@loaders.gl/mvt/src/mvt-loader.ts

Loader for Mapbox Vector Tiles

// loaders.gl
// SPDX-License-Identifier: MIT
// Copyright vis.gl contributors

import type {Loader, LoaderWithParser, LoaderOptions} from '@loaders.gl/loader-utils';
// import type {MVTOptions} from './lib/types';
import {parseMVT} from './lib/parse-mvt';
import {MVTFormat} from './mvt-format';

// __VERSION__ is injected by babel-plugin-version-inline
// @ts-ignore TS2304: Cannot find name '__VERSION__'.
const VERSION = typeof __VERSION__ !== 'undefined' ? __VERSION__ : 'latest';

export type MVTLoaderOptions = LoaderOptions & {
  mvt?: {
    /** Shape of returned data */
    shape?: 'geojson-table' | 'columnar-table' | 'geojson' | 'binary' | 'binary-geometry';
    /** `wgs84`: coordinates in long, lat (`tileIndex` must be provided. `local` coordinates are `0-1` from tile origin */
    coordinates?: 'wgs84' | 'local';
    /** An object containing tile index values (`x`, `y`, `z`) to reproject features' coordinates into WGS84. Mandatory with `wgs84` coordinates option. */
    tileIndex?: {x: number; y: number; z: number};
    /** If provided, stored the layer name of each feature is added to `feature.properties[layerProperty]`. */
    layerProperty?: string | number;
    /** layer filter. If provided, only features belonging to the named layers will be included, otherwise features from all layers are returned. */
    layers?: string[];
    /** Override the URL to the worker bundle (by default loads from unpkg.com) */
    workerUrl?: string;
  };
  gis?: {
    /** @deprecated Use options.mvt.shape === 'binary-geometry' */
    binary?: boolean;
    /** @deprecated. Use options.mvt.shape */
    format?: 'geojson-table' | 'columnar-table' | 'geojson' | 'binary' | 'binary-geometry';
  };
};

/**
 * Worker loader for the Mapbox Vector Tile format
 */
export const MVTWorkerLoader = {
  ...MVTFormat,
  dataType: null as any,
  batchType: null as never,
  version: VERSION,
  worker: true,
  options: {
    mvt: {
      shape: 'geojson',
      coordinates: 'local',
      layerProperty: 'layerName',
      layers: undefined!,
      tileIndex: undefined!
    }
  }
} as const satisfies Loader<
  any, // BinaryFeatureCollection | GeoJSONTable | Feature<Geometry, GeoJsonProperties>,
  never,
  MVTLoaderOptions
>;

/**
 * Loader for the Mapbox Vector Tile format
 */
export const MVTLoader = {
  ...MVTWorkerLoader,
  parse: async (arrayBuffer, options?: MVTLoaderOptions) => parseMVT(arrayBuffer, options),
  parseSync: parseMVT,
  binary: true
} as const satisfies LoaderWithParser<
  any, // BinaryFeatureCollection | GeoJSONTable | Feature<Geometry, GeoJsonProperties>,
  never,
  MVTLoaderOptions
>;