I'm trying to compare predictions from different MLModels in SwiftUI. To do that I have to switch between them, but can't because every ML variable has its own class, so I get the error:
Cannot assign value of type 'ModelOne' to type 'ModelTwo'
Here's an example code:
import Foundation
import CoreML
import SwiftUI
let modelone = { //declaration model 1
do {
let config = MLModelConfiguration()
return try ModelOne(configuration: config)
} catch {
/*...*/
}
}()
let modeltwo = { //declaration model 2
do {
let config = MLModelConfiguration()
return try ModelTwo(configuration: config)
} catch {
/*...*/
}
}()
var imageused : UIImage! //image to classify
var modelstring = "" //string of model user chosen
var modelchosen = modelone
Button(action: { //button user decide to use model two
modelstring = "Model Two"
}) {/*...*/}
/*...*/
func classifyphoto() {
guard let image = imageused as UIImage?,
let imagebuffer = image.convertToBuffer() else {
return
}
if modelstring == "Model Two" { //if the user chosen model two, use ModelTwo
modelchosen = modeltwo // Error: Cannot assign value of type 'ModelOne' to type 'ModelTwo'
} else {
modelchosen = modelone}
let output = try? modelchosen.prediction(image: imagebuffer) //prediction with model chosen
if let output = output {
let results = output.classLabelProbs.sorted { $0.1 > $1.1 }
_ = results.map { /*...*/
}
}
}
Thank you!
The issue is that the two model classes do not have a common class or common inherited class. There are several ways to implement what you want. I think this is the best way based on your example.
class MyModel {
var model: MLModel? = nil
init(modelName: String) {
let bundle = Bundle.main
if let modelURL = bundle.url(forResource: modelName, withExtension:"mlmodelc") {
do {
self.model = try MLModel(contentsOf: modelURL)
}
catch {
print("Unable to open MLModel: \(error)")
}
}
}
}
class TestModel {
class func testModels() {
let modelOne = MyModel(modelName: "ModelOne")
let modelTwo = MyModel(modelName: "ModelTwo")
var selectedModel = modelOne
selectedModel = modelTwo
}
}
Swift is a statically typed language which means that in the general case you cannot assign a variable of one type to a variable of another type:
var int: Int = 42
int = "Hello, world!" // Not allowed: cannot assign String to Int
The problem is that modelchosen is of type ModelOne since it is initialized with modelone, thus, you cannot later assign modeltwo to it as you are trying to do.
To make that working, you have first to identify the common capabilities of ModelOne and ModelTwo. Take a look at their definition. For instance, do their .predict(image:) method return the same type? It looks like you are trying to do image classification, so a common capability could be the capability to return a String describing the image (or a list of potential objects, etc.).
When you'll have identified the common capability, you'll be able to define the common interface of your different types. This common interface can be expressed in many ways:
Using a base class
Using a protocol
Using an enum with payloads (union)
The following examples suppose that the common capabilities are:
The two networks can both be initialized with a MLModelConfiuration
They are used for image classification, i.e. they predict label (a String) describing a given image
Using a base class
The base class definition expresses those requirements like this:
class MLClassifier {
init(from config: MLModelConfig) {
fatalError("not implemented")
}
func classify(image: ImageBuffer) -> String {
fatalError("not implemented")
}
}
You then derive this base class for the two models (example with the first one:
final class ModelOne: MLClassifier {
init(from config: MLModelConfig) {
// the specific implementation for `ModelOne`...
}
func classify(image: ImageBuffer) -> String {
// the specific implementation for `ModelOne`..
}
}
Finally, you can make the variable modelchosen to be of type MLClassifier to erase the underlying concrete type of the model:
var modelchosen: MLClassifier = ModelOne(from: config1)
As MLClassifier is a common base class for both ModelOne and ModelTwo you can dynamically change the type of modelchosen whenever you need:
// Later...
modelchosen = ModelTwo(from: config2)
The variable modelchosen being of type MLClassifier ensures that you can call the .classify(image:) method whatever the concrete model type is:
func classifyphoto() {
guard let image = imageused as UIImage?,
let imagebuffer = image.convertToBuffer() else {
return
}
let output = modelchosen.classify(image: imageBuffer)
// Update the UI...
