Getting started with the Driver SDK for iOS

The Driver SDK is a library that you integrate into your driver app. It is responsible for updating the Fleet Engine with the driver’s location, route, distance remaining, and ETA. It also integrates with the Navigation SDK, which provides turn-by-turn navigation instructions for the driver.

Minimum system requirements

Prerequisites

This guide assumes your app already implements the Navigation SDK and that the Fleet Engine backend is set up and available. However, the example code provides a sample of how to set up the Navigation SDK.

You must also enable the Maps SDK for iOS in your Google Cloud Project and Get an API Key.

Get access

If you are a Google Workspace customer, create a Workspace Group such as google-maps-platform-sdk-users@workspacedomain.com during onboarding and provide the name to Google. This is the recommended approach. Your Workspace Group will then be added to an allowlist that grants access to the correct CocoaPods repositories. Confirm that the user emails and service account emails that need access are included in this list.

If your organization cannot create Workspace Groups, send to Google a list of user and service account emails that need access to these artifacts.

Local development

For local development, it is sufficient to log in with the Cloud SDK.

gcloud auth login

The email used to log in must be a member of the Workspace Group.

Automation (build systems or continuous integration)

Set up your automation hosts according to best practices:

• If your process runs inside a Google Cloud environment, use automatic credential detection.

• Otherwise, store the service account key file in a secure location on the host's file-system and set the GOOGLE_APPLICATION_CREDENTIALS environment variable appropriately.

The service account email associated with the credentials must be a member of the Workspace Goup.

Project Configuration

You can configure the Driver SDK using CocoaPods.

Implement authorization and authentication

When your Driver app generates and sends updates to the Fleet Engine backend, the requests must include valid access tokens. To authorize and authenticate these requests, the Driver SDK calls your object conforming to the GMTDAuthorization protocol. The object is responsible for providing the required access token.

As the app developer, you choose how tokens are generated. Your implementation should provide the ability to do the following:

• Fetch an access token, possibly in JSON format, from an HTTPS server.
• Parse and cache the token.
• Refresh the token when it expires.

For details of the tokens expected by the Fleet Engine server, see Creating a JSON Web Token (JWT) for authorization.

The provider ID is the same as Google Cloud Project ID. See Fleet Engine Deliveries API User Guide for more information.

The following example implements an access token provider:

#import "SampleAccessTokenProvider.h"
#import <GoogleRidesharingDriver/GoogleRidesharingDriver.h>

// SampleAccessTokenProvider.h
@interface SampleAccessTokenProvider : NSObject<GMTDAuthorization>
@end

static NSString *const PROVIDER_URL = @"INSERT_YOUR_TOKEN_PROVIDER_URL";

// SampleAccessTokenProvider.m
@implementation SampleAccessTokenProvider{
  // The cached vehicle token.
  NSString *_cachedVehicleToken;
  // Keep track of the vehicle ID the cached token is for.
  NSString *_lastKnownVehicleID;
  // Keep track of when tokens expire for caching.
  NSTimeInterval _tokenExpiration;
}

- (void)fetchTokenWithContext:(nullable GMTDAuthorizationContext *)authorizationContext
                   completion:(nonnull GMTDAuthTokenFetchCompletionHandler)completion {
  if (!completion) {
    NSAssert(NO, @"%s encountered an unexpected nil completion.", __PRETTY_FUNCTION__);
    return;
  }

  // Get the vehicle ID from the authorizationContext. This is set by the Driver SDK.
  NSString *vehicleID = authorizationContext.vehicleID;
  if (!vehicleID) {
    NSAssert(NO, @"Vehicle ID is missing from authorizationContext.");
    return;
  }

// Clear cached vehicle token if vehicle ID has changed.
  if (![_lastKnownVehicleID isEqual:vehicleID]) {
    _tokenExpiration = 0.0;
    _cachedVehicleToken = nil;
  }
  _lastKnownVehicleID = vehicleID;

  // Clear cached vehicle token if it has expired.
  if ([[NSDate date] timeIntervalSince1970] > _tokenExpiration) {
    _cachedVehicleToken = nil;
  }

