В вашем коде есть опечатка / ошибка. Удалите эту строку:
path.push(src);
из этого l oop:
//Loop and Draw Path Route between the Points on MAP
for (var i = 0; i < lat_lng.length; i++) {
if ((i + 1) < lat_lng.length) {
var src = lat_lng[i];
var des = lat_lng[i + 1];
// path.push(src); <============================================ here
poly.setPath(path);
service.route({
origin: src,
destination: des,
travelMode: google.maps.DirectionsTravelMode.WALKING
}, function (result, status) {
if (status == google.maps.DirectionsStatus.OK) {
for (var i = 0, len = result.routes[0].overview_path.length; i < len; i++) {
path.push(result.routes[0].overview_path[i]);
}
}
});
}
}
Вторая проблема связана с асинхронной природой службы маршрутов. Порядок ответов от службы не гарантируется в том же порядке, в котором отправляются запросы. Самый простой способ исправить это - создать отдельную ломаную линию для каждого результата:
function(result, status) {
if (status == google.maps.DirectionsStatus.OK) {
//Initialize the Path Array
var path = new google.maps.MVCArray();
//Set the Path Stroke Color
var poly = new google.maps.Polyline({
map: map,
strokeColor: '#4986E7'
});
poly.setPath(path);
for (var i = 0, len = result.routes[0].overview_path.length; i < len; i++) {
path.push(result.routes[0].overview_path[i]);
}
}
});
подтверждение концепции скрипта
фрагмент кода:
var markers = [{
"timestamp": 'Alibaug',
"latitude": '18.641400',
"longitude": '72.872200',
"description": 'Alibaug is a coastal town and a municipal council in Raigad District in the Konkan region of Maharashtra, India.'
},
{
"timestamp": 'Mumbai',
"latitude": '18.964700',
"longitude": '72.825800',
"description": 'Mumbai formerly Bombay, is the capital city of the Indian state of Maharashtra.'
},
{
"timestamp": 'Pune',
"latitude": '18.523600',
"longitude": '73.847800',
"description": 'Pune is the seventh largest metropolis in India, the second largest in the state of Maharashtra after Mumbai.'
},
{
"timestamp": 'Bhopal',
"latitude": '23.2599',
"longitude": '73.857800',
"description": 'Pune is the seventh largest metropolis in India, the second largest in the state of Maharashtra after Mumbai.'
},
{
"timestamp": 'Bhopal',
"latitude": '26.9124',
"longitude": '75.7873',
"description": 'Pune is the seventh largest metropolis in India, the second largest in the state of Maharashtra after Mumbai.'
}
];
window.onload = function() {
var mapOptions = {
center: new google.maps.LatLng(markers[0].latitude, markers[0].longitude),
zoom: 10,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
var map = new google.maps.Map(document.getElementById("dvMap"), mapOptions);
var infoWindow = new google.maps.InfoWindow();
var lat_lng = new Array();
var latlngbounds = new google.maps.LatLngBounds();
for (i = 0; i < markers.length; i++) {
var data = markers[i]
var myLatlng = new google.maps.LatLng(data.latitude, data.longitude);
lat_lng.push(myLatlng);
var marker = new google.maps.Marker({
position: myLatlng,
map: map,
title: data.timestamp
});
// console.log(i)
latlngbounds.extend(marker.position);
(function(marker, data) {
google.maps.event.addListener(marker, "click", function(e) {
infoWindow.setContent(data.timestamp);
infoWindow.open(map, marker);
});
})(marker, data);
}
map.setCenter(latlngbounds.getCenter());
map.fitBounds(latlngbounds);
//***********ROUTING****************//
//Initialize the Direction Service
var service = new google.maps.DirectionsService();
//Loop and Draw Path Route between the Points on MAP
for (var i = 0; i < lat_lng.length; i++) {
if ((i + 1) < lat_lng.length) {
var src = lat_lng[i];
var des = lat_lng[i + 1];
// path.push(src);
service.route({
origin: src,
destination: des,
travelMode: google.maps.DirectionsTravelMode.WALKING
}, function(result, status) {
if (status == google.maps.DirectionsStatus.OK) {
//Initialize the Path Array
var path = new google.maps.MVCArray();
//Set the Path Stroke Color
var poly = new google.maps.Polyline({
map: map,
strokeColor: '#4986E7'
});
poly.setPath(path);
for (var i = 0, len = result.routes[0].overview_path.length; i < len; i++) {
path.push(result.routes[0].overview_path[i]);
}
}
});
}
}
}
/* Always set the map height explicitly to define the size of the div
* element that contains the map. */
#dvMap {
height: 100%;
}
/* Optional: Makes the sample page fill the window. */
html,
body {
height: 100%;
margin: 0;
padding: 0;
}
<div id="dvMap"></div>
<!-- Replace the value of the key parameter with your own API key. -->
<script async defer src="https://maps.googleapis.com/maps/api/js?key=AIzaSyCkUOdZ5y7hMm0yrcCQoCvLwzdM6M8s5qk&callback=initMap">
</script>