}
Using protocols
Protocols are the modern and preferred way of expressing common interfaces in Swift, they should be used over classes when possible:
protocol MLClassifier {
init(from config: MLModelConfig)
func classify(image: ImageBuffer) -> String
}
// Implement the protocol for your models
struct ModelOne: MLClassifier {
init(from config: MLModelConfig) { ... }
func classify(image: ImageBuffer) -> String { ... }
}
// Store an instance of any `MLClassfier` using an existential
var classifier: any MLClassifier = ModelOne(from: config1)
// Later...
classifier = ModelTwo(from: config2)
To sum up, the key is to identify the common capabilities of the different types you are trying to unify. For instance, if the two models output at some point a classLabelProbs of the same type, then you could use this as the common abstraction.
As a last resort, you could wrap everything in a big if-else statement, event though it is not recommended since it is not very readable, is not a good way to encapsulate common behavior and leads to a lot of code repetition:
func classifyphoto() {
guard let image = imageused as UIImage?,
let imagebuffer = image.convertToBuffer() else {
return
}
if modelstring == "Model Two" {
// Use modeltwo
let output = try? modeltwo.prediction(image: imagebuffer)
if let output = output {
let results = output.classLabelProbs.sorted { $0.1 > $1.1 }
_ = results.map { /*...*/ }
} else {
// Use modelone
let output = try? modelone.prediction(image: imagebuffer)
if let output = output {
let results = output.classLabelProbs.sorted { $0.1 > $1.1 }
_ = results.map { /*...*/ }
}
}
I am trying to interact with a smart contract I set up.
Basically the goal is to set from an iOS App 5 Parameters
projectTitle
projectLocation
projectStart
projectEnd
teamType
I want the user to set those parameters and write it on the ropsten testnetwork.
I also would like to get the contract information at a later point whenever the user feels for it.
my solidity code is working properly in remix and the contract is already deployed:
pragma solidity >=0.4.22 <0.7.0;
contract ProjectContent {
string public projectTitle;
string public projectLocation;
string public projectStart;
string public projectEnd;
string public teamType;
function projectContent(string initialProjectTitle, string initialProjectLocation, string initialProjectStart, string initialProjectEnd, string initialTeamType) public {
projectTitle = initialProjectTitle;
projectLocation = initialProjectLocation;
projectStart = initialProjectStart;
projectEnd = initialProjectEnd;
teamType = initialTeamType;
}
function setContract(string newProjectTitle, string newProjectLocation, string newProjectStart, string newProjectEnd, string newTeamType) public {
projectTitle = newProjectTitle;
projectLocation = newProjectLocation;
projectStart = newProjectStart;
projectEnd = newProjectEnd;
teamType = newTeamType;
}
function getProjectTitle() public view returns (string) {
return projectTitle;
}
function getProjectLocation() public view returns (string) {
return projectLocation;
}
function getProjectStart() public view returns (string) {
return projectStart;
}
function getProjectEnd() public view returns (string) {
return projectEnd;
}
function getTeamType() public view returns (string) {
return teamType;
}
}
My problem now is that I cannot figure out how to retrieve the data from the blockchain using the web3swift library. I am doing it like so now:
class ProjectContractViewController: UIViewController, HalfModalPresentable {
#IBOutlet weak var contractABIView: UITextView!
var halfModalTransitioningDelegate: HalfModalTransitioningDelegate?