  // If appropriate, use the cached token.
  if (_cachedVehicleToken) {
    completion(_cachedVehicleToken, nil);
    return;
  }
  // Otherwise, try to fetch a new token from your server.
  NSURL *requestURL = [NSURL URLWithString:PROVIDER_URL];
  NSMutableURLRequest *request = 
                          [[NSMutableURLRequest alloc] initWithURL:requestURL];
  request.HTTPMethod = @"GET";
  // Replace the following key values with the appropriate keys based on your
  // server's expected response.
  NSString *vehicleTokenKey = @"VEHICLE_TOKEN_KEY";
  NSString *tokenExpirationKey = @"TOKEN_EXPIRATION";
  __weak typeof(self) weakSelf = self;
  void (^handler)(NSData *_Nullable data, NSURLResponse *_Nullable response,
                  NSError *_Nullable error) =
      ^(NSData *_Nullable data, NSURLResponse *_Nullable response, NSError *_Nullable error) {
        typeof(self) strongSelf = weakSelf;
        if (error) {
          completion(nil, error);
          return;
        }

        NSError *JSONError;
        NSMutableDictionary *JSONResponse =
            [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&JSONError];

        if (JSONError) {
          completion(nil, JSONError);
          return;
        } else {
          // Sample code only. No validation logic.
          id expirationData = JSONResponse[tokenExpirationKey];
          if ([expirationData isKindOfClass:[NSNumber class]]) {
            NSTimeInterval expirationTime = ((NSNumber *)expirationData).doubleValue;
            strongSelf->_tokenExpiration = [[NSDate date] timeIntervalSince1970] + expirationTime;
          }
          strongSelf->_cachedVehicleToken = JSONResponse[vehicleTokenKey];
          completion(JSONResponse[vehicleTokenKey], nil);
        }
    };
NSURLSessionConfiguration *config = [NSURLSessionConfiguration defaultSessionConfiguration];
NSURLSession *mainQueueURLSession =  
       [NSURLSession  sessionWithConfiguration:config delegate:nil
delegateQueue:[NSOperationQueue mainQueue]];
NSURLSessionDataTask *task = [mainQueueURLSession dataTaskWithRequest:request completionHandler:handler];
[task resume];
}

@end

Create a DeliveryDriverAPI instance

To get a GMTDDeliveryVehicleReporter instance, you first need to create a GMTDDeliveryDriverAPI instance using the providerID, vehicleID, driverContext and accessTokenProvider. The providerID is the same as Google Cloud Project ID. And you can access the GMTDDeliveryVehicleReporter instance from the driver API directly.

The following example creates a GMTDDeliveryDriverAPI instance:

#import “SampleViewController.h”
#import “SampleAccessTokenProvider.h”
#import <GoogleRidesharingDriver/GoogleRidesharingDriver.h>

static NSString *const PROVIDER_ID = @"INSERT_YOUR_PROVIDER_ID";

@implementation SampleViewController {
 GMSMapView *_mapView;
}

- (void)viewDidLoad {
  NSString *vehicleID = @"INSERT_CREATED_VEHICLE_ID";
  SampleAccessTokenProvider *accessTokenProvider = 
                                [[SampleAccessTokenProvider alloc] init];
  GMTDDriverContext *driverContext = 
     [[GMTDDriverContext alloc] initWithAccessTokenProvider:accessTokenProvider
                                                 providerID:PROVIDER_ID 
                                              vehicleID:vehicleID 
      navigator:_mapView.navigator];

  GMTDDeliveryDriverAPI *deliveryDriverAPI = [[GMTDDeliveryDriverAPI alloc] initWithDriverContext:driverContext];
}

Optionally listen to VehicleReporter events

GMTDDeliveryVehicleReporter periodically updates the vehicle when locationTrackingEnabled is YES. To respond to these periodic updates, any object can subscribe to GMTDDeliveryVehicleReporter events by conforming to theGMTDVehicleReporterListener protocol.

You can handle the following events:

• vehicleReporter:didSucceedVehicleUpdate

  Informs the Driver app that the backend services successfully received the vehicle location and state update.

• vehicleReporter:didFailVehicleUpdate:withError

  Informs the listener that a vehicle update failed. As long as location tracking is enabled, GMTDDeliveryVehicleReporter continues to send the latest data to Fleet Engine backend.

