@koopjs/featureserver/src/response-handlers/helpers/send-pbf/transform-features-for-pbf.js

*An open source implementation of the GeoServices specification*

const _ = require('lodash');
const { getGeometryTransform } = require('./get-geometry-transform');
const { transformToPbfAttributes } = require('./transform-to-pbf-attributes');
const { transformToPbfGeometry } = require('./transform-to-pbf-geometry');

function transformFeaturesForPbf(json, quantizationParameters) {
  const {
    objectIdFieldName,
    uniqueIdField,
    geometryType,
    spatialReference,
    exceededTransferLimit,
  } = json;
  const fields = _.orderBy(json.fields, ['name'], ['asc']);

  const geometryTransform = getGeometryTransform(spatialReference, quantizationParameters);

  const features = json.features.map(transformFeatureFunction(fields, geometryTransform));

  return {
    objectIdFieldName,
    uniqueIdField,
    spatialReference,
    fields: fields.map(({ name, alias, type }) => ({
      name,
      alias,
      fieldType: type,
    })),
    features,
    exceededTransferLimit,
    transform: geometryTransform,
    geometryType: geometryType
      ? geometryType.replace('esriGeometry', 'esriGeometryType')
      : 'esriGeometryTypeNone',
  };
}

function transformFeatureFunction(fields, geometryTransform) {
  const fieldMap = fields.reduce((acc, cur) => {
    acc[cur.name] = cur.type;
    return acc;
  }, {});

  return (feature) => {
    const attributes = transformToPbfAttributes(feature.attributes, fieldMap);

    const geometry = transformToPbfGeometry(feature.geometry, geometryTransform);

    return {
      attributes,
      geometry,
    };
  };
}

module.exports = {
  transformFeaturesForPbf,
};