ioskevinshah

/// Variable Declaration(s)
class var isFaceIdAvailable: Bool {
    let context: LAContext = LAContext()
    let evaluate = context.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: nil)
    if #available(iOS 11.0, *) {
        return (context.biometryType == .faceID)
    }
    return evaluate
}

ioskevinshah

/// Change default message as per your need.
fileprivate static var defaultReasonMessage: String {
    return LocalAuthentication.isFaceIdAvailable ? kFaceIdAuthenticationReason : kTouchIdAuthenticationReason
}

ioskevinshah

let kReasonMessage = "Biometeric required your authentication."

/// Biometric Default Reason(s)
let kBiometryNotAvailableReason = "Biometric authentication is not available for this device."

/// Common Message(s)
let kSetPasscode = "Please set device passcode for authentication."

/// TouchID Related Message(s)
let kTouchIdAuthenticationReason = "Confirm your fingerprint to authenticate."

ioskevinshah

import LocalAuthentication

/// AuthenticationBlockState
enum AuthenticationBlockState {
    case success
    case failed
    case canceledByUser
    case fallback
    case canceledBySystem
    case passcodeNotSet

ioskevinshah

/// Block Declaration(s)
typealias authenticationBlock = ((AuthenticationBlockState) -> ())

ioskevinshah

class func authenticateUserWithBioMetrics(_ reasonMessage: String, cancelTitle: String? = "", block: @escaping authenticationBlock) {
    let context: LAContext = LAContext()
    context.localizedCancelTitle = cancelTitle
    context.localizedFallbackTitle = "Passcode"
    evaluate(.deviceOwnerAuthentication, reason: (reasonMessage.isEmpty ? defaultReasonMessage : reasonMessage), context: context, block: block)
}

ioskevinshah

fileprivate static func evaluate(_ policy: LAPolicy, reason: String, context: LAContext, block: @escaping authenticationBlock) {
        context.evaluatePolicy(policy, localizedReason: reason) { (isSuccess, error) in
            block(AuthenticationBlockState.initWith(error as? LAError))
        }
    }

ioskevinshah

@IBAction func tapBtnAuthenticate(_ sender: UIButton) {
    LocalAuthentication.authenticateUserWithBioMetrics(kReasonMessage) { [weak self] (authenticationState) in
        guard let self = self else {
            return
        }
        switch authenticationState {
        case .success:
            self.showAlert("Successfully Authenticated")
        case .canceledByUser, .fallback, .canceledBySystem:
            break

ioskevinshah

/// LocalAuthentication
class LocalAuthentication: NSObject {
    
    /// Variable Declaration(s)
    class var isFaceIdAvailable: Bool {
        let context: LAContext = LAContext()
        let evaluate = context.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: nil)
        if #available(iOS 11.0, *) {
            return (context.biometryType == .faceID)
        }

ioskevinshah

/// Variable Declaration(s)
var lblTitle: UILabel = {
    var lbl: UILabel = UILabel()
    lbl.translatesAutoresizingMaskIntoConstraints = false
    lbl.backgroundColor = .clear
    lbl.textAlignment = .center
    lbl.adjustsFontSizeToFitWidth = true
    lbl.minimumScaleFactor = 0.75
    lbl.textColor = .darkText
    lbl.font = .boldSystemFont(ofSize: UIFont.systemFontSize)