Check existence of point on leaflet route

Question

Is there are a method on leaflet routing machine that checks if a specific point, e.g (lat,lng), is inside the routing polyline ?

Answer 1

There is not, but it's still doable using Leaflet.GeometryUtil

Take a look at the belongsSegment function:

belongsSegment(latlng, latlngA, latlngB, toleranceopt, nullable) → {boolean}

Returns true if the latlng belongs to segment A-B

So when a route is selected in Routing Machine, you are checking for every segment of a polyline if the point belongs to it with a given tolerance:

var point = {your specific point};
...
map.on('routeselected', function(e) {
    var route = e.route;
    isPointOnLine(point, route.coordinates));
})

where isPointOnLine is

function isPointOnLine(point, path) {
    for (var i = 0; i < path.length - 1; i++) {
        if (L.GeometryUtil.belongsSegment(point, path[i], path[i + 1])) {
            return true;
        }
    }
    return false;
}