mapbox-gl-flatgeobuf

A little library provides a tiled approach to consuming flatgeobuf files.

Note This library is compatible with both mapbox-gl and maplibre-gl.

Installation

npm install mapbox-gl-flatgeobuf

Basic Usage

  import FlatGeobuf from 'mapbox-gl-flatgeobuf'

  const fsSourceId = "fgb-src";

  new FlatGeobuf(fsSourceId, map, {
    url: "https://flatgeobuf.org/test/data/UScounties.fgb",
    minZoom: 8,
    idProperty: "FIPS",
  });

  map.addLayer({
    id: "fill-lyr",
    source: fsSourceId,
    type: "fill",
    paint: {
      "fill-opacity": 0.5,
      "fill-color": "#B42222",
    },
  });

API

This library exposes a single FlatGeobuf class

Constructor Options

Option	Type	Description
`sourceId`	`String` required	A string
`map`	`Object` required	A `mapbox-gl` or `maplibre-gl` `map` instance.
`flatGeobufOptions`	`Object` required	A range of options which will be used to access the flatgeobuf file. See below.
`geojsonSourceOptions`	`Object`	A object which will be passed to the creation of the mapbox-gl geojson source

FlatGeobuf Options

Option	Type	Default	Description
`url`	`String` required		The url of the flatgeobuf file eg `https://flatgeobuf.org/test/data/UScounties.fgb`.
`minZoom`	`Number` required	7	The zoom level to start requesting tiles.
`idProperty`	`String` required		An id field in the data to help minimise duplicate features being added to the map

Methods

Method	Description
destroySource()	Important The `destroySource()` method removes the source from the map and associated event listeners for retrieving data which request data as the map is panned, so it's important to call this method if removing the layer from the map completely.
disableRequests()	Important The `disableRequests()` method temporarily disables the associated event listeners for retrieving data which request data as the map is panned, you may want to call this if you toggle your layer off.
enableRequests()	Important The `enableRequests()` method enables the associated event listeners for retrieving data which request data as the map is panned. By default this is called by the constructor.

Example of disabling and enabling requests

It would be nice if disabling/enabling of requests happened automatically but unfortunantly I haven't found a way to make that happen because of how sources and layers are managed in mapbox-gl.

  const fsSourceId = "fgb-src";

  const fgb = new FlatGeobuf(fsSourceId, map, {
    url: "https://flatgeobuf.org/test/data/UScounties.fgb",
    minZoom: 8,
    idProperty: "FIPS",
  });
    
  const fgLyrId = 'fs-fill-lyr'
  map.addLayer({
    'id': fgLyrId,
    'source': fsSourceId,
    'type': 'fill',
    'paint': {
      'fill-opacity': 0.5,
      'fill-color': '#B42222'
    }
  })

  function hideFsLayer () {
      map.setLayoutProperty(fgLyrId, 'visibility', 'none')
      fgb.disableRequests()
  }

  function showFsLayer () {
      map.setLayoutProperty(fgLyrId, 'visibility', 'visible')
      fgb.enableRequests()
  }

  function removeFsCompletelyFromMap () {
    map.removeLayer(fgLyrId)
    fgb.destroySource()
  }

rowanwins/mapbox-gl-flatgeobuf