Get directions to predefined destination from current location (Geolocation)

Question

Nog I have following page with directions to the predefined destination: example directions

This is working perfect with following code:

Answer 1

Your current position is declared inside another fuction, so it's basically invisible to every other functions.

   navigator.geolocation.getCurrentPosition(function(position) {
      var pos = {
        lat: position.coords.latitude,
        lng: position.coords.longitude
      };

    }, function() {
      handleLocationError(true, markerme);
    });

I'd suggest calculating your position inside initMap and then passing your current position as a parameter to calculateAndDisplayRoute.

function initMap() {
    ...
    var map = new google.maps.Map(document.getElementById('map'), {
      zoom: JSON.parse(zoomtp),
      center: tp
    });
    directionsDisplay.setMap(map);

    if (navigator.geolocation) {
      navigator.geolocation.getCurrentPosition(function(position) {
        var pos = {
          lat: position.coords.latitude,
          lng: position.coords.longitude
        };
        calculateAndDisplayRoute(directionsService, directionsDisplay, pos);

      }, function() {
        handleLocationError(true, markerme);
       });
    } else {
     // Browser doesn't support Geolocation
     window.alert('Geolocation is not supported');
    }


 }

function calculateAndDisplayRoute(directionsService, directionsDisplay, pos) {
    var latrest = <?php echo json_encode($latrest);?>;
    var lngrest = <?php echo json_encode($lngrest);?>;
    var rest = {lat: JSON.parse(latrest), lng: JSON.parse(lngrest)};

    //var selectedMode = "WALKING";
    directionsService.route({
      origin: pos,  // current position.
      destination: rest,  // restaurant.
      // Note that Javascript allows us to access the constant
      // using square brackets and a string value as its
      // "property."
      travelMode: google.maps.TravelMode.WALKING
    }, function(response, status) {
      if (status == 'OK') {
        directionsDisplay.setDirections(response);
      } else {
        window.alert('Directions request failed due to ' + status);
      }
    });
}