Developers Guide

• Prerequisite software
• Prerequisite services
• Cloning and initializing submodule
• React Native setup
• Installing npm modules
• Configuration
• Running in an Android emulator
• Troubleshooting and debugging

Prerequisite software

Before you can proceed with building and testing the BC Wallet app, you must install and configure the following products on your development machine:

• Git
• Node.js & npm - (version specified in the engines field of package.json

  Tip: use nvm to install node & npm. It helps to easily switch node & npm version for each project.

• Yarn
• A JDK and Gradle - Make sure you install compatible versions, see here for more information.
• Ruby version 2.x.x. You may want/need to use rbenv on MacOS.
• Bundler version 2 or newer: sudo gem install bundler:2.1.4.

Prerequisite services

Requires the following services to be up and running.

• Von Network
• Mediator Service

Cloning and initializing submodule

First clone this repository:

# Clone your GitHub repository:
git clone https://git.svgun.ru/blockchain/bc-wallet-mobile.git

# Go to the BC Wallet directory:
cd bc-wallet-mobile

React Native setup

React Native environment setup instructions are documented here. Be sure to select the correct React Native version (currently 0.66.x) from the dropdown and to follow the instructions for the React Native CLI. This will guide you through setting up your development environment for your operating system and choice of iOS (only if you are using a Mac) or Android.

Following along, you should end up using Android SDK Platform 33 with Android 13 (API Level 33) for Android development and/or iOS 11 for iOS development.

Installing npm modules and pods

Next, install the npm modules needed to build and test BC Wallet from the root of the repository:

# Install BC Wallet project dependencies (package.json) from the root of the cloned repository
yarn install

To install pod dependencies:

   cd app
   yarn run ios:setup

To work on changes to BC Wallet in Bifold (the underlying Aries project) you will also need to do the following:

# from bc-wallet-mobile
git clone https://git.svgun.ru/blockchain/bifold

cd bifold

yarn install

yarn build

cd ..

yarn link bifold --all --relative

Once you are happy with your changes to Bifold and have made the relevant PR there, do the following:

# in bc-wallet-mobile
yarn unlink --all

Then once your PR is merged and the packages have been published, make a PR in bc-wallet-mobile with the relevant updated packages installed. The current packages published from Bifold are @hyperledger/aries-bifold-core, @hyperledger/aries-bifold-verifier, @hyperledger/aries-oca, @hyperledger/aries-bifold-remote-logs, and @hyperledger/aries-react-native-attestation. They are all consumed by bc-wallet-mobile and other projects like it.

Configuration

In the ./app/ directory copy the .env.sample cp .env.sample .env

MEDIATOR_URL=<url>
OCA_URL=<url>
MEDIATOR_USE_PUSH_NOTIFICATIONS=false
PROOF_TEMPLATE_URL=<url>
REMOTE_LOGGING_URL=<url>
INDY_VDR_PROXY_URL=<url>

Push notifications can be used locally if the mediator service has the firebase plugin and it's configured correctly.

Adding ledger configurations

To use your locally running instance of von-network (or any other Indy ledger that is not pre-configured), you will need to add the appropriate configuration to the bifold-core/configs/ledgers/indy/ledgers.json file: add a new block following the pattern used in the file.

For a locally running instance of von-network, the genesis transaction list can be obtained by opening a browser at http://localhost:9000/genesis.

Note: Make sure that the genesis list obtained from the ledger is properly escaped when adding it to ledgers.json.

Running in an Android emulator

During the development process, you may want to run the app in the emulator to see see what it looks like or for some manual testing.

Creating Android emulator

1. Open Android Studio -> ⠇settings -> 📲 Virtual Device Manager -> Create Device

Name	Details	Comments
Device	Pixel 4 or Higher (Without PlayStore)	Note - To root the emulator you need the one without Play Store. If you want to update the /etc/hosts file.
System Image	Android 11, API Level - 30	Note - This should be preselected if you followed along with the React Native setup guide.

