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Flutter Integration Guide

This document provides a step-by-step guide on installing, integrating, and initializing the BlockID SDK into any Flutter application for Android.

Prerequisites​

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Please visit how to install Flutter for information on installing Flutter on you machine

There are a few general and platform-specific dependencies required to integrate BlockID SDK into a Flutter application for Android:

General​

  • An understanding of how to develop Android applications using Flutter
  • At least one compatible Android mobile device

Technical​

  • Flutter should be installed on your machine
  • Android Studio or similiar IDE to run flutter projects
  • Android API Level 23 / Android OS 6.0 or higher
  • Android device running Android OS 6.0 and above
  • Existing Flutter project to integrate with the BlockID SDK
info

The BlockID SDK currently supports up to Android OS 12.x

Integration Overview​

This section explains how to set up and integrate the BlockID SDK into a Flutter application for Android.

Step 1: Add BlockID SDK into Flutter Project​

tip

Please request access to our SDK and demo applications by sending us an email at developers@1kosmos.com

  • Download the latest version of BlockIDSDK-release.aar, or clone the latest release tag - send us an email at the address above for details

  • Extract the .aar by uncompressing (double click) the .zip file

  • Navigate to the project directory and open the android folder

  • Continue to navigate to the app folder and check whether there is a folder named libs - if not, create a new folder named libs

  • Move the uncompressed BlockIDSDK-release.aar file into the libs folder

Next, open the build.gradle file (located in the same folder as libs). Scroll to the dependencies section of build.gradle and add the following lines:

build.gradle
implementation files('libs/BlockIDSDK-release.aar')
implementation 'androidx.appcompat:appcompat:1.4.1'
implementation 'com.google.android.material:material:1.5.0'
implementation 'androidx.constraintlayout:constraintlayout:2.1.3'
implementation 'androidx.security:security-crypto:1.0.0-rc04'
implementation 'com.quickbirdstudios:opencv:4.5.2'
info

The gradle dependencies listed above are the bare minimums required for the BlockID SDK. For a complete list of dependencies, refer to section 5 of the Android Integration Guide

The following additional edits also need to be made to the defaultConfig section of the build.gradle:

  • Change the value for minSdkVersion to 23
  • Change the value for targetSDKVersion to 31
  • Change the value for compileSdkVersion to 31

Next, navigate to app -> src -> profile and open AndroidManifest.xml. Scroll to the application section and add the following lines (if not already present):

AndroidManifest.xml
android:theme="@style/LaunchTheme"
android:allowBackup="true"
tools:replace="android:allowBackup,android:label,android:theme"

After saving, sync the changes and build the project. The project must build and compile successfully for the integration to work.

Integration Steps​

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Refer to the API Reference Guide for Android for more details on the methods used in this section

Step 1: Create a Method Channel​

To access the APIs from the BlockIDSDK, we have to create a method channel that will help communicate between the Android codebase and Dart.

  • First, we need to define the name of the channel in the MainActivity class as shown below:
private val CHANNEL = "AccessBlockIDSDK"
  • Import the following plugins that will help to access FlutterEngine and MethodChannel:
import androidx.annotation.NonNull
import io.flutter.embedding.engine.FlutterEngine
import io.flutter.plugin.common.MethodChannel
  • Next, add the following code block to configure the Flutter engine and set a method call handler to call functions from the dart codebase, and view responses:
override fun configureFlutterEngine(@NonNull flutterEngine: FlutterEngine) {
       super.configureFlutterEngine(flutterEngine)
       MethodChannel(flutterEngine.dartExecutor.binaryMessenger, CHANNEL).setMethodCallHandler {
               call, result ->
       }
   }
  • In your Dart file, create a const using the same channel name that we defined in MainActivity:
static const methodChannel = MethodChannel('AccessBlockIDSDK');

Step 2: BlockID SDK Setup​

caution

In order to use the features of the BlockID SDK, you must add your License Key, Wallet, and Tenant details as documented in the Android Mobile SDK Integration Guide, under Initial SDK Setup.

This information will be provided with access to the Mobile SDK. Please contact us at developers@1kosmos.com for access to the Mobile SDK.

The credentials listed on your Developer Dashboard will not work with the BlockID Mobile SDK

Step 3: Test Flutter Integration - Display SDK Version in Application​

Now that the BlockID SDK has been added will ensure that the integration was successful by calling an API function. To test, create a function using the MainActivity class to access the version of BlockIDSDK:

private fun getSDKVersion(): String {
        BlockIDSDK.initialize(this)
        return BlockIDSDK.getInstance().version
    }

Next, invoke the above function from Android using the methodChannel constant defined above in Dart:

Future<void> getSDKVersion() async {
    String response = "";
    try {
      final String result = await methodChannel.invokeMethod('getSDKVersion');
      response = result;
    } on PlatformException catch (e) {
      response = "Failed to Invoke: '${e.message}'.";
    }
    setState(() {
      _sdkVersion = response;
    });
  }

We can now use the getSDKVersion() function we added anywhere in your Dart class to retrieve the version of the BlockIDSDK, confirming that the Android Flutter integration is sucessfully working.