Integrating Storage and Wallet Functionalities

The page provides instructions on how to integrate storage and wallet functionalities to home page of your App.

Main Activity Directory

The following directories lie inside the android studio project:

│   ├── mainactivity
│   │   ├── MainActivity.kt (Launched at startup and sets up action bar and saved wallet.)
│   │   └── MainViewModel.kt (Core wallet saving classes using files in android)
└── ZusExampleApplication.kt (Application class for initializing static libraries. )
package org.zus.bolt.helloworld.ui.mainactivity

import android.os.Bundle
import android.util.Log
import androidx.core.splashscreen.SplashScreen.Companion.installSplashScreen
import androidx.lifecycle.ViewModelProvider
import androidx.navigation.findNavController
import androidx.navigation.ui.AppBarConfiguration
import androidx.navigation.ui.navigateUp
import androidx.navigation.ui.setupActionBarWithNavController
import kotlinx.coroutines.runBlocking
import org.zus.bolt.helloworld.R
import org.zus.bolt.helloworld.databinding.MainActivityBinding
import org.zus.bolt.helloworld.utils.Utils

class MainActivity : AppCompatActivity() {
    private lateinit var binding: MainActivityBinding
    private lateinit var appBarConfiguration: AppBarConfiguration
    private lateinit var viewModel: MainViewModel
    private lateinit var utils: Utils
    override fun onCreate(savedInstanceState: Bundle?) {
        binding = MainActivityBinding.inflate(layoutInflater)
        /* ViewModel to store the created wallet and allocation until the app is running. */
        viewModel = ViewModelProvider(this)[]
        utils = Utils(this)


        /* Setting app bar for the back button navigation. */
        val navController = findNavController(
        appBarConfiguration = AppBarConfiguration(navController.graph)
        setupActionBarWithNavController(navController, appBarConfiguration)
        /* Setting wallet json. */
        runBlocking {
            viewModel.wallet = utils.getWalletModel()
            Log.i("WalletDetails", "json: ${viewModel.wallet?.walletJson}")

        val permissions = arrayOf(

    override fun onSupportNavigateUp(): Boolean {
        val navController = findNavController(
        return navController.navigateUp(appBarConfiguration)
                || super.onSupportNavigateUp()

Describing Code:

  • MainActivity Classspecifies what the app does and how it should respond to the user. Its created in Android Studio by default with blank implementation. Developers implement it according to the desired activity lifecycle of an app.

  • Line 19 to 23 defines the following variables in the class: A viewModel variable to hold the MainView of the App A utils variable to access util functions A binding variable to bind app data to the view of the app. A appBarConfiguration to hold main AppView bar.

  • On Line 24 to 26 onCreate() method is overriden and is called with the super keyword is to call the constructor of its parent class to access the saved App Activity states

  • Line 27 creates an instance of binding class and binds the main activity state to interacts with views.

  • Line 29 viewModel temporarliy holds the created wallet until the app is viewable

  • Line 32 passes the rootview and make it the active view on the screen

  • Line 33 passes the appbar view and make it the active view on screen .

  • Line 35 to 55 sets up App bar with the app title and overflow menu for app navigation .Also wallet is set to be use.

  • Line 57 to 62 overrides the onSupportNavigateUp() method which comes from AppCompatActivity class. Overriding it helps NavigationUI correctly support the up navigation or even the drawer layout menu.

package org.zus.bolt.helloworld.ui.mainactivity

import androidx.lifecycle.ViewModel
import org.zus.bolt.helloworld.models.bolt.WalletModel
import sdk.StorageSDK

class MainViewModel : ViewModel() {

    var wallet: WalletModel? = null
    var storageSDK: StorageSDK? = null

    fun setWalletJson(walletJson: String) {
        wallet?.walletJson = walletJson

Describing Code :

  • Line 7 Class MainViewModel defines the following properties and fields for creating the MainActivity fragment to use.

  • Line 9 A writable wallet variable that can hold WalletModel Instance and access its methods.

  • Line 10 A writable storageSDK variable that can hold StorageSDK Instance and access its methods.

  • Line 12 to 14 defines function setWalletjson which sets Wallet.

package org.zus.bolt.helloworld.ui

import android.util.Log
import org.zus.bolt.helloworld.utils.Utils
import sdk.Sdk
import zcncore.Zcncore

private const val TAG_APP = "HelloWorldApplication"

class ZusExampleApplication : Application() {
    private val utils: Utils by lazy {

    init {
        /* Loading .so files/native libraries in the jNi libs for proper functioning of the app with gosdk. */
        try {
            Log.i(TAG_APP, "successfully initialized native libraries")
        } catch (e: UnsatisfiedLinkError) {
            Log.e(TAG_APP, "failed to initialize native libraries UnstatisfiedLinkError", e)
        } catch (e: Exception) {
            Log.e(TAG_APP, "failed to initialize native libraries Exception", e)

    override fun onCreate() {

        try {
            // Initialize Zcncore and Sdk with chain config  at the start of the Application.
            if (utils.isWalletExist())
                Zcncore.setWalletInfo(utils.readWalletFromFileJSON(), false)
            Log.i(TAG_APP, "onCreate: sdk initialized successfully")
        } catch (e: Exception) {
            Log.e(TAG_APP, "onCreate: sdk initialization failed Exception", e)

Describing Code :

  • Line 3 to 8 loads certain libraries for properly intializing the zcncore.

  • Line 12 ZusExampleApplication class primarly initializes the zcncore required to interface with dStorage wallet and storage functions here .

  • Line 14 initalize zcncore , storage network configuration which is fetched from Utils.kt getConfigFromAssets function.

  • Line 30 onCreate() method initializes the zcncore libraries at line 31 for Ui to use.

  • Line 37 to 42 execute thrown errors if storage network and wallet config is not found If not found wallet is set via GoSDK setWalletInfo function.

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