END PAGES ====

      // ==== PORTFOLIO ====
      .then(() => {
        graphql(
          `
            {
              allWordpressWpPortfolio{
                edges{
                  node{
                    id
                    title
                    slug
                    excerpt
                    content
                    featured_media{
                      source_url
                    }
                    acf{
                      portfolio_url
                    }
                  }
                }
              }
            }
          `
        ).then(result => {
          if (result.errors) {
            console.log(result.errors)
            reject(result.errors)
          }
          const portfolioTemplate = path.resolve("./src/templates/portfolio.js")
          // We want to create a detailed page for each
          // post node. We'll just use the WordPress Slug for the slug.
          // The Post ID is prefixed with 'POST_'
          _.each(result.data.allWordpressWpPortfolio.edges, edge => {
            createPage({
              path: `/portfolio/${edge.node.slug}/`,
              component: slash(portfolioTemplate),
              context: edge.node,
            })
          })
        })
      })
    // ==== END PORTFOLIO ====
    // ==== BLOG POSTS ====
        .then(() => {
          graphql(`
            {
              allWordpressPost{
                edges{
                  node{
                    excerpt
                    wordpress_id
                    date(formatString: "Do MMM YYYY HH:mm")
                    title
                    content
                    slug
                  }
                }
              }
            }
          `).then(result => {
              if(result.errors){
                  console.log(result.errors)
                  reject(result.errors)
              }

              const posts = result.data.allWordpressPost.edges
              const postsPerPage = 2
              const numberOfPages = Math.ceil(posts.length / postsPerPage)
              const blogPostListTemplate = path.resolve('./src/templates/blogPostList.js')

              Array.from({length: numberOfPages}).forEach((page, index) => {
                  createPage({
                      component: slash(blogPostListTemplate),
                      path: index === 0 ? '/blog' : `/blog/${index + 1}`,
                      context: {
                          posts: posts.slice(index * postsPerPage, (index * postsPerPage) + postsPerPage),
                          numberOfPages,
                          currentPage: index + 1
                      }
                  })
              })

              const pageTemplate = path.resolve("./src/templates/page.js")
              _.each(posts, (post) => {
                  createPage({
                      path: `/post/${post.node.slug}`,
                      component: slash(pageTemplate),
                      context: post.node
                  })
              })

              resolve()
          })
        })
  })
}