var contractABI = "[{\"constant\":false,\"inputs\":[{\"name\":\"initialProjectTitle\",\"type\":\"string\"},{\"name\":\"initialProjectLocation\",\"type\":\"string\"},{\"name\":\"initialProjectStart\",\"type\":\"string\"},{\"name\":\"initialProjectEnd\",\"type\":\"string\"},{\"name\":\"initialTeamType\",\"type\":\"string\"}],\"name\":\"projectContent\",\"outputs\":[],\"payable\":false,\"stateMutability\":\"nonpayable\",\"type\":\"function\"},{\"constant\":false,\"inputs\":[{\"name\":\"newProjectTitle\",\"type\":\"string\"},{\"name\":\"newProjectLocation\",\"type\":\"string\"},{\"name\":\"newProjectStart\",\"type\":\"string\"},{\"name\":\"newProjectEnd\",\"type\":\"string\"},{\"name\":\"newTeamType\",\"type\":\"string\"}],\"name\":\"setContract\",\"outputs\":[],\"payable\":false,\"stateMutability\":\"nonpayable\",\"type\":\"function\"},{\"constant\":true,\"inputs\":[],\"name\":\"getProjectEnd\",\"outputs\":[{\"name\":\"\",\"type\":\"string\"}],\"payable\":false,\"stateMutability\":\"view\",\"type\":\"function\"},{\"constant\":true,\"inputs\":[],\"name\":\"getProjectLocation\",\"outputs\":[{\"name\":\"\",\"type\":\"string\"}],\"payable\":false,\"stateMutability\":\"view\",\"type\":\"function\"},{\"constant\":true,\"inputs\":[],\"name\":\"getProjectStart\",\"outputs\":[{\"name\":\"\",\"type\":\"string\"}],\"payable\":false,\"stateMutability\":\"view\",\"type\":\"function\"},{\"constant\":true,\"inputs\":[],\"name\":\"getProjectTitle\",\"outputs\":[{\"name\":\"\",\"type\":\"string\"}],\"payable\":false,\"stateMutability\":\"view\",\"type\":\"function\"},{\"constant\":true,\"inputs\":[],\"name\":\"getTeamType\",\"outputs\":[{\"name\":\"\",\"type\":\"string\"}],\"payable\":false,\"stateMutability\":\"view\",\"type\":\"function\"},{\"constant\":true,\"inputs\":[],\"name\":\"projectEnd\",\"outputs\":[{\"name\":\"\",\"type\":\"string\"}],\"payable\":false,\"stateMutability\":\"view\",\"type\":\"function\"},{\"constant\":true,\"inputs\":[],\"name\":\"projectLocation\",\"outputs\":[{\"name\":\"\",\"type\":\"string\"}],\"payable\":false,\"stateMutability\":\"view\",\"type\":\"function\"},{\"constant\":true,\"inputs\":[],\"name\":\"projectStart\",\"outputs\":[{\"name\":\"\",\"type\":\"string\"}],\"payable\":false,\"stateMutability\":\"view\",\"type\":\"function\"},{\"constant\":true,\"inputs\":[],\"name\":\"projectTitle\",\"outputs\":[{\"name\":\"\",\"type\":\"string\"}],\"payable\":false,\"stateMutability\":\"view\",\"type\":\"function\"},{\"constant\":true,\"inputs\":[],\"name\":\"teamType\",\"outputs\":[{\"name\":\"\",\"type\":\"string\"}],\"payable\":false,\"stateMutability\":\"view\",\"type\":\"function\"}]"
let str = "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var contractAddress = EthereumAddress("0x11A0c067d7481240dCA57457eff77fc98dEAdE0F")
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
func callContract(Password: String) {
// Get from address from private key
let formattedKey = Password.trimmingCharacters(in: .whitespacesAndNewlines)
let dataKey = Data.fromHex(formattedKey )!
// ### use [passKey]
let keystore = try! EthereumKeystoreV3(privateKey: dataKey, password: "")!
let keyData = try! JSONEncoder().encode(keystore.keystoreParams)
// let address = keystore.addresses!.first!.address
let address = keystore.addresses!.first!.address
let ethAddress = EthereumAddress(address)
let infura = Web3.InfuraMainnetWeb3()
// 1
let contract = infura.contract(contractABI, at: contractAddress, abiVersion: 2)
// 2
var options = TransactionOptions.defaultOptions
options.from = keystore.addresses!.first!
// 3
let data = Data.init(hex: str)
let transactionIntermediate = contract?.method("getProjectTitle", parameters: [address] as [AnyObject], extraData: data, transactionOptions: options)
// 4
let result = transactionIntermediate!.call(transactionOptions: options)
switch result {
// 5
case .success(let res):
let ans = res["0"] as! Bool
DispatchQueue.main.async {
completion(Result.Success(ans))
}
case .failure(let error):
DispatchQueue.main.async {
completion(Result.Error(error))
}
}
}
}
I get an error for the resultsaying:
"Call can throw, but it is not marked with 'try' and the error is not handled"
and in general I find it really hard to set up the interaction with a smart contract abi.