1. (Optional) Follow the below instructions to start a rooted Android emulator (Required to be rooted to access the ledger running locally in order to update the device's /etc/hosts file.). Accessing ledgers available on the internet does not require rooting the device.

For more info - Refer Official Docs - Local Network limitation

1. List emulator

   emulator -list-avds
   Pixel_4_XL_API_30
   
   # Note - Your output might be different depending on the AVD you created above.
   

2. Start emulator as writable system

   emulator -avd Pixel_4_XL_API_30 -writable-system -no-snapshot-load
   

3. Open a new terminal session, and run commands described in steps 3, 4 & 5.
   Restart as root user

   adb root
   

4. Remount

   adb -s emulator-5554 remount
   

   output:

   remount succeeded
   

5. Create a file with following host entries. We will copy this file into the emulator.
   1. create a file

      vi myhosts
      

      # Enter your local machines IP address. 192.168.0.107 is an example.
      192.168.0.107 host.docker.internal
      # Ensure to add a new line
      

   2. Push the file into the emulator

      adb -s emulator-5554 push myhosts /system/etc/hosts
      

6. Verify if the host entries are updated correctly!

    # To Verify
    $ adb shell
    $ cat /etc/hosts
   
    127.0.0.1       localhost
    ::1             ip6-localhost
    192.168.0.117   host.docker.internal
   

7. Goto Emulator -> ⚙️ Settings -> 🔒 Security

   1. Set a pin for screen lock
   2. Add a Fingerprint (To enable biometric authentication)
      
8. Done!

Running app in Android emulator with Metro

Once you've created and configured your emulator:

cd app
yarn android

Alternatively, you can open ./app/android/ in Android Studio and run the app and emulator from there.

After the initial debug app has been built and deployed to the emulator, you can start the metro bundler:

cd app
yarn start

Adding QR code to emulator camera view

To place a QR code into the emulators camera view, first ensure you have set the emulators back camera to VirtualScene.

Then navigate to <Android SDK Location>/emulator/resources and open the Toren1BD.posters file in your editor.

Add a line break to the end of that file followed by:

poster custom
size 0.8 0.8
position 0 -0.1 -1.8
rotation 0.1 0 0
default custom.png

Note: You may have to reboot your emulator once this is complete for it to take effect.

Now, to add any image to the virtual scene (an image of a QR code for example), simply place the image file in this directory with the name custom.png

Troubleshooting and debugging

Hot reloading

Hot reloading may not work correctly with instantiated Agent objects. Reloading (r) or reopening the app may work. Any changes made to native modules require you to re-run the compile step.

Dependency issues, native module linking issues

If you end up changing dependencies or structures, you may need to perform the following steps:

For Android

rm -rf app/node_modules
yarn install

Clean the Android build:

cd app/android
./gradlew clean
cd ../..

Start and clean the Metro cache:

cd app
yarn start

In your second terminal, you can now run:

cd app
yarn android

Android emulator issues

If the app seems to be hung while loading in your emulator, you made need to reset the connection by running the following in the Android Studio terminal:

adb reverse tcp:8081 tcp:8081

Ensure you have your emulator's front and back camera set to use different sources, as not doing so may cause the emulator to crash whenever the camera is opened.

Debugging in Intellij and Android Emulator

UI Inspection:

1. Install react-devtools, if you haven't already

   yarn install -g react-devtools
   

2. Run devtools (you can use this only for UI inspections)

   react-devtools
   

3. In a separate terminal, run the following command. To redirect network to react-devtools

   adb reverse tcp:8097 tcp:8097
   

   Debug Application Code in Intellij or WebStorm
4. Open directory /app as project
5. Run/Debug Configuration.

[Optional] update the port to 10001. As the default port 8081 tends to run into conflicts. If you don't have other services running on port 8081. You can skip changing the port

1. Start Wallet in Debug Mode.
   

2. Now you can add breakpoint in your IDE.

   Troubleshooting:
   If debug does not showup. Ensure you have enabled debugging on the device by clicking command + m on the device and select Debug.
   >