GeoJSON

GeoJSON is the GeoJSON utility object of maptalks (not a geometry class). It converts between GeoJSON data and maptalks Geometry, and provides async paged conversion for large datasets and remote file fetching. It is a namespace object whose methods are all called statically; it cannot be instantiated.

import { GeoJSON } from "maptalks";

const geos = GeoJSON.toGeometry(collection, geo => geo.config("draggable", true));

Methods

• toGeometry(geoJSON, foreachFn?, filterFn?): Geometry | Geometry[] — Converts one or more GeoJSON objects to geometry. geoJSON can be an object, an array of objects or a GeoJSON string; foreachFn is called for each geometry and filterFn filters the results. Returns an array of geometries when the input is a FeatureCollection.
• toGeometryAsync(geoJSON, foreachFn?, countPerTime?, filterFn?): Promise<Geometry[]> — Async paged conversion that converts at most countPerTime (default 2000) features per frame without blocking the main thread, returning a Promise.
• fetch(url, countPerTime?): Promise<object> — Fetches a large GeoJSON file asynchronously via a Worker (default 2000 features per page) to avoid blocking the main thread, resolving a FeatureCollection object.

// Async paged conversion
GeoJSON.toGeometryAsync(geoJSON).then(geos => {
  console.log(geos);
});

// Fetch a large file via a Worker
GeoJSON.fetch("https://abc.com/file.geojson", 2000).then(geojson => {
  console.log(geojson);
});