PolkaJ Android Support

• Team Name: Nathan Schwermann
• Payment Address: 0x454cfAa623A629CC0b4017aEb85d54C42e91479d
• Status: Terminated

Project Overview 📄

This proposal is a follow-up to the PolkaJ grant https://github.com/w3f/Open-Grants-Program/pull/12 I am not affiliated with the original team, but I have spoken with them about this propoal and they have encouraged me to submit it.

Overview

The PolkaJ java client is built using Java 11 APIs and native x86 code which can not run on Android. This project proposal will make the necessary changes to support the Android platform as well as provide examples.

Project Details

We will make the following changes and additions to the PolkaJ project in order to support Android versions 7 and up.

• Build script changes to also compile the rust code to ARM in addition to x86 based on the target
• Make necessary changes to JNI code to support ARM when needed and remove Java 9 dependency
• Add RpcCallAdapter and SubscriptionCallAdapter to client Builder interface
• Refactor polkaj-api-http and polkaj-api-ws which both use Java 11 and can not be used on Android to implement the new Call and Subscription Factory apis
• Extract and refactor tests from polkaj-api-http and polkaj-api-ws to be reusable for any implementations of the factory as well as additional coverage for Builder changes to support factories
• Add new module polkaj-okhttp which will implement RpcCallAdapter and SubscriptionCallAdapter using okhttp, the most widely adopted http client used in the Android development community.
• Unit test against shared tests for java.net versions of factories, with the same or higher code coverage.
• polkaj-ktx modules adding support kotlin extensions and coroutine support
• Example Android app, uses existing command line examples in Android GUI
• Update documentation for build script changes and for examples on each platform
• Fix broken balance example on OSX
• Add new artifacts polkaj-schnorrkel_android.jar, polkaj-okhttp.jar

Ecosystem Fit

This is an improvement and addition to an existing project.

Team 👥

Team members

• Nathan Schwermann

Contact

• Contact Name: Nathan Schwermann
• Contact Email: schwiz@gmail.com

Legal Structure

Individual / Sole Proprietor

Team's experience

I have ten years of experience in Android client development in the telecom and payment industries. I have led and maintained development on applications with millions of monthly active users.

Team Code Repos

• https://github.com/nschwermann

Team LinkedIn Profiles

• https://www.linkedin.com/in/nathanschwermann/

Development Status 📖

• I have completed parts 1, 1b, 2a, 5, 90% complete 3a and 50% 4a from milestone 1.

Development Roadmap 🔩

Overview

• Total Estimated Duration: 3 Months
• Full-time equivalent (FTE): 1
• Total Costs: 21,000 DAI

Milestone 1 Client refactoring

• Estimated Duration: 1 month (2 weeks left after re-approval of milestone delivery)
• FTE: 1
• Costs: 7,000 DAI

Number	Deliverable	Specification
0a.	License	Apache 2.0
0b.	Documentation	We will provide both inline documentation of the code and update the existing examples documentation with api changes
0c.	Testing Guide	We will maintain or improve current code coverage.
1.	schnorrkel module remove Java 9 dependency
1b.	schnorrkel module Mac OS Compatibility	Fix native library loading on mac
2a.	api-base: Factories	We will add common Builder interface with added components for RpcCallFactory and SubscriptionFactory
2b.	api-base: Factory Tests	We will extract existing http/ws tests to new common factory tests suite
3a.	api-http: Factory	Refactor to implement RpcCallFactory
3b.	api-http: Tests	Unit tests 90% coverage Integration tests with api base previously extracted from this module
4a.	api-ws: Factory	Refactor to implement SubscriptionCallAdapter
4b.	api-ws: Tests	Unit tests 90% coverage Integration tests with api base previously extracted from this module
5	examples	Fix Balance example not working on OSX

Milestone 2 OkHttp / Java 8 Compatible

• Estimated Duration: 1 month
• FTE: 1
• Costs: 7,000 DAI

Number	Deliverable	Specification
0a.	License	Apache 2.0
0b.	Documentation	We will provide both inline documentation of the code and documentation for using okhttp module.
0c.	Testing Guide	Will have 90% code coverage Unit tests and Integration test with api base
1.	polkaj-api-okhttp module	Will add new module with RpcCallFactory and SubscriptionFactory implementations. Adds new artifact polkaj-okhttp.jar
2.	Example	Will update examples and example documentation to allow switching between okhttp and http/ws socket implementations
3.	schnorrkel module Android Compatibility	Will build RUST code for ARM adds new artifact polkaj-schnorrkel_android.jar

Milestone 3 Android and Kotlin

• Estimated Duration: 1 month
• FTE: 1
• Costs: 7,000 DAI

Number	Deliverable	Specification
0a.	License	Apache 2.0
0b.	Documentation	We will provide both inline documentation of the code and documentation for using kotlin module and including polkaj inside an Android project.
0c.	Testing Guide	Will have 90% code coverage Unit tests and Integration test with api base
1.	polkaj-ktx module	Will include support for Kotlin coroutines and additional kotlin convenience methods
2a.	Example	Will port desktop examples into an Android app with a simple GUI to select each example and allow user input where possible
2b.	Example blog	Will write blog post and submit to medium explaining new changes to PolkaJ made to support Android and a walk through guide how to integrate PolkaJ into your Android project.

Future Plans

I will continue to look for use cases where Android can be used in the polka dot network. I am excited to see the future and hope to remain involved.