@hyperbytes/wappler-distanmce-between-2-points/server_connect/modules/distance.js

Calculate distance between two points, in miles, km or nautical miles

// JavaScript Document
exports.distance = function (options) {
    options = this.parse(options);
    //units = units.toUpperCase();
    let distanceunits = (options.dunits == 'M') ? 0.62137 : (options.dunits == 'N') ? 0.539957 : 1;

    function toRad(v) { return v * Math.PI / 180; }


    function kmToMiles(km) { return (km * distanceunits).toFixed(2); }

    var l1 = LatLong(options.lat1, options.lon1);
    var l2 = LatLong(options.lat2, options.lon2);

    function LatLong(lat, lon) {
        return { Latitude: lat, Longitude: lon }
    }

    function haversine(l1, l2) {
        var R = 6371; // km 
        var x1 = l2.Latitude - l1.Latitude;
        var dLat = toRad(x1);
        var x2 = l2.Longitude - l1.Longitude;
        var dLon = toRad(x2);
        var a = Math.sin(dLat / 2) * Math.sin(dLat / 2) +
            Math.cos(toRad(l1.Latitude)) * Math.cos(toRad(l2.Latitude)) *
            Math.sin(dLon / 2) * Math.sin(dLon / 2);
        var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
        var d = R * c;
        return d;
    }

    return kmToMiles(haversine(l1, l2));
}