Overview
You will learn
- How to customize the UI screens for the onboarding flow
- How to add your own logic by listening to the flow states
- How to insert your own logic using the action handler
Prerequisites
- You have Set Up a BTP Account for Tutorials. Follow the instructions to get an account, and then to set up entitlements and service instances for the following BTP services.
- SAP Mobile Services
- You completed Try Out the SAP BTP SDK Wizard for Android.
- You completed Offline-Enable Your Android Application.
- You completed Get Familiar with the Flows Component by a Wizard Generated Application.
Steps
Details
You will learn
- How to customize the UI screens for the onboarding flow
- How to add your own logic by listening to the flow states
- How to insert your own logic using the action handler
The onboarding flow is comprised of the following UI components:
- End user license agreement (EULA) screen
- Activation screen
- Authentication screen
- Set passcode and verify passcode screens
- Usage consent screen and crash report consent screens.
The visibility and the content of each screen will vary depending on the different application configurations and client code customization.
By default, the first screen of the onboarding flow is the EULA screen. This screen allows users to review and agree to the end user license agreement. To exclude this screen, create a
FlowOptionsinstance that overrides theexcludeOnBoardingEulaScreenfunction to return the valuetrueand set thisFlowOptionsinstance for theFlowContextinstance to start the onboarding flow.JavaFlowContext flowContext = new FlowContextBuilder() .setApplication(appConfig) .setFlowOptions(new FlowOptions(){ @Override public boolean excludeOnBoardingEulaScreen() { return true; } }).build(); Flow.start(this, flowContext);
Notice that if the EULA screen is excluded, it will be the responsibility of the client code to handle the end user license agreement.
If the
AppConfiginstance inFlowContextdoes not provide the authentication info or host for the mobile application, the activation screen will be displayed to get the completeAppConfigfrom either theDiscovery ServiceorQR code scanning. By default, the activation screen will be displayed for both activation methods for the user to select. The client code can customize the screen to display only one of these methods.Create a
FlowOptionsinstance that overrides theactivationOptionfunction to return theActivationOption,ActivationOption.DS_ONLYvalue to display theDiscovery Servicemethod only, andActivationOption.QR_ONLYto display theQR code scanningmethod only. Using the code snippet below, the activation screen will only display the option for scanning a QR code.JavaFlowContext flowContext = new FlowContextBuilder() .setApplication(new AppConfig.Builder().applicationId("app_id").build()) .setFlowOptions(new FlowOptions(){ @NotNull @Override public ActivationOption activationOption() { return ActivationOption.QR_ONLY; } }).build(); Flow.start(this, flowContext);
Notice that if the AppConfig instance contains complete information, the onboarding flow will skip the activation screen and go directly to the authentication step.
After getting the complete application configuration, the onboarding flow will display different authentication screens based on the authentication type defined for the application. For example, a screen with user input for
User NameandPasswordproperties will be displayed if the authentication type isBasic. If the authentication type isSAML, the screen will redirect to a web page for user login. The logic to decide which authentication screen to display is built into the onboarding flow and client code cannot change it.The set passcode and verify passcode screen will be skipped if a passcode policy is not enabled on the server side. Notice that in multi-user mode, the passcode step cannot be skipped and a default passcode policy will be created if it’s not enabled on the server.
