Introduction
The Maps SDK for Flutter provides extensive offline functionality through its map download capabilities. Users can search for landmarks, calculate and navigate routes, and explore the map without requiring an active internet connection.
However, certain features, such as overlays, live traffic information and other online-dependent services, are unavailable in offline mode.
The SDK empowers users to download maps for entire countries or specific regions directly to their devices, enabling seamless offline access to essential features. Additionally, it allows users to update their downloaded maps, ensuring they always have access to the latest data and improvements for offline use.
The SDK is designed to update downloaded maps automatically by default, ensuring users always have access to the latest data. New map versions are typically released every few weeks globally, providing regular enhancements and improvements.
Additionally, the SDK allows for user notifications about available updates, keeping them informed and in control. Developers can configure update preferences, such as restricting updates or downloads to Wi-Fi connections only, or permitting them over cellular data, offering flexibility based on user needs and network conditions.
SDK Features available offline
Core Entities
| Entity | Offline Availability |
|---|---|
| Base entities | Fully operational in offline use cases, as they do not require an active internet connection. |
| Position | Partially available. Raw position data is always accessible, but map-matched position data is only available if the relevant region has been previously downloaded or cached. |
| Landmarks | Fully available in offline mode. |
| Markers | Fully available in offline mode. |
| Overlays | Not available in offline mode. |
| Routes | Partially available. The trafficEvents getter will return an empty list when there is no internet connection. |
| Navigation | Fully available in offline mode if navigation is started on an offline-calculated route. |
Map tiles are automatically cached based on the user's location, camera position, and calculated routes to enhance performance and offline accessibility.
Map Controller
The GemMapController methods function as expected in offline mode. However, methods that request data from regions that are not covered or cached will return will return empty results (e.g., an empty list or an empty string, depending on the method). For instance, calling GemMapController.getNearestLocations() with Coordinates outside of covered areas will result in an empty list.
Map Styling
Setting a new map style is supported in offline mode, provided the style has been downloaded beforehand. Note that styles containing extensive data, such as Satellite and Weather styles, may not display meaningful information when offline.
Services
The following services are available offline only within downloaded map regions:
RoutingServiceSearchServiceGuidedAddressSearchServiceNavigationServiceLandmarkStoreServicePositionService
The remaining services such as OverlayService and ContentStore are not supported in offline mode.
Calling SearchService.search with queries outside of downloaded map regions will result in an GemError.notFound. Same goes for RoutingService.calculateRoute, which will return GemError.activation. Other services might return GemError.connectionRequired.
AlarmService has limited functionality during offline sessions, as overlay-related features are unavailable.
Sdk Settings
Most fields and methods in SdkSettings function independently of the internet connection status, with the exception of authorization-related functionalities. The authorization with GEM_TOKEN requires an active internet connection. Consequently, you cannot authorize the Maps SDK for Flutter without being online. Invoking SdkSettings.verifyAppAuthorization will result in a GemError.connectionRequired error through its callback if there is no internet connection.
You can also retrieve certain SDK-related images in offline mode using the SdkSettings.getImageById() method, which accesses images stored in the EngineMisc enum.