featureserver/lib/queryRelatedRecords.js

*An open source implementation of the GeoServices specification*

const _ = require('lodash')
const { getCollectionCrs, getGeometryTypeFromGeojson } = require('./helpers')
const {
  QueryFields
} = require('./helpers/fields')

module.exports = queryRelatedRecords

function queryRelatedRecords (data, params = {}) {
  const response = {
    relatedRecordGroups: []
  }

  if (!params.returnCountOnly) response.fields = QueryFields.create({ ...data, ...params })

  const geomType = getGeometryTypeFromGeojson(data)
  if (geomType) {
    response.geomType = geomType
    response.spatialReference = getCollectionCrs(data)
    response.hasZ = false
    response.hasM = false
  }

  if (data.features) {
    response.relatedRecordGroups = data.features.map(featureCollection => {
      return convertFeaturesToRelatedRecordGroups(featureCollection, params.returnCountOnly)
    })
  }

  return response
}

function convertFeaturesToRelatedRecordGroups ({ features, properties }, returnCountOnly = false) {
  const recordGroup = {
    objectId: properties.objectid
  }

  if (returnCountOnly) {
    // allow for preprocessing of count within provider
    if (properties.count || properties.count === 0) {
      recordGroup.count = properties.count
    } else {
      recordGroup.count = _.get(features, 'length', 0)
    }

    return recordGroup
  }

  if (features) {
    recordGroup.relatedRecords = features.map(({ geometry, properties }) => {
      return {
        attributes: properties,
        geometry: geometry
      }
    })
  }

  return recordGroup
}