Track a vehicle

This section shows how to use the JavaScript fleet tracking library to track a vehicle for on-demand trips or scheduled tasks.

To track a vehicle, you do these steps:

1. Load the library and initialize the map view
2. Provide the vehicle location and map view
3. Listen for events and handle errors
4. Stop tracking

Load the library and initialize the map view

To display your fleet operations on a map in your web page, use a script that calls a map using your API key. The following example shows how to do this from HTML:

• URL source: Calls the google maps API to request a map using your API key.

• callback parameter: Runs the initMap function after the API returns the call.

• libraries parameter: Loads the Fleet tracking library.

• defer attribute: Lets the browser continue rendering the rest of your page while the API loads.

  <script src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&callback=initMap&libraries=journeySharing" defer></script>
  

Provide the vehicle location and map view

To start tracking a vehicle, you both instantiate a vehicle location provider and initialize a map view with the vehicle ID as described in the following sections.

Instantiate a vehicle location provider

The JavaScript fleet tracking library includes a location provider for the Fleet Engine API. Use your project ID and a reference to your token fetcher to instantiate it as shown in the following examples.

On-demand trips

locationProvider =
    new google.maps.journeySharing
        .FleetEngineVehicleLocationProvider({
          projectId,
          authTokenFetcher,

          // Optionally, you may specify
          // vehicleId to immediately start
          // tracking.
          vehicleId: 'your-vehicle-id',
});

locationProvider =
    new google.maps.journeySharing
        .FleetEngineVehicleLocationProvider({
          projectId,
          authTokenFetcher,

          // Optionally, you may specify
          // vehicleId to immediately start
          // tracking.
          vehicleId: 'your-vehicle-id',
});

Scheduled tasks

locationProvider =
    new google.maps.journeySharing
        .FleetEngineDeliveryVehicleLocationProvider({
          projectId,
          authTokenFetcher,

          // Optionally, you may specify
          // deliveryVehicleId to immediately start
          // tracking.
          deliveryVehicleId: 'your-delivery-id',
});

locationProvider =
    new google.maps.journeySharing
        .FleetEngineDeliveryVehicleLocationProvider({
          projectId,
          authTokenFetcher,

          // Optionally, you may specify
          // deliveryVehicleId to immediately start
          // tracking.
          deliveryVehicleId: 'your-delivery-id',
});

Initialize the map view

After loading the JavaScript Journey Sharing library, initialize the map view and add it to the HTML page. Your page should contain a <div> element that holds the map view. The <div> element is named map_canvas in the following examples.=

On-demand trips

const mapView = new
    google.maps.journeySharing.JourneySharingMapView({
  element: document.getElementById('map_canvas'),
  locationProviders: [locationProvider],
});

// If you did not specify a vehicle ID in the
// location provider constructor, you may do so here.
// Location tracking will start as soon as this is set.
locationProvider.vehicleId
                        = 'your-vehicle-id';

// Give the map an initial viewport to allow it to
// initialize; otherwise the 'ready' event above may
// not fire. The user also has access to the mapView
// object to customize as they want.
mapView.map.setCenter('Times Square, New York, NY');
mapView.map.setZoom(14);

const mapView = new
    google.maps.journeySharing.JourneySharingMapView({
  element: document.getElementById('map_canvas'),
  locationProviders: [locationProvider],
});

// If you did not specify a vehicle ID in the
// location provider constructor, you may do so here.
// Location tracking will start as soon as this is set.
locationProvider.VehicleId
                        = 'your-vehicle-id';

// Give the map an initial viewport to allow it to
// initialize; otherwise the 'ready' event above may
// not fire. The user also has access to the mapView
// object to customize as they want.
mapView.map.setCenter('Times Square, New York, NY');
mapView.map.setZoom(14);

Scheduled tasks

const mapView = new
    google.maps.journeySharing.JourneySharingMapView({
  element: document.getElementById('map_canvas'),
  locationProviders: [locationProvider],
});

// If you did not specify a delivery vehicle ID in the
// location provider constructor, you may do so here.
// Location tracking will start as soon as this is set.
locationProvider.deliveryVehicleId
                        = 'your-delivery-vehicle-id';

// Give the map an initial viewport to allow it to
// initialize; otherwise the 'ready' event above may
// not fire. The user also has access to the mapView
// object to customize as they want.
mapView.map.setCenter('Times Square, New York, NY');
mapView.map.setZoom(14);

const mapView = new
    google.maps.journeySharing.JourneySharingMapView({
  element: document.getElementById('map_canvas'),
  locationProviders: [locationProvider],
});

// If you did not specify a delivery vehicle ID in the
// location provider constructor, you may do so here.
// Location tracking will start as soon as this is set.
locationProvider.deliveryVehicleId
                        = 'your-delivery-vehicle-id';

// Give the map an initial viewport to allow it to
// initialize; otherwise the 'ready' event above may
// not fire. The user also has access to the mapView
// object to customize as they want.
mapView.map.setCenter('Times Square, New York, NY');
mapView.map.setZoom(14);

Listen for events and handle errors

Once you've started tracking a vehicle, you want to update its progress on a map and handle errors as the vehicle travels along its route.

