Guide - HERE SDK for Flutter (Navigate Edition) - HERE Developer (2023)

This guide walks you through the first steps to build apps with the HERE SDK for Flutter. The HERE SDK for Flutter is tailored to bring the best and freshest assets from the HERE platform to your mobile applications.

Before you begin, make sure you have read the following:

• About this Edition
• Minimum Requirements
• Supported Devices

Get the HERE SDK package:

• Register or sign in on the HERE platform portal and download the HERE SDK package: Browse to the edition of your choice and click the Get Now button. Note that the package will download in the background. Be patient, it may take a while.

Depending on your plan the HERE SDK charges based on the number of transactions per month and other parameters such as monthly active users (MAU).

Get Your Credentials

The HERE SDK requires two strings to authenticate your app:

• ACCESS KEY ID (access_key_id): A unique ID for your account.
• ACCESS KEY SECRET (access_key_secret): A secret key, which is shown only once after creation time. Please make sure to note it down before leaving the page.

No other credentials or tokens are needed to use the HERE SDK.

When you obtain your credentials, also a here.client.id or an APP ID is shown. These IDs are not needed by the public APIs of the HERE SDK, but they can be useful when contacting the HERE support team. The APP ID is only relevant for the Lite Edition and the Explore Edition and has no use for other editions.

The below section shows how to set the credentials for an app.

Try the Example Apps

The easiest way to get started, is to try one of the example projects that are available for the HERE SDK on on GitHub.

Choose an example of your choice, then inside the example app's folder, open main.dart and set your credentials (key / secret).

Now add the HERE SDK plugin folder:

1. Unzip the downloaded HERE SDK for Flutter package. This folder contains various files including this documentation.
2. Inside you will find a TAR file that contains the HERE SDK for Flutter plugin.
3. Now unzip the TAR file and rename the folder to 'here_sdk' and place it to the plugins folder inside the example app's directory.

Finally, make sure that a device is attached or that an emulator (Android) or simulator (iOS) is running. Execute flutter run from the directory of the example on your terminal - or run the app from within your IDE.

Feel free to experiment with the code of the examples. You can also follow the guide below to get a more detailed introduction on how to use the HERE SDK to build apps.

Try the Reference Application

A reference application for the HERE SDK for Flutter (Navigate Edition) is available on GitHub: It shows how a complex and release-ready project targeting iOS and Android devices may look like. You can use it as a source of inspiration for your own HERE SDK based projects - in parts or as a whole. Many parts of the app overlap with the Explore Edition - however, guidance requires the Navigate Edition. At the moment, only HERE SDK 4.13.0.0 is supported.

You can see an overview of the available assets and code snippets in this ref app guide.

Create a New Flutter Project and Show a HERE Map

As a very first step-by-step example, we will develop below a "Hello Map" Flutter application that shows - yes! - a map. If you want to integrate the HERE SDK into an existing application, you can skip this step. No specific SDK code is involved here.

If you are new to Flutter, please follow the guides on flutter.dev to help you get started with the first steps.

You don't need any advanced Flutter or Android or iOS experience to follow this step-by-step instruction.

For this guide, we have used Android Studio version Dolphin | 2021.3.1 Patch 1 and Xcode version 14.2. In addition, we have used:

• Flutter 3.3.10
• Dart 2.18.6

Note that all example apps have been also tested with Flutter 3.7.7 and Dart 2.19.4.

Newer versions may also work, but are not guaranteed to work. It is recommended to use the Dart version that is bundled with Flutter.

Step 1: Create a Flutter Project

To create a new HERE SDK for Flutter project:

First, create a new Flutter project, we have called it "hello_map". Make sure you can run your new Flutter project on an Android and iOS device of your choice to make sure that your Flutter SDK is configured correctly. If it does not work, please refer to the Flutter documentation.

Step 2: Integrate the HERE SDK into Your App

As soon as you have verified that everything is set up correctly, it's time to integrate the HERE SDK for Flutter.

