maptalks.formats

This is a work inspired by leaflet-omnivore.

A maptalks.js's plugin for geographic data format supports, convert various data formats to GeoJSON.

It currently supports:

• CSV (via csv2geojson)
• GPX (via toGeoJSON)
• KML (via toGeoJSON)
• WKT (via wellknown)
• TopoJSON
• OSM
• Encoded Polylines via polyline

Installation

download maptalks.formats.min.js from this repository.

or

npm install maptalks.formats --save

example

maptalks.Formats.geojson('a.geojson', function (err, geojson) { });
maptalks.Formats.csv('a.csv', function (err, geojson) { });
maptalks.Formats.gpx('a.gpx', function (err, geojson) { });
maptalks.Formats.kml('a.kml', function (err, geojson) { });
maptalks.Formats.wkt('a.wkt', function (err, geojson) { });
maptalks.Formats.osm('osm.osm', function (err, geojson) { });
maptalks.Formats.topojson('a.topojson', function (err, geojson) { });
maptalks.Formats.polyline('a.txt', function (err, geojson) { });

API

Arguments with ? are optional. parser_options consists of options sent to the parser library:

• .csv(url, parser_options?, callback): Load & parse CSV. Options are the same as csv2geojson: latfield, lonfield, delimiter
• .csv.parse(csvString, parser_options?, callback): Parse CSV, and return layer.
• .kml(url, callback): Load & parse KML.
• .kml.parse(kmlString | gpxDom): Parse KML from a string of XML or XML DOM.
• .gpx(url, callback): Load & parse GPX.
• .gpx.parse(gpxString | gpxDom): Parse GPX from a string of XML or XML DOM.
• .geojson(url, callback): Load GeoJSON file at URL, parse GeoJSON.
• .wkt(url, callback): Load & parse WKT.
• .wkt.parse(wktString): Parse WKT.
• .topojson(url, callback): Load & parse TopoJSON.
• .topojson.parse(topojson): Parse TopoJSON (given as a string or object).
• .osm(url, callback): Parse OSM & Converts OSM XML to GeoJSON.
• .polyline(url, parser_options?, callback): Load & parse polyline.
• .polyline.parse(txt, options): Parse polyline (given as a string or object).

Valid options:

polyline

• precision will change how the polyline is interpreted. By default, the value is 5. This is the factor in the algorithm, by default 1e5, which is adjustable.

Async & Events

Each function returns an maptalks.Formats instance. Functions that load from URLs are asynchronous, so they will not be immediately loaded.

var map = new maptalks.Map('map', options);

maptalks.Formats.gpx('a.gpx', function (err, geojson) {
    // callback when loaded
    new maptalks.VectorLayer('gpx', geojson).addTo(map);
});

Development

git clone [email protected]:maptalks/maptalks.formats.git

cd maptalks.formats

# to run tests
npm install

# to build maptalks.formats.js
npm run build

maptalks.formats.js and maptalks.formats.min.js are built files generated from index.js by rollup. If you find an issue, it either needs to be fixed in index.js, or in one of the libraries maptalks.formats uses to parse formats.

FAQ

• What if I just want one format? Lucky for you, each format is specified in a different module, so you can just use TopoJSON, csv2geojson, wellknown, or toGeoJSON individually.
• My AJAX request is failing for a cross-domain request. Read up on the Same Origin Restriction. By default, we use corslite, so cross-domain requests will try to use CORS if your server and browser supports it, but if one of them doesn't, there's no way on the internet to support your request.
• Why isn't JSONP supported? Here's why.