Creating Pages in Gatsby from different data sources and template

create-pages-blogs.js

/** extracted page creation functionality into smaller functions **/ 

const path = require('path');

function createBlogPostsPages(result, createPage) {

  const blogPostTemplate = path.join(__dirname, `../src/templates/blog-post.js`);
  const blogPosts = result.data.blogs.edges;
  blogPosts.forEach((post, index) => {
    const previous = index === blogPosts.length - 1 ? null : blogPosts[index + 1].node;
    const next = index === 0 ? null : blogPosts[index - 1].node;
    createPage({
      path: post.node.fields.slug,
      component: blogPostTemplate,
      context: {
        slug: post.node.fields.slug,
        previous,
        next,
      },
    });
  });
}

function graphqlForBlogs(graphql, createPage) {
  return graphql(`
      {
       blogs: allMarkdownRemark(
          sort: { fields: [frontmatter___date], order: DESC }
          filter: { frontmatter: { type: { eq: "blog" } } } 
          limit: 1000
        ) {
          edges {
            node {
              fields {
                slug
              }
              frontmatter {
                title
              }
            }
          }
        }
      }
    `).then(result => {
    if (result.errors) {
      throw result.errors;
    }
    // Create blogPosts pages.
    createBlogPostsPages(result, createPage);
  });
}
exports.graphqlForBlogs = graphqlForBlogs;

create-pages-talks.js

/** extracted page creation functionality into smaller functions **/ 

const path = require('path');

function createTalkPostsPages(result, createPage) {
  const talkPostTemplate = path.join(__dirname, "../src/templates/talk-post.js");
  const talkPosts = result.data.talks.edges;
  talkPosts.forEach((post, index) => {
    const previous = index === talkPosts.length - 1 ? null : talkPosts[index + 1].node;
    const next = index === 0 ? null : talkPosts[index - 1].node;
    createPage({
      path: post.node.fields.slug,
      component: talkPostTemplate,
      context: {
        slug: post.node.fields.slug,
        previous,
        next,
      },
    });
  });
}


function graphqlForTalks(graphql, createPage) {
  return graphql(`
      {
        talks: allMarkdownRemark(
          sort: { fields: [frontmatter___date], order: DESC }
          filter: { frontmatter: { type: { eq: "talk" } } } 
          limit: 1000
        ) {
          edges {
            node {
              fields {
                slug
              }
              frontmatter {
                title
              }
            }
          }
        }
      }
    `).then(result => {
    if (result.errors) {
      throw result.errors;
    }
    // Create talkPosts pages.
    createTalkPostsPages(result, createPage);
  });
}
exports.graphqlForTalks = graphqlForTalks;

gatsby-node.js

/** Main file to  create pages, notice how a Promise.all helps in getting  more create page calls */

const { graphqlForTalks } = require("./create-pages/create-pages-talks");

const { graphqlForBlogs } = require("./create-pages/create-pages-blogs");
const { createFilePath } = require(`gatsby-source-filesystem`)


function createIndividualPages(actions, graphql) {
  const { createPage } = actions;

  return Promise.all([
    graphqlForBlogs(graphql, createPage),
    graphqlForTalks(graphql, createPage)
  ])
}

exports.createPages = ({ graphql, actions }) => {
  return createIndividualPages(actions, graphql);
}

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

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