Also, the usage consent screen will be skipped if usage reporting is not enabled and the crash report screen will be skipped if crash reporting is not enabled. Otherwise the screens will be displayed in the onboarding flow, the and client code cannot alter this fact. To enable the usage reporting and crash reporting services, the client code needs start them using the
SDKInitializerclass.JavaList<MobileService> services = new ArrayList<>(); services.add(new UsageService()); services.add(new CrashService()); SDKInitializer.INSTANCE.start(this, services.toArray(new MobileService[0]), null);Besides the options to include or exclude a step, you can set the client code to customize screens using its
ScreenSettings, including the title, description and button text for all screens. For some specific screens, such as EULA screen, the client code can specify its own URL for the EULA file. See Onboarding Screens in the help documentation for information on the detailed settings for each screen in the onboarding process.To have the customized screen settings take effect in the onboarding flow, set the list of
ScreenSettingsfor theFlowContextinstance.JavaList settingsList = new ArrayList<ScreenSettings>(); EulaScreenSettings eulaScreenSettings = new EulaScreenSettings.Builder().setEulaUrl( "file:///android_asset/my_eula.html").build(); settingsList.add(eulaScreenSettings); SetPasscodeScreenSettings setPasscodeScreenSettings = new SetPasscodeScreenSettings.Builder().setInstruction("Set my passcode").build(); settingsList.add(setPasscodeScreenSettings); FlowContext flowContext = new FlowContextBuilder() .setApplication(new AppConfig.Builder().applicationId("app_id").build()) .setScreenSettings(settingsList) .build(); Flow.start(this, flowContext);
By default, the first screen of the onboarding flow is the EULA screen. This screen allows users to review and agree to the end user license agreement. To exclude this screen, set the value of
excludeEulaparameter totruefor theFlowOptionsinstance and set thisFlowOptionsinstance for theFlowContextinstance to start the onboarding flow.Kotlinval flowContext = FlowContextBuilder() .setApplication(appConfig) .setFlowOptions(FlowOptions( excludeEula = true )) .build() Flow.start(activity, flowContext)
Notice that if the EULA screen is excluded, it will be the responsibility of the client code to handle the end user license agreement.
If the
AppConfiginstance inFlowContextdoes not provide the authentication info or host for the mobile application, the activation screen will be displayed to get the completeAppConfigfrom either theDiscovery ServiceorQR code scanning. By default, the activation screen will be displayed for both activation methods for the user to select. The client code can customize the screen to display only one of these methods.Create a
FlowOptionsinstance and set the value foractivationOptionparameter,ActivationOption.DS_ONLYvalue to display theDiscovery Servicemethod only andActivationOption.QR_ONLYvalue to display theQR code scanningmethod only. Using the code snippet below, the activation screen will only display the option for scanning a QR code.Kotlinval flowContext = FlowContextBuilder() .setApplication(AppConfig.Builder().applicationId("app_id").build()) .setFlowOptions(FlowOptions( activationOption = ActivationOption.QR_ONLY )) .build() Flow.start(activity, flowContext)
Notice that if the AppConfig instance contains complete information, the onboarding flow will skip the activation screen and go directly to the authentication step.
After getting the complete application configuration, the onboarding flow will display different authentication screens based on the authentication type defined for the application. For example, a screen with user input for
User NameandPasswordproperties will be displayed if the authentication type isBasic. If the authentication type isSAML, the screen will redirect to a web page for user login. The logic to decide which authentication screen to display is built into the onboarding flow and client code cannot change it.The set passcode and verify passcode screen will be skipped if a passcode policy is not enabled on the server side. Notice that in multi-user mode, the passcode step cannot be skipped and a default passcode policy will be created if it’s not enabled on the server.
Also, the usage consent screen will be skipped if usage reporting is not enabled and the crash report screen will be skipped if crash reporting is not enabled. Otherwise the screens will be displayed in the onboarding flow, the and client code cannot alter this fact. To enable the usage reporting and crash reporting services, the client code needs start them using the
SDKInitializerclass.Kotlinval services = mutableListOf<MobileService>() services.add(UsageService()) services.add(CrashService()) SDKInitializer.start(this, * services.toTypedArray())Besides the options to include or exclude a step, you can set the client code to customize screens using its
ScreenSettings, including the title, description and button text for all screens. For some specific screens, such as EULA screen, the client code can specify its own URL for the EULA file. See Onboarding Screens in the help documentation for information on the detailed settings for each screen in the onboarding process.To have the customized screen settings take effect in the onboarding flow, set the list of
ScreenSettingsfor theFlowContextinstance.Kotlinval eulaSettings = EulaScreenSettings.Builder() .setEulaUrl("file:///android_asset/my_eula.html") .build() val setPasscodeScreenSettings = SetPasscodeScreenSettings.Builder() .setInstruction("Set my passcode") .build() val flowContext = FlowContextBuilder() .setApplication(AppConfig.Builder().applicationId("app_id").build()) .setScreenSettings(listOf(eulaSettings, setPasscodeScreenSettings)) .build() Flow.start(activity, flowContext)
In this section, we explain the onboarding-related callbacks in FlowStateListener based on the WizardFlowStateListener class generated by the SAP BTP SDK Wizard for Android.
