ETHSignerDemo

Ethereum signer APP , MVVM + RxSwift implementation in iOS

A simple app to sign text messages with Ethereum private key and to verify them. The app allows a user to enter Ethereum private key, and to display the account balance on the Rinkeby network. It also allows a user to sign any message with the user’s private key and to check if a provided signature with the initial message is something that a user signed before.

Xcode 11

MVVM architecture + Router

MVVM (Model-View-ViewModel) is derived from MVC(Model-View-Controller). It is introduced to solve existing problems of Cocoa's MVC architecture in iOS world. One of its feature is to make a better seperation of concerns so that it is easier to maintain and extend.

Model: It is simillar to model layer in MVC (contains data )
View: UIViews + UIViewControllers
ViewModel: A mediator to glue two above layer together (contains business logic).
Router: When the user taps to navigate to the next scene . A router extracts this navigation logic out of the view controller. It is also the best place to pass any data to the next scene. As a result, the view controller is left with just the task of controlling views.
Builder: initialize ViewController, ViewModel and Router provide the ViewController to the outside world (via the viewController() method) if the Scene needs some initial data it is injected into the Builder who then injects it into the ViewModel

An important point in MVVM is that it uses a binder as communication tool between View and ViewModel layers. A technique named Data Binding is used with RxSwift .

Repository

Implement repository Pattren to give the viewModel one entry point for loading data from server or from mockups for unit testing .

Example

protocol BalanceRepository {
    func getBalance(wallet: EthereumWallet, completionHandler: @escaping((Result<String,Error>) -> Void))
}

class RemoteBalanceRepository: BalanceRepository {}

class MockupBalanceRepository: BalanceRepository {}

Modules

Modules divied the app into Modules each Module represent a feature of the app . I just divid the APP to two Modules

ETHSignerDemo The main Module and have all the app screeens
ETHCore A static framework Target Manage the communcation with etherem APIs

Sences (Screens)

Sences divied each Module in the app into Sences each Sence has screens inside it
each Sence have it is own storyboard inside Sence each screen have folder contain MVVM classes

We have only two Sences on the ETHSignerDemo module
Main Splash screen , Setup Screen and Account Screen
SigningAndVerification Signing Screen , Signature Screen and Verification Screeen

Storyboard

each Sence has his own storyboard to make life easer when want to access any view contoller inside Sences you can add storyBord name here Extension -> Storyboard Extension -> extension UIStoryboard -> enum Storyboard: String

be sure to use your viewcontroller class as the viewcontroller id on inside StoaryBoard


enum Storyboard: String {
case main
case signing

var filename: String {
return rawValue.capitalized
}
}

then when ever you want to use it call it like this

let viewController : AccountViewController = UIStoryboard.storyboard(.main).instantiateViewController()

Libraries

ETHSignerDemo Target

[RxSwift '5.0.0' + RxCocoa '5.0.0'] to do "data binding" job which binds ViewModel and View
[ReachabilitySwift '4.3.1'] to listen to network status change
['SwiftLint' '0.33.0'] to enforce Swift style and conventions
['QRCodeReader.swift' '10.1.0'] Qr Code reader

ETHCore Target

['web3swift' '2.1.6'] Elegant Web3js functionality in Swift. Native ABI parsing and smart contract interactions on Ethereum network

AliAdam/ETHSignerDemo