gatsby-node.esm.js

import getInventory from './providers/inventoryProvider.js'
import { slugify } from './utils/helpers'

const ItemView = require.resolve('./src/templates/ItemView')
const CategoryView = require.resolve('./src/templates/CategoryView')

exports.createPages = async ({ graphql, actions }) => {
  const { createPage } = actions
  const inventory = await getInventory()

  createPage({
    path: 'all',
    component: CategoryView,
    context: {
      content: inventory,
      title: 'all',
      type: "categoryPage"
    },
  })


  const inventoryByCategory = inventory.reduce((acc, next) => {
    const categories = next.categories
    categories.forEach(c => {
      if (acc[c]) {
        acc[c].items.push(next)
      } else {
        acc[c] = {}
        acc[c].items = []
        acc[c].items.push(next)
      }
    })
    return acc
  }, {})

  const categories = Object.keys(inventoryByCategory)

  categories.map(async(category, index) => {
    const previous = index === categories.length - 1 ? null : categories[index + 1].node
    const next = index === 0 ? null : categories[index - 1]
    createPage({
      path: slugify(category),
      component: CategoryView,
      context: {
        content: inventoryByCategory[category],
        title: category,
        type: "categoryPage",
        previous,
        next,
      },
    })
  })

  inventory.map(async(item, index) => {
    const previous = index === inventory.length - 1 ? null : inventory[index + 1].node
    const next = index === 0 ? null : inventory[index - 1]
    createPage({
      path: slugify(item.name),
      component: ItemView,
      context: {
        content: item,
        title: item.name,
        type: "itemPage",
        previous,
        next,
      },
    })
  })
}

exports.sourceNodes = async ({ actions, createNodeId, createContentDigest }) => {
  const { createNode } = actions
  const inventory = await getInventory()

  /* create nav info for categories */ 
  const categoryNames = inventory.reduce((acc, next) =>  {
    next.categories.forEach(c => {
      if (!acc.includes(c)) acc.push(c)
    })
    return acc
  }, [])

  const navData = {
    key: 'nav-info',
    data: categoryNames
  }

  const navNodeContent = JSON.stringify(navData)
  const navNodeMeta = {
    id: createNodeId(`my-data-${navData.key}`),
    parent: null,
    children: [],
    internal: {
      type: `NavInfo`,
      mediaType: `json`,
      content: navNodeContent,
      contentDigest: createContentDigest(navData)
    }
  }

  const navNode = Object.assign({}, navData, navNodeMeta)
  createNode(navNode)

  /* create category info for home page */
  const inventoryByCategory = inventory.reduce((acc, next) => {
    const categories = next.categories

    categories.forEach(c => {
      const index = acc.findIndex(item => item.name === c)
      if (index !== -1) {
        const item = acc[index]
        item.itemCount = item.itemCount + 1
        acc[index] = item
      } else {
        const item = {
          name: c,
          image: next.image,
          itemCount: 1
        }
        acc.push(item)
      }
    })
    return acc
  }, [])

  const catData = {
    key: 'category-info',
    data: inventoryByCategory
  }

  const catNodeContent = JSON.stringify(catData)
  const catNodeMeta = {
    id: createNodeId(`my-data-${catData.key}`),
    parent: null,
    children: [],
    internal: {
      type: `CategoryInfo`,
      mediaType: `json`,
      content: catNodeContent,
      contentDigest: createContentDigest(catData)
    }
  }

  const catNode = Object.assign({}, catData, catNodeMeta)
  createNode(catNode)

  /* all inventory */
  const inventoryData = {
    key: 'all-inventory',
    data: inventory
  }

  const inventoryNodeContent = JSON.stringify(inventoryData)
  const inventoryNodeMeta = {
    id: createNodeId(`my-data-${inventoryData.key}`),
    parent: null,
    children: [],
    internal: {
      type: `InventoryInfo`,
      mediaType: `json`,
      content: inventoryNodeContent,
      contentDigest: createContentDigest(inventoryData)
    }
  }

  const inventoryNode = Object.assign({}, inventoryData, inventoryNodeMeta)
  createNode(inventoryNode)
}