I am working on a map with Mapbox and Leaflet and I am supposed to let the user draw polygons and calculate and show the are of that polygon and I also need to let the user draw a polyline and show the distance of the polyline.

I have figured out the polygon area feature but I cannot figure out how to calculate the distance of a polyline.

My code is as follows:

loadScript('https://api.tiles.mapbox.com/mapbox.js/plugins/leaflet-draw/v0.2.2/leaflet.draw.js', function(){

    loadScript('https://api.tiles.mapbox.com/mapbox.js/plugins/leaflet-geodesy/v0.1.0/leaflet-geodesy.js', function(){

        var featureGroup = L.featureGroup().addTo(map);



        var drawControl = new L.Control.Draw({

        edit: {

            featureGroup: featureGroup

        },

        draw: {

            polygon: true,

            polyline: true,

            rectangle: false,

            circle: false,

            marker: false

        }

    }).addTo(map);



    map.on('draw:created', showPolygonArea);

    map.on('draw:edited', showPolygonAreaEdited);



    function showPolygonAreaEdited(e) {

        e.layers.eachLayer(function(layer) {

            showPolygonArea({ layer: layer });

        });

    }

    function showPolygonArea(e) {

        var type = e.layerType,

        layer = e.layer;



        if (type === 'polygon') {

            featureGroup.clearLayers();

            featureGroup.addLayer(e.layer);

            e.layer.bindPopup(((LGeo.area(e.layer) / 1000000) * 0.62137).toFixed(2) + ' mi<sup>2</sup>');

            e.layer.openPopup();

        }



        if (type === 'polyline') {

            featureGroup.clearLayers();

            featureGroup.addLayer(e.layer);

            // What do I do different here to calculate the distance of the polyline?

            // Is there a method in the LGeo lib itself?

            // e.layer.bindPopup(((LGeo.area(e.layer) / 1000000) * 0.62137).toFixed(2) + ' mi<sup>2</sup>');

            e.layer.openPopup();

        }



    }

    });

});

Is there a method in the LGeo lib itself which will help me calculate the distance of the polyline? The devs at geogson.io also have a way to calculate the distance but I cannot seem to figure it out looking at their code. I am not a seasoned Javascript developer. Any help is welcome. :)