Gatsby Create pages from API

gatsby-node.js

// Lightweight GraphQL generic client
const GraphQLClient = require('graphql-request').GraphQLClient;
const crypto = require('crypto');
const path = require('path');
const api = require('./api_constants');

//GraphQL query string to get all inventory, filtering by a specific dealer
const vehicles = `
{
	allDealerships(filter:{ name:"Wheel Kinetics"}) {
    inventory {
      id
      year
      make
      model
      stockNo
    }
  }
  
}
`
// sourceNodes is a Gatsby API
module.exports.sourceNodes = async ({ boundActionCreators }) => {
  const { createNode } = boundActionCreators
  const client = new GraphQLClient(api.development.main)
  const data = await client.request(vehicles)

  // Passes inventory array of objects to createNodes function
  // a node is created for each vehicle
  createNodes(createNode, data.allDealerships[0].inventory)
}

// called after sourceNodes
exports.createPages = ({ graphql, boundActionCreators }) => {
  const { createPage } = boundActionCreators
  return new Promise((resolve, reject) => {
    const template = path.resolve('src/templates/car.js');
    resolve(
        // query Gatbsy's GraphQL store for all vehiclePage nodes
        graphql(`
          {
            allVehiclePage(limit: 500) {
              edges {
                node {
                  field
                }
              }
            }
          }
        `)
        .then(result => {
          if (result.errors) {
            reject(result.errors);
          }
          result.data.allVehiclePage.edges.forEach(edge => {
            const fields = JSON.parse(edge.node.field);
            createPage({
              path: `${fields.make.split(' ').join('-')}-${fields.stockNo}`,
              component: template,
              context: {
                slug: `${fields.make.split(' ').join('-')}-${fields.stockNo}`,
                fields
              }
            })
          })
        })
    )
  })
}

function createNodes(fn, nodes) {
  nodes.forEach(node => {
    const jsonNode = JSON.stringify(node);
    fn({
      id: node.id,
      parent: null,
      field: jsonNode, // pass queried data into node
      children: [],
      internal: {
        type: 'VehiclePage',
        content: jsonNode,
        contentDigest: crypto.createHash(`md5`).update(jsonNode).digest(`hex`)
      }
    })
  })
}