Listen for vehicle events

To track the progress of a vehicle for on-demand trips or scheduled tasks, you need to listen for change events.

You retrieve meta from the vehicle or deliveryVehicle object using the location provider. The meta information includes the ETA and remaining distance before the vehicle's next pickup or dropoff. Changes to the meta information trigger an update event in the location provider.

The following example shows how to listen to these change events.

On-demand trips

locationProvider.addListener('update', e => {
  // e.vehicle contains data that may be
  // useful to the rest of the UI.
  if (e.vehicle) {
    console.log(e.vehicle.vehicleState);
  }
});

locationProvider.addListener('update',
    (e: google.maps.journeySharing.FleetEngineVehicleLocationProviderUpdateEvent) => {
  // e.vehicle contains data that may be
  // useful to the rest of the UI.
  if (e.vehicle) {
    console.log(e.vehicle.vehicleState);
  }
});

Scheduled tasks

locationProvider.addListener('update', e => {
  // e.deliveryVehicle contains data that may be
  // useful to the rest of the UI.
  if (e.deliveryVehicle) {
    console.log(e.deliveryVehicle.remainingDuration);
  }
});

locationProvider.addListener('update',
    (e: google.maps.journeySharing.FleetEngineDeliveryVehicleLocationProviderUpdateEvent) => {
  // e.deliveryVehicle contains data that may be
  // useful to the rest of the UI.
  if (e.deliveryVehicle) {
    console.log(e.deliveryVehicle.remainingDuration);
  }
});

Handle errors

After loading the JavaScript Journey Sharing library, initialize the map view and add it to the HTML page. Your page should contain a <div> element that holds the map view. The <div> element is named map_canvas in the following examples.=

On-demand trips

const mapView = new
    google.maps.journeySharing.JourneySharingMapView({
  element: document.getElementById('map_canvas'),
  locationProviders: [locationProvider],
});

// If you did not specify a vehicle ID in the
// location provider constructor, you may do so here.
// Location tracking will start as soon as this is set.
locationProvider.vehicleId
                        = 'your-vehicle-id';

// Give the map an initial viewport to allow it to
// initialize; otherwise the 'ready' event above may
// not fire. The user also has access to the mapView
// object to customize as they want.
mapView.map.setCenter('Times Square, New York, NY');
mapView.map.setZoom(14);

const mapView = new
    google.maps.journeySharing.JourneySharingMapView({
  element: document.getElementById('map_canvas'),
  locationProviders: [locationProvider],
});

// If you did not specify a vehicle ID in the
// location provider constructor, you may do so here.
// Location tracking will start as soon as this is set.
locationProvider.VehicleId
                        = 'your-vehicle-id';

// Give the map an initial viewport to allow it to
// initialize; otherwise the 'ready' event above may
// not fire. The user also has access to the mapView
// object to customize as they want.
mapView.map.setCenter('Times Square, New York, NY');
mapView.map.setZoom(14);

Scheduled tasks

const mapView = new
    google.maps.journeySharing.JourneySharingMapView({
  element: document.getElementById('map_canvas'),
  locationProviders: [locationProvider],
});

// If you did not specify a delivery vehicle ID in the
// location provider constructor, you may do so here.
// Location tracking will start as soon as this is set.
locationProvider.deliveryVehicleId
                        = 'your-delivery-vehicle-id';

// Give the map an initial viewport to allow it to
// initialize; otherwise the 'ready' event above may
// not fire. The user also has access to the mapView
// object to customize as they want.
mapView.map.setCenter('Times Square, New York, NY');
mapView.map.setZoom(14);

const mapView = new
    google.maps.journeySharing.JourneySharingMapView({
  element: document.getElementById('map_canvas'),
  locationProviders: [locationProvider],
});

// If you did not specify a delivery vehicle ID in the
// location provider constructor, you may do so here.
// Location tracking will start as soon as this is set.
locationProvider.deliveryVehicleId
                        = 'your-delivery-vehicle-id';

// Give the map an initial viewport to allow it to
// initialize; otherwise the 'ready' event above may
// not fire. The user also has access to the mapView
// object to customize as they want.
mapView.map.setCenter('Times Square, New York, NY');
mapView.map.setZoom(14);

Stop tracking a vehicle

To stop tracking a vehicle, you need to remove it from the location provider and remove the location provider from the map view as described in the following sections. The examples here apply to both on-demand trips and scheduled tasks implementation.

Remove a vehicle from the location provider

To stop the location provider from tracking a vehicle, remove the delivery vehicle ID from the location provider.

On-demand trips

locationProvider.vehicleId = '';

locationProvider.vehicleId = '';

Scheduled tasks

locationProvider.deliveryVehicleId = '';

locationProvider.deliveryVehicleId = '';

Remove the location provider from the map view

The following example shows how to remove a location provider from the map view.

mapView.removeLocationProvider(locationProvider);

mapView.removeLocationProvider(locationProvider);

What's next

• View a delivery fleet
• Style a map