Leaflet layer to WKT

LeafletToWKT.js

function toWKT(layer) {
    var lng, lat, coords = [];
    if (layer instanceof L.Polygon || layer instanceof L.Polyline) {
        var latlngs = layer.getLatLngs();
        for (var i = 0; i < latlngs.length; i++) {
	    	latlngs[i]
	    	coords.push(latlngs[i].lng + " " + latlngs[i].lat);
	        if (i === 0) {
	        	lng = latlngs[i].lng;
	        	lat = latlngs[i].lat;
	        }
	};
        if (layer instanceof L.Polygon) {
            return "POLYGON((" + coords.join(",") + "," + lng + " " + lat + "))";
        } else if (layer instanceof L.Polyline) {
            return "LINESTRING(" + coords.join(",") + ")";
        }
    } else if (layer instanceof L.Marker) {
        return "POINT(" + layer.getLatLng().lng + " " + layer.getLatLng().lat + ")";
    }
}

A simple little function for generating Well Known Text (WKT) from a Leaflet layer. This can be used with the excellent Leaflet.draw plugin when you want to save the layer geometry back to your database. Can be used as follows:

var drawnItems = new L.LayerGroup();
map.on('draw:created', function (e) {
    var type = e.layerType;
    var layer = e.layer;
    drawnItems.addLayer(layer);
    console.log(toWKT(layer));
});
map.addLayer(drawnItems);

Removed jQuery dependency.

thank's a lot, this is great

Thanks for sharing!

This little hack is no longer necessary now that you can combine Leaflet's toGeoJSON() method with the excellent Terraformer library. Make sure to include Terraformer core and the WKT Parser scripts to your Leaflet page and have the draw event spit out some WKT for inserting into your database:

map.on('draw:created', function (e) {
    var geojson = e.layer.toGeoJSON();
    var wkt = Terraformer.WKT.convert(geojson.geometry);
    console.log(wkt);
    drawnItems.addLayer(e.layer);
});

WTF at line 6????

latlngs[i]

Hello every body.

I tried to get wkt when draw.editstop but it doesnt work. What is wrong or what I need you to do, to get wkt when I edit a shape and stop draw.
Thank you.

map.on('draw:editstop', function (drawnItems) {
var geojson = drawnItems.toGeoJSON();
var wkt = Terraformer.WKT.convert(geojson.geometry);
alert(wkt);
});

My IMO better version.

function toWKT (layer) {
    var lng, lat, coords = [];
		if (layer instanceof L.Polygon || layer instanceof L.Polyline) {
			var latlngs = layer.getLatLngs();
		for (var i = 0; i < latlngs.length; i++) {
				var latlngs1 = latlngs[i];
				if (latlngs1.length){
				for (var j = 0; j < latlngs1.length; j++) {
					coords.push(latlngs1[j].lng + " " + latlngs1[j].lat);
					if (j === 0) {
						lng = latlngs1[j].lng;
						lat = latlngs1[j].lat;
					}
				}}
				else
				{
					coords.push(latlngs[i].lng + " " + latlngs[i].lat);
					if (i === 0) {
						lng = latlngs[i].lng;
						lat = latlngs[i].lat;
					}}
		};
			if (layer instanceof L.Polygon) {
				return "POLYGON((" + coords.join(",") + "," + lng + " " + lat + "))";
			} else if (layer instanceof L.Polyline) {
				return "LINESTRING(" + coords.join(",") + ")";
			}
		} else if (layer instanceof L.Marker) {
			return "POINT(" + layer.getLatLng().lng + " " + layer.getLatLng().lat + ")";
		}
	};
	map.on('draw:edited', function (e) {
		e.layers.eachLayer(function(layer) {
    		console.log(toWKT(layer));
    	});
	});
	map.on('draw:created', function (e) {
		var layer = e.layer;
		console.log(toWKT(layer));
		});

My IMO better version.

function toWKT (layer) {
    var lng, lat, coords = [];
		if (layer instanceof L.Polygon || layer instanceof L.Polyline) {
			var latlngs = layer.getLatLngs();
		for (var i = 0; i < latlngs.length; i++) {
				var latlngs1 = latlngs[i];
				if (latlngs1.length){
				for (var j = 0; j < latlngs1.length; j++) {
					coords.push(latlngs1[j].lng + " " + latlngs1[j].lat);
					if (j === 0) {
						lng = latlngs1[j].lng;
						lat = latlngs1[j].lat;
					}
				}}
				else
				{
					coords.push(latlngs[i].lng + " " + latlngs[i].lat);
					if (i === 0) {
						lng = latlngs[i].lng;
						lat = latlngs[i].lat;
					}}
		};
			if (layer instanceof L.Polygon) {
				return "POLYGON((" + coords.join(",") + "," + lng + " " + lat + "))";
			} else if (layer instanceof L.Polyline) {
				return "LINESTRING(" + coords.join(",") + ")";
			}
		} else if (layer instanceof L.Marker) {
			return "POINT(" + layer.getLatLng().lng + " " + layer.getLatLng().lat + ")";
		}
	};
	map.on('draw:edited', function (e) {
		e.layers.eachLayer(function(layer) {
    		console.log(toWKT(layer));
    	});
	});
	map.on('draw:created', function (e) {
		var layer = e.layer;
		console.log(toWKT(layer));
		});

Works very well, thank you!!

hello...Can I use this code to convert leaflettowkt ?? Do I need to add any reference ?

@bmcbride Thank you :)
I confirm this solution is still valid in 2020
Add this two lib¨

<script type="text/javascript" src="https://unpkg.com/terraformer@1.0.7/terraformer.js"></script>
<script type="text/javascript" src="https://unpkg.com/terraformer-wkt-parser@1.1.2/terraformer-wkt-parser.js"></script>

This little hack is no longer necessary now that you can combine Leaflet's toGeoJSON() method with the excellent Terraformer library. Make sure to include Terraformer core and the WKT Parser scripts to your Leaflet page and have the draw event spit out some WKT for inserting into your database:

map.on('draw:created', function (e) {
    var geojson = e.layer.toGeoJSON();
    var wkt = Terraformer.WKT.convert(geojson.geometry);
    console.log(wkt);
    drawnItems.addLayer(e.layer);
});