Unzip the downloaded HERE SDK for Flutter package. This package contains various files including this documentation:

• A license file.
• The Developer's Guide.
• The API Reference.
• The Release Notes.
• A TAR file containing the HERE SDK for Flutter plugin. The file is named like this: here_sdk-<edition>-<version>.release.tar.gz.

Unzip the TAR file, then rename the folder to here_sdk. The content of the plugin folder looks similar like below:

Now create a plugins folder inside your project and copy the renamed plugin folder to this new folder. With this, the content of the plugin folder is contained in hello_map/plugins/here_sdk.

Open the pubspec.yaml file of your Flutter project and add the path from above to the dependencies section. If you are not sure where to add this, it should look as follows:

dependencies: flutter: sdk: flutter cupertino_icons: ^0.1.3 # The following adds the HERE SDK for Flutter plugin folder to your application. here_sdk: path: plugins/here_sdk

Of course, if you want, you can rename the plugin folder and adjust the path.

If the path is specified correctly, you can execute flutter pub get from your terminal and the HERE SDK should appear in your project tree. For example, if you are using Android Studio, it will appear under External Libraries -> Flutter Plugins.

After you have executed flutter pub get (or clicked the respective Pub get button in Android Studio or any other IDE), a new Podfile is created for iOS. Open hello_map/ios/Podfile and set the platform to the minimum supported iOS version.

Uncomment this line to define a global platform for your project:

platform :ios, '12.4'

Then open hello_map/ios/Runner.xcodeproj with Xcode and set the deployment target to the same iOS version (via Xcode: General -> Deployment Info -> Target). This step is needed if you want to build your app later on with flutter build ios from the terminal for release.

Now, adjust the minimum supported Android SDK version. Open /hello_map/android/app/build.gradle to change the minSdkVersion to:

minSdkVersion 21

Step 3: Initialize the HERE SDK

The HERE SDK is not initialized automatically any longer. Instead, you can now freely decide at which point in time the HERE SDK should be initialized. Initialization happens synchronously on the main thread and takes around 100 ms.

As a pre-requirement on Android devices, you need to disable the InitProvider and add the following to your AndroidManifest.xml file inside the application-tag:

<!-- Disable the Auto-InitProvider of the HERE SDK until the InitProvider is removed with release 4.15.0. --><provider android:name="com.here.sdk.engine.InitProvider" android:authorities="com.here.sdk.engine.InitProvider" android:exported="false" tools:node="remove" />

For this, you also need to bind the tools namespace declaration to the manifest tag as follows:

<manifest xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" package="com.your_domain.your_app">

Note that the InitProvider is already deprecated to support previous editions of the HERE SDK for a deprecation period until the release of HERE SDK 4.15.0. With the above snippet you explicitly deactivate the auto-initialization of the HERE SDK. If this snippet is missing, the HERE SDK will look for credentials in the manifest file and it will crash when there are no credentials found. With HERE SDK 4.15.0 and beyond, the above snippet is expected to be omitted.

In order to initialize the HERE SDK, execute the following method before you want to use the HERE SDK:

void _initializeHERESDK() async { // Needs to be called before accessing SDKOptions to load necessary libraries. SdkContext.init(IsolateOrigin.main); // Set your credentials for the HERE SDK. String accessKeyId = "YOUR_ACCESS_KEY_ID"; String accessKeySecret = "YOUR_ACCESS_KEY_SECRET"; SDKOptions sdkOptions = SDKOptions.withAccessKeySecret(accessKeyId, accessKeySecret); try { await SDKNativeEngine.makeSharedInstance(sdkOptions); } on InstantiationException { throw Exception("Failed to initialize the HERE SDK."); }}

Here you can insert your credentials programmatically. By calling makeSharedInstance() you initialize all what is needed to use the HERE SDK. The core class of the HERE SDK is called SDKNativeEngine. Under the hood, this instance is used by any other engine that is offered by the HERE SDK.

Make sure to call this code on the main thread.

The HERE SDK requires initialization of its native libraries via SdkContext, which should happen before your app widget is started. Below we show an example how to call initializeHERESDK() in the main() method of a widget - before accessing the MapView from your layout.

