gatsby-node.js

import path from 'path';
import fetch from 'isomorphic-fetch';

const turnPizzasIntoPages = async ({ graphql, actions }) => {
  // 1. get template for this page
  const pizzaTemplate = path.resolve('./src/templates/Pizza.js');

  // 2. query all pizzas
  const { data } = await graphql(`
    query {
      pizzas: allSanityPizza {
        nodes {
          name
          slug {
            current
          }
        }
      }
    }
  `);

  // 3. loop over each pizza, create page for each
  data.pizzas.nodes.forEach((pizza) => {
    actions.createPage({
      path: `pizza/${pizza.slug.current}`,
      component: pizzaTemplate,
      context: {
        slug: pizza.slug.current,
      },
    });
  });
};

const turnToppingsIntoPages = async ({ graphql, actions }) => {
  // 1. get template for this page
  const toppingTemplate = path.resolve('./src/pages/pizzas.js');

  // 2. query all toppings
  const { data } = await graphql(`
    query {
      toppings: allSanityTopping {
        nodes {
          id
          name
        }
      }
    }
  `);

  // 3. loop over each pizza, create page for each
  data.toppings.nodes.forEach((topping) => {
    actions.createPage({
      path: `topping/${topping.name}`,
      component: toppingTemplate,
      context: {
        topping: topping.name,
      },
    });
  });
};

const fetchBeersAndTurnIntoNodes = async ({
  actions,
  createNodeId,
  createContentDigest,
}) => {
  // 1. Fetch a list of beers
  const res = await fetch('https://api.sampleapis.com/beers/ale');

  if (res.ok) {
    console.log('*** retrieved sample beers!');
  } else {
    console.log('*** FAILED to retrieve sample beers!!');
    console.log('res.status:', res.status);
  }
  const beers = await res.json();

  // 2. Loop over each beer
  for (const beer of beers) {
    const nodeMeta = {
      id: createNodeId(`beer-${beer.name}`),
      parent: null,
      children: [],
      internal: {
        type: 'Beer',
        mediaType: 'application/json',
        contentDigest: createContentDigest(beer),
      },
    };

    // 3. Create a node for that beer
    actions.createNode({
      ...beer,
      ...nodeMeta,
    });
  }
};

const turnSlicemastersIntoPages = async ({ graphql, actions }) => {
  // 1. query all slicemasters
  const { data } = await graphql(`
    query {
      slicemasters: allSanityPerson {
        totalCount
        nodes {
          name
          id
          slug {
            current
          }
        }
      }
    }
  `);

  // TODO 2. turn each slicemaster into their own page
  data.slicemasters.nodes.forEach((slicemaster) => {
    actions.createPage({
      component: path.resolve('./src/templates/Slicemaster.js'),
      path: `/slicemaster/${slicemaster.slug.current}`,
      context: {
        name: slicemaster.name,
        slug: slicemaster.slug.current,
      },
    });
  });

  // 3. calculate number of pages
  const pageSize = parseInt(process.env.GATSBY_PAGE_SIZE);
  const pageCount = Math.ceil(data.slicemasters.totalCount / pageSize);

  // 4. loop from 1 to n (pages) and create page for each
  Array.from({ length: pageCount }).forEach((_, i) => {
    actions.createPage({
      path: `/slicemasters/${i + 1}`,
      component: path.resolve('./src/pages/slicemasters.js'),
      // this data is passed to the template
      context: {
        skip: i * pageSize,
        currentPage: i + 1,
        pageSize,
      },
    });
  });
};

export async function sourceNodes(params) {
  // fetch a list of beers and source them into our gatsby API!
  await Promise.all([fetchBeersAndTurnIntoNodes(params)]);
}

export async function createPages(params) {
  // create pages dynamically
  // 1. pizzas
  await Promise.all([
    turnPizzasIntoPages(params),
    turnToppingsIntoPages(params),
    turnSlicemastersIntoPages(params),
  ]);

  // 2. toppings
  // 3. slicemasters
}