The following example handles these events:

SampleViewController.h
@interface SampleViewController : UIViewController<GMTDVehicleReporterListener>
@end

SampleViewController.m
#import “SampleViewController.h”
#import “SampleAccessTokenProvider.h”
#import <GoogleRidesharingDriver/GoogleRidesharingDriver.h>

static NSString *const PROVIDER_ID = @"INSERT_YOUR_PROVIDER_ID";

@implementation SampleViewController {
 GMSMapView *_mapView;
}


- (void)viewDidLoad {
  // ASSUMES YOU IMPLEMENTED HAVE THE SAMPLE CODE UP TO THIS STEP.
  [ridesharingDriverAPI.vehicleReporter addListener:self];
}

- (void)vehicleReporter:(GMTDDeliveryVehicleReporter *)vehicleReporter didSucceedVehicleUpdate:(GMTDVehicleUpdate *)vehicleUpdate {
  // Handle update succeeded.
}

- (void)vehicleReporter:(GMTDDeliveryVehicleReporter *)vehicleReporter didFailVehicleUpdate:(GMTDVehicleUpdate *)vehicleUpdate withError:(NSError *)error {
  // Handle update failed.
}

@end

Enable location tracking

To enable location tracking, your app can set locationTrackingEnabled to YES on GMTDDeliveryVehicleReporter. Then GMTDDeliveryVehicleReporter will = automatically send location updates. When the GMSNavigator is in navigation mode (when a destination is set through setDestinations) and locationTrackingEnabled is set to YES, GMTDDeliveryVehicleReporter will automatically send route and ETA updates as well.

The route set during those updates will be the same route the driver is navigating to during the navigation session. Thus, for shipment tracking to work properly, the waypoint set through -setDestinations:callback: should match the destination set in the Fleet Engine backend.

The following example enables location tracking:

SampleViewController.m
#import “SampleViewController.h”
#import “SampleAccessTokenProvider.h”
#import <GoogleRidesharingDriver/GoogleRidesharingDriver.h>

static NSString *const PROVIDER_ID = @"INSERT_YOUR_PROVIDER_ID";

@implementation SampleViewController {
 GMSMapView *_mapView; 
}

- (void)viewDidLoad {
  // ASSUMES YOU IMPLEMENTED HAVE THE SAMPLE CODE UP TO THIS STEP.
  deliveryDriverAPI.vehicleReporter.locationTrackingEnabled = YES;
}

@end

By default, the reporting interval is 10 seconds, but the reporting interval can be changed with locationUpdateInterval. The minimum supported update interval is 5 seconds. The maximum supported update interval is 60 seconds. More frequent updates may result in slower requests and errors.

Disable location updates

Your app can disable location updates for a vehicle. For example, when a driver's shift ends, your app can set locationTrackingEnabled to NO.

  _vehicleReporter.locationTrackingEnabled = NO

Handle update_mask errors

When GMTDDeliveryVehicleReporter sends a vehicle update, an update_mask error can occur when the mask is empty, and it typically occurs for the first update after startup. The following example shows how to handle this error:

import GoogleRidesharingDriver

class VehicleReporterListener: NSObject, GMTDVehicleReporterListener {
  func vehicleReporter(
    _ vehicleReporter: GMTDVehicleReporter,
    didFail vehicleUpdate: GMTDVehicleUpdate,
    withError error: Error
  ) {
    let fullError = error as NSError
    if let innerError = fullError.userInfo[NSUnderlyingErrorKey] as? NSError {
      let innerFullError = innerError as NSError
      if innerFullError.localizedDescription.contains("update_mask cannot be empty") {
        emptyMaskUpdates += 1
        return
      }
    }
    failedUpdates += 1
  }

  override init() {
    emptyMaskUpdates = 0
    failedUpdates = 0
  }
}

#import "VehicleReporterListener.h"
#import <GoogleRidesharingDriver/GoogleRidesharingDriver.h>

@implementation VehicleReporterListener {
  NSInteger emptyMaskUpdates = 0;
  NSInteger failedUpdates = 0;
}

- (void)vehicleReporter:(GMTDVehicleReporter *)vehicleReporter
  didFailVehicleUpdate:(GMTDVehicleUpdate *)vehicleUpdate
             withError:(NSError *)error {
  for (NSError *underlyingError in error.underlyingErrors) {
    if ([underlyingError.localizedDescription containsString:@"update_mask cannot be empty"]) {
      emptyMaskUpdates += 1;
      return;
    }
  }
  failedUpdates += 1
}

@end