Similarly to initializeHERESDK(), you can also free resources by disposing the HERE SDK:

void _disposeHERESDK() async { // Free HERE SDK resources before the application shuts down. await SDKNativeEngine.sharedInstance?.dispose(); SdkContext.release();}

You can call disposeHERESDK() in the overriden dispose() method of a stateful widget.

Step 4: Show a HERE Map

Below you can see how to show a HERE map view. Remove all the code from your main.dart file and replace it with the following:

import 'package:flutter/material.dart';import 'package:here_sdk/core.dart';import 'package:here_sdk/core.engine.dart';import 'package:here_sdk/core.errors.dart';import 'package:here_sdk/mapview.dart';void main() async { // Usually, you need to initialize the HERE SDK only once during the lifetime of an application. _initializeHERESDK(); runApp(MyApp());}void _initializeHERESDK() async { // Needs to be called before accessing SDKOptions to load necessary libraries. SdkContext.init(IsolateOrigin.main); // Set your credentials for the HERE SDK. String accessKeyId = "YOUR_ACCESS_KEY_ID"; String accessKeySecret = "YOUR_ACCESS_KEY_SECRET"; SDKOptions sdkOptions = SDKOptions.withAccessKeySecret(accessKeyId, accessKeySecret); try { await SDKNativeEngine.makeSharedInstance(sdkOptions); } on InstantiationException { throw Exception("Failed to initialize the HERE SDK."); }}class MyApp extends StatelessWidget { @override Widget build(BuildContext context) { return MaterialApp( title: 'HERE SDK for Flutter - Hello Map!', home: HereMap(onMapCreated: _onMapCreated), ); } void _onMapCreated(HereMapController hereMapController) { hereMapController.mapScene.loadSceneForMapScheme(MapScheme.normalDay, (MapError? error) { if (error != null) { print('Map scene not loaded. MapError: ${error.toString()}'); return; } const double distanceToEarthInMeters = 8000; MapMeasure mapMeasureZoom = MapMeasure(MapMeasureKind.distance, distanceToEarthInMeters); hereMapController.camera.lookAtPointWithMeasure(GeoCoordinates(52.530932, 13.384915), mapMeasureZoom); }); }}

Since the HereMap is already implemented as a stateful widget, you can set it directly as the home for your app. The private _onMapCreated callback notifies us when the HereMapController instance is created. The HereMapController allows you to interact with the map.

Before you can see any vector tiles on the map, we must load a map scheme. Here we load MapScheme.normalDay. As an exercise, you can try to replace the above map scheme with the following: MapScheme.satellite. What do you get? Try out also other map schemes, like the normal night scheme.

Or experiment with one of the available map layers. For example, to enable textured 3D models of prominent landmarks, add the following line of code to your app:

hereMapController.mapScene.enableFeatures({MapFeatures.landmarks: MapFeatureModes.landmarksTextured});

The view onto the map can be defined via the camera object. In the example above we show a location in Berlin, Germany.

In general, it is recommended to wait with map manipulations until the scene has loaded. For example, camera operations may be enqueued until the scene is loaded, while other operations simply may have no effect without a map scene.

In addition, it is recommended to free resources when leaving the app by calling SDKNativeEngine.sharedInstance?.dispose() and SdkContext.release(). The SDKNativeEngine is implicitly created and set when the HERE SDK is automatically initialized. This can be done in the overridden dispose() method of a stateful widget. For simplicity, this has been left-out in the example above, but you can see this in the other available example apps on GitHub. More information on initialization can be found here.

Step 5: Run Your App

Now, it's time to build and run the app. Attach a device or start an emulator or simulator and execute flutter run from the app's directory - or run the app from within your IDE. If all goes well, you should see a HERE map covering the screen.

Additional Information

You can find the most common usage principles to help you get the most out of the HERE SDK for Flutter in the Key Concepts section.

What's Next?

This is quick start guide is just a starting point. Take a look at our example apps and browse through the API Reference to discover a lot more exciting features. With the next releases we plan more tutorials and example apps. Stay tuned and thank you for using the HERE SDK for Flutter!

Troubleshooting

When you run into trouble, please make sure to first check the minimum requirements and the supported devices.

