vector-tile
This library reads Mapbox Vector Tiles and allows access to the layers and features.
Example
import {VectorTile} from '@mapbox/vector-tile';
import Protobuf from 'pbf';
const tile = new VectorTile(new Protobuf(data));
// Contains a map of all layers
tile.layers;
const landuse = tile.layers.landuse;
// Amount of features in this layer
landuse.length;
// Returns the first feature
landuse.feature(0);
Vector tiles contained in serialtiles-spec
are gzip-encoded, so a complete example of parsing them with the native
zlib module would be:
import {VectorTile} from '@mapbox/vector-tile';
import Protobuf from 'pbf';
import {gunzipSync} from 'zlib';
const buffer = gunzipSync(data);
const tile = new VectorTile(new Protobuf(buffer));
Install
To install:
npm install @mapbox/vector-tile
API Reference
VectorTile
An object that parses vector tile data and makes it readable.
Constructor
- new VectorTile(protobuf[, end]) —
parses the vector tile data contained in the given Protobuf object,
saving resulting layers in the created object as a
layers property. Optionally accepts end index.
Properties
- layers (Object) — an object containing parsed layers in the form of
{<name>: <layer>, ...},
where each layer is a VectorTileLayer object.
VectorTileLayer
An object that contains the data for a single vector tile layer.
Properties
- version (
Number, default: 1)
- name (
String) — layer name
- extent (
Number, default: 4096) — tile extent size
- length (
Number) — number of features in the layer
Methods
- feature(i) — get a feature (
VectorTileFeature) by the given index from the layer.
VectorTileFeature
An object that contains the data for a single feature.
Properties
- type (
Number) — type of the feature (also see VectorTileFeature.types)
- extent (
Number) — feature extent size
- id (
Number) — feature identifier, if present
- properties (
Object) — object literal with feature properties
Methods
- loadGeometry() — parses feature geometry and returns an array of
Point arrays (with each point having
x and y properties)
- bbox() — calculates and returns the bounding box of the feature in the form
[x1, y1, x2, y2]
- toGeoJSON(x, y, z) — returns a GeoJSON representation of the feature. (
x, y, and z refer to the containing tile's index.)