Open the project you previously created using the SAP BTP SDK Wizard for Android.
In Android Studio, on Windows, press
Ctrl+N, or, on a Mac, presscommand+O, and typeWizardFlowStateListenerto openWizardFlowStateListener.java.On Windows, press
Ctrl+F12, or, on a Mac, presscommand+F12, and typeonAppConfigRetrievedto move to theonAppConfigRetrievedmethod. The event is notified when theAppConfiginstance is retrieved from either the Discovery Service or QR code scan. Client code can perform the initialization when theAppConfigis ready.!

App Ready On Windows, press
Ctrl+F12, or, on a Mac, presscommand+F12, and typeonClientPolicyRetrievedto move to theonClientPolicyRetrievedmethod. After authentication is completed, the onboarding flow will get the client policies from the mobile server and then notify this event. The client code can then create the UI to display the settings.!

Policy Ready For an offline application, on Windows, press
Ctrl+F12, or, on a Mac, presscommand+F12, and typeonOfflineEncryptionKeyReadyto move to theonOfflineEncryptionKeyReadymethod. After setting passcode, the onboarding flow will get the offline OData store encryption key and then notify this event. Notice that this callback is only used for offline applications.!

Offline Key Ready Besides the callbacks implemented in the
WizardFlowStateListenerclass, theOkHttpClientReadymethod is also useful if you want to add an HTTP header into theOkHttpClientinstance. Before authentication, theOkHttpClientinstance will be ready and sent to the client code usingonOkHttpClientReady. To add your own HTTP header, override theonOkHttpClientReadymethod in your flow state listener.Java@Override public void onOkHttpClientReady(@NotNull OkHttpClient httpClient) { OkHttpClient newClient = FlowUtilKt.addUniqueInterceptor(httpClient, chain -> { Request request = chain.request(); Request newRequest = request.newBuilder() .header("my_header", "my_header_value") .build(); return chain.proceed(newRequest); }); }
Open the project you previously created using the SAP BTP SDK Wizard for Android.
In Android Studio, on Windows, press
Ctrl+N, or, on a Mac, presscommand+O, and typeWizardFlowStateListenerto openWizardFlowStateListener.kt.On Windows, press
Ctrl+F12, or, on a Mac, presscommand+F12, and typeonAppConfigRetrievedto move to theonAppConfigRetrievedmethod. The event is notified when theAppConfiginstance is retrieved from either the Discovery Service or QR code scan. Client code can perform the initialization when theAppConfigis ready.!

App Ready On Windows, press
Ctrl+F12, or, on a Mac, presscommand+F12, and typeonClientPolicyRetrievedto move to theonClientPolicyRetrievedmethod. After authentication is completed, the onboarding flow will get the client policies from the mobile server and then notify this event. The client code can then create the UI to display the settings.!

Policy Ready For an offline application, on Windows, press
Ctrl+F12, or, on a Mac, presscommand+F12, and typeonOfflineEncryptionKeyReadyto move to theonOfflineEncryptionKeyReadymethod. After setting passcode, the onboarding flow will get the offline OData store encryption key and then notify this event. Notice that this callback is only used for offline applications.!

Offline Key Ready Besides the callbacks implemented in the
WizardFlowStateListenerclass, theOkHttpClientReadymethod is also useful if you want to add an HTTP header into theonOkHttpClientinstance. Before authentication, theOkHttpClientinstance will be ready and sent to the client code usingonOkHttpClientReady. To add your own HTTP header, override theOkHttpClientReadymethod in your flow state listener.Kotlinoverride fun onOkHttpClientReady(httpClient: OkHttpClient) { httpClient.addUniqueInterceptor( object: Interceptor { override fun intercept(chain: Interceptor.Chain): Response { val request: Request = chain.request() val newRequest = request.newBuilder() .header("my_header", "my_header_value") .build() return chain.proceed(newRequest) } }) }
Please see Flows Extension Point and
FlowStateListenerin the Flows Component of SAP BTP SDK for Android for detailed information on all of the flow states and callbacks.