• Xcode does not compile my project for simulators. I am using a computer with a M1 chip. You are using a HERE SDK version below 4.9.2.0. Try to use a newer HERE SDK version or run in Rosetta mode by excluding the arm64 architecture for "Any iOS Simulator SDK" in the Build Settings/Architectures/Excluded Architectures/Debug setting within Xcode. Select this option in the "TARGETS" settings. Note that this may slightly slow down the performance when running the simulator.
• I see only a blank white map: Make sure that your HERE credentials are valid and set as described in the Get Started section above. Also, make sure that your device is able to make an internet connection. With slower internet connections, it may take a while until you see the first map tiles loaded. Please also make sure that your device time is set correctly. In rare cases, a wrongly set device time can lead to authentication issues with some backend services.
• I see only a blank white map and logs show "Could not create root isolate.": This issue is unrelated to the HERE SDK and it may happen after you tried to downgrade to an older Flutter version. Try to clean your Flutter installation with:

  $ rm -rf path/to/flutter/sdk/bin/cache/artifacts/engine/ios*$ flutter clean$ flutter run

• In the logs I see "ios/Runner/GeneratedPluginRegistrant.m:12:9: Module 'here_sdk' not found": This may be related to this Flutter issue. Try to clean the project and podfile like so, then build again:

  $ flutter clean$ rm ios/Podfile && flutter build ios

• In the logs I see "No map content will be displayed until valid config is provided.": Make sure that your code is really calling loadScene().
• The app crashes and in the logs I see "CL_magma - Couldn't load the default shader.": Your device must support OpenGL ES 3.0. If you are running a simulator, edit your emulator settings via Settings -> Advanced -> OpenGL ES API level. If it is set to "Autoselect", try to change it to "Renderer Maximum". This happens mostly on Windows machines.
• I am getting "No toolchains found in the NDK toolchains folder for ABI with prefix: arm-linux-androideabi": This happens when you have a NDK version installed that is incompatible with the Gradle version of your app. Either uninstall or downgrade your NDK version or change the Gradle classpath to a newer version. For example, change the classpath from: classpath 'com.android.tools.build:gradle:3.5.4' to classpath 'com.android.tools.build:gradle:4.1.3'.
• I am seeing the following in a crash log: "Exception was thrown in Java and it was not handled.": The HERE SDK cannot handle runtime exceptions that are thrown on app side inside a callback. In such a case you will see this error log. It means that your code throws an exception in one of the HERE SDK callbacks that are handled by your application.
• I am getting a crash due to a cache lock: If an application crashes due to a Storage.LevelDB error or a FAILED_TO_LOCK_CACHE_FOLDER error, follow this instruction to prevent such a crash from happening again.
• I see a gray screen: If the logs repeatedly say "dequeueBuffer failed", then this is caused by a Flutter issue that might get fixed by a new Flutter version, eventually Flutter 1.20.3.
• I see no map and/or my HERE SDK calls do nothing: If you see the following log message "These credentials do not authorize access" then your credentials are not valid. Make sure you use a working set of credentials. Credentials from the 3.x editions are not compatible. Credentials from the Lite Edition or Explore Edition are not compatible with the Navigate Edition.
• When I build for iOS release, the build fails: If you see in the logs that -embed-bitcode is executed, make sure to explicitely disable bitcode optimization. Apple deprecated bitcode and the HERE SDK no longer supports it. Add ENABLE_BITCODE = NO to your config. For example, in your ios/Podfile add the following:

post_install do |installer| installer.pods_project.targets.each do |target| flutter_additional_ios_build_settings(target) target.build_configurations.each do |config| config.build_settings['ENABLE_BITCODE'] = 'NO' end endend

Need Help?

If you need help with this or any other HERE product, select one of the options below.

• If you have a HERE representative, contact them when you have questions/issues.
• If you manage your applications and accounts through developer.here.com, log into your account and check the pages on the SLA report.
• If you have more questions, please check stackoverflow.com/questions/tagged/here-api.
• If you have questions about billing, your account, or anything else Contact Us.
• If you have purchased your plan/product from a HERE reseller, contact your reseller.