winnow/lib/normalize-query-options/date-fields.js

Apply sql-like filters to GeoJSON

const _ = require('lodash')
/**
 * @param {object} collection - the GeoJSON object from Koop (with features omitted)
 * @param {*} requestedFields
 */
function deriveDateFields (collection, requestedFields) {
  if (!_.get(collection, 'metadata.fields')) return []

  return collection.metadata.fields.filter(({ type, name }) => {
    return type === 'Date' && (requestedFields === undefined || requestedFields.indexOf(name) > -1)
  }).map(({ name }) => {
    return name
  })
}

module.exports = deriveDateFields