I am already using the web3swift functionality for sending transactions at it works like a charm.
Maybe someone knows how I can record information on the blockchain and get it using web3swift.
You are close. Starting with the error "Call can throw, but it is not marked with 'try' and the error is not handled" this is caused by trying to call a contract function without using the Try Catch pattern. Do to the way web3 library is designed this pattern is necessary for all write and call methods.
// Incorrect
let result = transactionIntermediate!.call(transactionOptions: options)
// Correct
do {
let result = try transactionIntermediate!.call(transactionOptions: options)
}catch{
print("Error trying to call method \(error)")
}
Additionally, I recommend using the DispatchQueue.main.async along with Promise Kit library when making your contract calls.
ABIs are hard to read and messy, don't recommend using it to help find callable methods and parameters within the contract. Instead I would have the contract open along side Xcode and through the use of either an enum or struct containing all the contract methods that are going to be used.
// Methods available within the contract
enum ContractMethods:String {
case projectContract = "projectContent"
case setContract = "setContract"
case getProjectTitle = "getProjectTitle"
case getProjectLocation = "getProjectLocation"
case getProjectStart = "getProjectStart"
case getProjectEnd = "getProjectEnd"
case getTeamType = "getTeamType"
}
// Usage
ContractMethods.setContract.rawValue
I moved the ABI to a separate file within xcode to keep it clean. Here is link to the file.
Here is a good example to help get you started. Check out my GitHub repo for the improved version.
import UIKit
import web3swift
import PromiseKit
struct Wallet {
let address: String
let data: Data
let name:String
let isHD:Bool
}
struct HDKey {
let name:String?
let address:String
}
var password = "" // leave empty for ganache or use your wallet password
let privateKey = "<PrivateKey>" // Private key of wallet
let walletName = "MyWallet"
let contractAddress = "<ContractAddress>" // 0x11A0c067d7481240dCA57457eff77fc98dEAdE0F
let endpoint = URL(string:"http://127.0.0.1:7545")! // Im using Ganache but it might look like endpoint = URL(string:"https://rinkeby.infura.io/v3/<APIKEY>")!
let abiVersion = 2
class ViewController: UIViewController {
// Mock data used within contract
let projectTitle = "HouseSiding"
let projectLocation = "299 Race Ave. Dacula, GA 30019"
let projectStart = "May 14, 2021"
let projectEnd = "June 15, 2021"
let teamType = "Collaboration"
var web3:web3?
var contract:web3.web3contract?
override func viewDidLoad() {
super.viewDidLoad()
// 1. Create wallet using a private key
let formattedKey = privateKey.trimmingCharacters(in: .whitespacesAndNewlines)
let dataKey = Data.fromHex(formattedKey)!
let keyStore = try! EthereumKeystoreV3(privateKey:dataKey, password: password)!
let keyData = try! JSONEncoder().encode(keyStore.keystoreParams)
let address = keyStore.addresses!.first!.address
let wallet = Wallet(address: address, data: keyData, name: walletName, isHD: false)
// 2. Construct web3 and keystoreManager
do {
web3 = try Web3.new(endpoint)
let data = wallet.data
var keystoreManager: KeystoreManager
if wallet.isHD {
let keystore = BIP32Keystore(data)!
keystoreManager = KeystoreManager([keystore])
}else{
let keystore = EthereumKeystoreV3(data)!
keystoreManager = KeystoreManager([keystore])
}
print(keystoreManager.addresses)
web3!.addKeystoreManager(keystoreManager)
let ethContractAddress = EthereumAddress(contractAddress, ignoreChecksum: true)!
contract = web3!.contract(contractABI, at: ethContractAddress, abiVersion: abiVersion)!
