vt-geojson

vt-geojson

Extract GeoJSON from Mapbox vector tiles.

Usage

CLI

Install with npm install -g vt-geojson, and then:

vt-geojson /path/to/tiles.mbtiles --bounds minx miny maxx maxy
cat bounding_polygon.geojson | vt-geojson tilejson+http://api.tiles.mapbox.com/v4/YOUR-MAPID?access_token=YOUR_MAPBOX_TOKEN -z 12
vt-geojson someone.blahblah --tile tilex tiley tilez # ('someone.blahblah' is a mapid)

Node

First npm install vt-geojson and then:

var cover = require('tile-cover')
var vtGeoJson = require('vt-geojson')

var polygon = JSON.parse(fs.readFileSync('my-polygon.geojson'))
var source = 'tilejson+http://api.tiles.mapbox.com/v4/YOUR-MAPID?access_token=YOUR_MAPBOX_TOKEN'

// get an array of tiles ([x, y, z]) that we want to pull data from.
var tiles = cover.tiles(polygon.geometry, { min_zoom: 10, max_zoom: 12 })

// stream geojson from the chosen tiles:
vtGeoJson(source, tiles)
  .on('data', function (feature) {
    console.log("it's a GeoJSON feature!", feature.geometry.type, feature.properties)
  })
  .on('end', function () {
    console.log('all done')
  })

Browser

This module should work with browserify. There's a minimal example of using it in the browser here. Try it with:

npm install -g budo
budo example/browser.js

Then go to http://localhost:9966/?mapid=mapbox.mapbox-streets-v6&tile=73/97/8&layers=road&access_token=YOUR_MAPBOX_ACCESS_TOKEN

API

vtgeojson

Stream GeoJSON from a Mapbox Vector Tile source

Parameters

• uri string the tilelive URI for the vector tile source to use.
• options object options
  • options.layers Array<string> An array of layer names to read from tiles. If empty, read all layers
  • options.tiles Array The tiles to read from the tilelive source. If empty, use options.bounds instead.
  • options.bounds Array The [minx, miny, maxx, maxy] bounds or a GeoJSON Feature, FeatureCollection, or Geometry defining the region to read from source. Ignored if options.tiles is set. If empty, use the bounds from the input source's metadata.
  • options.minzoom number Defaults to the source metadata minzoom. Ignored if options.tiles is set.
  • options.maxzoom number Defaults to the source metadata minzoom. Ignored if options.tiles is set.
  • options.tilesOnly boolean Output [z, y, x] tile coordinates instead of actually reading tiles. Useful for debugging.
  • options.strict boolean Emit an error and end the stream if a tile is not found or can't be read

Returns ReadableStream<Feature> A stream of GeoJSON Feature objects. Emits warning events with { tile, error } when a tile from the requested set is not found or can't be read.

Contributing

This is an OPEN Open Source Project. This means that:

Individuals making significant and valuable contributions are given commit-access to the project to contribute as they see fit. This project is more like an open wiki than a standard guarded open source project.