gatsby-node.js

const MongoClient = require(`mongodb`).MongoClient
const crypto = require(`crypto`)
const prepareMappingChildNode = require(`./mapping`)
const sanitizeName = require(`./sanitize-name`)
const _ = require(`lodash`)
const queryString = require(`query-string`)

exports.sourceNodes = (
  { actions, getNode, createNodeId, hasNodeChanged },
  pluginOptions
) => {
  const { createNode } = actions

  let serverOptions = pluginOptions.server || {
    address: `localhost`,
    port: 27017,
  }
  let dbName = pluginOptions.dbName || `local`,
    authUrlPart = ``
  if (pluginOptions.auth)
    authUrlPart = `${pluginOptions.auth.user}:${pluginOptions.auth.password}@`

  let connectionExtraParams = getConnectionExtraParams(
    pluginOptions.extraParams
  )
  const connectionURL = `mongodb://${authUrlPart}${serverOptions.address}:${
    serverOptions.port
  }/${dbName}${connectionExtraParams}`

  return MongoClient.connect(connectionURL)
    .then(db => {
      let collection = pluginOptions.collection || [`documents`]
      if (!Array.isArray(collection)) {
        collection = [collection]
      }

      return Promise.all(
        collection.map(col =>
          createNodes(db, pluginOptions, dbName, createNode, createNodeId, col)
        )
      )
        .then(() => {
          db.close()
        })
        .catch(err => {
          console.warn(err)
          db.close()
          return err
        })
    })
    .catch(err => {
      console.warn(err)
      return err
    })
}

function createNodes(
  db,
  pluginOptions,
  dbName,
  createNode,
  createNodeId,
  collectionName
) {
  return new Promise((resolve, reject) => {
    let collection = db.collection(collectionName)
    let cursor = collection.find()

    // Execute the each command, triggers for each document
    cursor.toArray((err, documents) => {
      if (err) {
        reject(err)
      }

      documents.forEach(item => {
        var id = item._id.toString()
        delete item._id

        var node = {
          // Data for the node.
          ...item,
          id: createNodeId(`${id}`),
          mongodb_id: id,
          parent: `__${collectionName}__`,
          children: [],
          internal: {
            type: `mongodb${sanitizeName(dbName)}${sanitizeName(
              collectionName
            )}`,
            content: JSON.stringify(item),
            contentDigest: crypto
              .createHash(`md5`)
              .update(JSON.stringify(item))
              .digest(`hex`),
          },
        }
        const childrenNodes = []
        if (pluginOptions.map) {
          let mapObj = pluginOptions.map
          if (pluginOptions.map[collectionName]) {
            mapObj = pluginOptions.map[collectionName]
          }
          // We need to map certain fields to a contenttype.
          Object.keys(mapObj).forEach(mediaItemFieldKey => {
            if (
              node[mediaItemFieldKey] &&
              (typeof mapObj[mediaItemFieldKey] === `string` ||
                mapObj[mediaItemFieldKey] instanceof String)
            ) {
              const mappingChildNode = prepareMappingChildNode(
                node,
                mediaItemFieldKey,
                node[mediaItemFieldKey],
                mapObj[mediaItemFieldKey],
                createNode
              )

              node[`${mediaItemFieldKey}___NODE`] = mappingChildNode.id
              childrenNodes.push(mappingChildNode)

              delete node[mediaItemFieldKey]
            }
          })
        }
        createNode(node)
        childrenNodes.forEach(node => {
          createNode(node)
        })
      })
      resolve()
    })
  })
}

function getConnectionExtraParams(extraParams) {
  let connectionSuffix
  if (extraParams) {
    connectionSuffix = queryString.stringify(extraParams, { sort: false })
  }

  return connectionSuffix ? `?` + connectionSuffix : ``
}