}catch{
print ("Failed to construct contract and/or keystoreManager \(error)")
}
// 3. Create and callout a contract method
//let parameters = [projectTitle,projectLocation,projectStart,projectEnd,teamType] as [AnyObject] // parameters used to created a new project
let parameters = [] as [AnyObject] // no parameters
let response = Promise<Any> { seal in
DispatchQueue.global().async {
// Catch errors within async call
do {
// No extra data for method call
let extraData: Data = Data()
// Options for method call
var options = TransactionOptions.defaultOptions
options.from = EthereumAddress(wallet.address)! // current wallet address
// Leave automatic for gas
options.gasPrice = .automatic
options.gasLimit = .automatic
// Calling get Project title from contract
// NOTE: First call setContract with parameters
let tx = self.contract!.method("getProjectTitle",
parameters: parameters,
extraData: extraData,
transactionOptions: options)
// Depending on the type of call a password might be needed
//if password != nil {
//let result = try tx!.send(password: password)
// seal.resolve(.fulfilled(true))
//}else{
let result = try tx!.call()
// fulfill are result from contract
let anyResult = result["0"] as Any
seal.resolve(.fulfilled(anyResult))
//}
}catch {
// error
seal.reject(error)
}
}
}
response.done({result in
print(result) // Optional(HouseSiding)
})
}
}
I am new to Firebase and Swift. My previous question was very vague due to a misunderstanding on my part. In a class named "A" for example I am trying to create an object of class "B" that contains the fetchARImageTargets function that I have below. I am trying to assign the array ARImageTargets to a var in class "A" however, the listAll completion is not returned in time, which results in the var being empty. Is there a way that I can edit my function or class to avoid the var being set prematurely?
let ARImageTargetStorageRef = Storage.storage().reference().child("ImageTargets")
self.fetchARImageTargets(ref: ARImageTargetStorageRef)
func fetchARImageTargets(ref: StorageReference) {
ref.listAll { (result, error) in
if let error = error {
print(error)
}
for prefix in result.prefixes {
self.fetchARImageTargets(ref: prefix)
}
for item in result.items {
item.getMetadata { (metadata, error) in
if let error = error {
print(error)
} else {
var imageTarget = ARImageTarget()
item.downloadURL(completion: { (url, error) in
imageTarget.ImageURL = url
})
imageTarget.Id = metadata?.customMetadata?["Id"] as String?
let width = metadata?.customMetadata?["PhysicalWidth"] as String?
imageTarget.PhysicalWidth = CGFloat(truncating: NumberFormatter().number(from: width!)!)
self.ARImageTargets.append(imageTarget)
}
}
}
}
}
I need certain types of system information available to configure my app. I want to achieve this by having a model class which makes the information available. I know how to get the desired information but i am struggling to store this gathered information in the properties of my model class.
i want to be able to:
let sysInfoModel = SysInfoModel()
let installedOsVersion = sysInfoModel.osVersion
The model class should be instantiated from the vieController which needs this information to set up.
I think my whole attempt is wrong to achieve such thing. What is the proper way to do so?
class SysInfoModel {
// Properties
let macModel: String?
let osVersion: String?
// Initialization
init() {
if let actualModel = getMacModel() { //ERROR: 'self' used in method call 'getMacModel' before all stored properties are initialized
self.macModel = actualModel
} else {
macModel = "Hardware model not found"
}
if let actualOsVersion = getOsVersion() { // ERROR: 'self' used in method call 'getOsVersion' before all stored properties are initialized
osVersion = actualOsVersion
} else {
osVersion = "OS Version not available"
}
}
// Returns the hardware model identifier as a string
func getMacModel() -> String? {
var modelIdentifier: String?
let service = IOServiceGetMatchingService(kIOMasterPortDefault, IOServiceMatching("IOPlatformExpertDevice"))
if let modelData = IORegistryEntryCreateCFProperty(service, "model" as CFString, kCFAllocatorDefault, 0).takeRetainedValue() as? Data {
modelIdentifier = String(data: modelData, encoding: .utf8)
}
IOObjectRelease(service)
return modelIdentifier
}
// Returns the OS Version as a String
func getOsVersion() -> String? {
let osVersion: OperatingSystemVersion = ProcessInfo.processInfo.operatingSystemVersion
let osVersionString = String("\(osVersion.majorVersion).\(osVersion.minorVersion).\(osVersion.patchVersion)")
return osVersionString
}
}
Update after matt's answer:
// Properties
var askSystem: AskTheSystem
let macModel: String?