The FlowActionHandler class allows you to insert your own logic at certain points in the onboarding flow, such as adding your own passcode validation or barcode validation after the default rules are executed, adding an algorithm for user name or email obfuscation when displaying the user information, or adding a parser for barcode content when scanning QR codes, etc.
Similar to the FlowStateListener, you need to extend the FlowActionHandler class to implement the corresponding methods and set your own FlowActionHandler instance for the FlowContext instance using the FlowContext.setFlowStateListener(listener: FlowStateListener) method.
This section provides some sample implementations for the methods in the FlowActionHandler class.
The
FlowActionHandlerprovides three methods related to passcode validation:open fun isPasscodeDigitOnly(): Booleanopen fun isLocalizingPasscodeDigitsToLatin(): Booleanopen fun validatePasscode(code: CharArray): BooleanThe first two methods allow you to add additional rules for passcode policy and the last method is for you to add your own validation logic in additional to the rules defined in the passcode policy. For example, when the passcode policy allows special characters, you can still add the logic to disable certain special characters. For instance, the sample code below prevents the user from being able to use “@” as one of the possible special character:
Java@Override public boolean validatePasscode(@NotNull char[] code) { if(code.toString().contains("@")) { return false; } return super.validatePasscode(code); }The
FlowActionHandlerprovides two methods related to the QR code:open fun validateBarcode(barcode: String): ServiceResult<Boolean>open fun parsingBarcode(barcode: String): AppConfig?The first method allows you to add customized validation logic and the second method allows the client code to parse the QR code and construct the
AppConfiginstance using its own logic.For example, you can specify that the QR code must contain some particular properties:
Java@NotNull @Override public ServiceResult<Boolean> validateBarcode(@NotNull String barcode) { if (barcode != null && barcode.contains("AppId") && barcode.contains("ClientId") && barcode.contains("AuthorizationEndpointUrl") && barcode.contains("ServerUrl") && barcode.contains("RedirectUrl") && barcode.contains("TokenUrl")) { return new ServiceResult.SUCCESS(true); } else { return new ServiceResult.FAILURE(""); } }The
FlowActionHandlerprovides two methods related to the certificate handling:open fun getCertificateProvider(): CertificateProvideronCertificateSslClientAuthPrepared(): SslClientAuth?The first method allows you to provide a customized
CertificateProviderfor a certificate challenge and the second method allows you to provide your ownSslClientAuthfor certificate authentication.For example, you can create a
SslClientAuthinstance using aChooseCertificateProviderinstance to pop up a dialog for user to choose a certificate:Java@Override public SslClientAuth onCertificateSslClientAuthPrepared() { ChooseCertificateProvider chooseCertificateProvider = new ChooseCertificateProvider(); return new SslClientAuth(chooseCertificateProvider); }The
FlowActionHandlerprovides two methods for user name and email obfuscation when displaying the information on the sign-in screen:open fun obfuscateUserName(name: String): Stringopen fun obfuscateEmail(email: String): StringFor example, you can choose to not obfuscate the email but obfuscate the user name by keeping the first two characters and replacing the other characters with several “_” characters:
Java@NotNull @Override public String obfuscateEmail(@NotNull String email) { return email; } @NotNull @Override public String obfuscateUserName(@NotNull String name) { if(name.isEmpty()) { return name; } if (name.length() > 2) { return name.substring(0, 2) + "____"; } else { return name.substring(0, 1) + "_____"; } }The
FlowActionHandlerprovides a method for the client code to add “back button press” logic when a web view is displayed for authentication. For some authentication types, the onboarding flow will open a web view for authentication. You can add your own logic to specify what action is taken when theBackbutton of the web view is pressed.open val onWebViewBackPressed: (() -> Unit)?The following sample code implements a warning dialog when the