let osVersion: String?
init() {
askSystem = AskTheSystem()
if let actualModel = askSystem.getMacModel() {
self.macModel = actualModel
} else {
macModel = "Hardware model not found"
}
if let actualOsVersion = askSystem.getOsVersion() {
osVersion = actualOsVersion
} else {
osVersion = "OS Version not available"
}
}
I did, there is the possibility to put the functions getMacModel() & getOsVersion() in a separate class called AskTheSystem. Instantiate it in the SysInfoModel.
It works but is this good practice ? i don't see the point in adding another class just for those functions ? What is the proper way to do so ?
I agree with matt, proper is a judgement.
A reasonable solution are lazy instantiated properties, both values are retrieved once when the property is accessed the first time
class SysInfoModel {
// Returns the hardware model identifier as a string
lazy var macModel : String = {
let service = IOServiceGetMatchingService(kIOMasterPortDefault, IOServiceMatching("IOPlatformExpertDevice"))
defer{IOObjectRelease(service)}
guard let modelData = IORegistryEntryCreateCFProperty(service, "model" as CFString, kCFAllocatorDefault, 0).takeRetainedValue() as? Data else {
return "Hardware model not found"
}
return String(data: modelData, encoding: .utf8)!
}()
// Returns the OS Version as a String
lazy var osVersion : String = {
let osVersion = ProcessInfo.processInfo.operatingSystemVersion
return "\(osVersion.majorVersion).\(osVersion.minorVersion).\(osVersion.patchVersion)"
}()
}
I'm working with VPN and I ask this question but now I would like to create a VPN profile using L2TP Protocol, not the IPSec protocol.
I have all the information I need (user, server, password, pre sharedKey) and the service is correctly ON. I'm trying so to create an App that simply connect to the VPN by creating the right Setting Profile like the app '1.1.1.1' in the App Store.
I'm using the NEVPNProtocolIPSec Class but I think is wrong. The is no class for L2PT protocol?
In the device setting I'm able to manually configure the VPN for L2PT but how ca I do it using NEVPNManager??
Here my code:
class VPN {
let vpnManager = NEVPNManager.shared();
private var vpnLoadHandler: (Error?) -> Void { return
{ (error:Error?) in
if ((error) != nil) {
print("Could not load VPN Configurations")
return;
}
let p = NEVPNProtocolIPSec()
p.username = "myUsername"
p.serverAddress = "myAddressServer"
p.authenticationMethod = NEVPNIKEAuthenticationMethod.sharedSecret
let kcs = KeychainService();
kcs.save(key: "SHARED", value: "sharedPsw")
kcs.save(key: "VPN_PASSWORD", value: "password")
p.sharedSecretReference = kcs.load(key: "SHARED")
p.passwordReference = kcs.load(key: "VPN_PASSWORD")
p.useExtendedAuthentication = true
p.disconnectOnSleep = false
self.vpnManager.protocolConfiguration = p
self.vpnManager.localizedDescription = "myDescription"
self.vpnManager.isEnabled = true
self.vpnManager.isOnDemandEnabled = true
self.vpnManager.saveToPreferences(completionHandler: self.vpnSaveHandler)
}
}
private var vpnSaveHandler: (Error?) -> Void { return
{ (error:Error?) in
if (error != nil) {
print("Could not save VPN Configurations")
return
} else {
do {
try self.vpnManager.connection.startVPNTunnel()
} catch let error {
print("Error starting VPN Connection \(error.localizedDescription)");
}
}
}
}
public func connectVPN() {
//For no known reason the process of saving/loading the VPN configurations fails.On the 2nd time it works
do {
try self.vpnManager.loadFromPreferences(completionHandler: self.vpnLoadHandler)
} catch let error {
print("Could not start VPN Connection: \(error.localizedDescription)" )
}
}
public func disconnectVPN() ->Void {
vpnManager.connection.stopVPNTunnel()
}
I't working but it create a VPN Configuration for IPSec but I want the L2PT. Can somebody else help me please?
Maybe somebody face the same problem.