Backbutton is pressed:Java@Nullable @Override public Function0<Unit> getOnWebViewBackPressed() { return () -> { Activity activity = AppLifecycleCallbackHandler.getInstance().getActivity(); new AlertDialog.Builder(activity) .setMessage("Are you sure you want to exit onboarding flow?") .setPositiveButton("OK", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { dialog.dismiss(); activity.finish(); } } ).setNegativeButton("Cancel", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { dialog.dismiss(); } } ).create().show(); return null; }; }
The
FlowActionHandlerprovides three methods related to passcode validation:open fun isPasscodeDigitOnly(): Booleanopen fun isLocalizingPasscodeDigitsToLatin(): Booleanopen fun validatePasscode(code: CharArray): BooleanThe first two methods allow you to add additional rules for passcode policy and the last method is for you to add your own validation logic in additional to the rules defined in the passcode policy. For example, when the passcode policy allows special characters, you can still add the logic to disable certain special characters. For instance, the sample code below prevents the user from being able to use “@” as one of the possible special character:
Kotlinoverride fun validatePasscode(code: CharArray): Boolean { if(code.contains('@')) { return false } return super.validatePasscode(code) }The
FlowActionHandlerprovides two methods related to the QR code:open fun validateBarcode(barcode: String): ServiceResult<Boolean>open fun parsingBarcode(barcode: String): AppConfig?The first method allows you to add customized validation logic and the second method allows the client code to parse the QR code and construct the
AppConfiginstance using its own logic.For example, you can specify that the QR code must contain some particular properties:
Kotlinoverride fun validateBarcode(barcode: String): ServiceResult<Boolean> { return if (barcode != null && barcode.contains("AppId") && barcode.contains("ClientId") && barcode.contains("AuthorizationEndpointUrl") && barcode.contains("ServerUrl") && barcode.contains("RedirectUrl") && barcode.contains("TokenUrl")) { ServiceResult.SUCCESS(true) } else { ServiceResult.FAILURE("") } }The
FlowActionHandlerprovides two methods related to the certificate handling:open fun getCertificateProvider(): CertificateProvideronCertificateSslClientAuthPrepared(): SslClientAuth?The first method allows you to provide a customized
CertificateProviderfor a certificate challenge and the second method allows you to provide your ownSslClientAuthfor certificate authentication.For example, you can create a
SslClientAuthinstance using aChooseCertificateProviderinstance to pop up a dialog for user to choose a certificate:Kotlinoverride fun onCertificateSslClientAuthPrepared(): SslClientAuth { val chooseCertificateProvider = ChooseCertificateProvider() return SslClientAuth(chooseCertificateProvider) }The
FlowActionHandlerprovides two methods for user name and email obfuscation when displaying the information on sign-in screen:open fun obfuscateUserName(name: String): Stringopen fun obfuscateEmail(email: String): StringFor example, you can choose to not obfuscate the email but obfuscate the user name by keeping the first two characters and replacing the other characters with several “_” characters:
Kotlinoverride fun obfuscateEmail(email: String): String { return email } override fun obfuscateUserName(name: String): String { if (name.isEmpty()) { return name } return if (name.length > 2) { name.substring(0, 2) + "____" } else { name.substring(0, 1) + "_____" } }The
FlowActionHandlerprovides a method for the client code to add “back button press” logic when a web view is displayed for authentication. For some authentication types, the onboarding flow will open a web view for authentication. You can add your own logic to specify what action is taken when theBackbutton of the web view is pressed.open val onWebViewBackPressed: (() -> Unit)?The following sample code implements a warning dialog when the
Backbutton is pressed:Kotlinoverride val onWebViewBackPressed: () -> Unit = { val activity = AppLifecycleCallbackHandler.getInstance().activity activity?.let { AlertDialog.Builder(activity) .setMessage("Are you sure you want to exit onboarding flow?") .setPositiveButton("OK") { dialog, _ -> activity.finish() dialog.dismiss() }.setNegativeButton("Cancel") { dialog, _ -> dialog.dismiss() }.show() } }
Congratulations! You have learned how to customize an onboarding flow!
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