swift - 用于表单验证的信号和观察者(Reactive Swift)未按预期工作

Question

我正在使用响应式 swift 进行表单验证。但我在重置值和信号值时遇到了问题。

当我按照验证规则的指示正确填写所有文本字段时，所有信号(文本字段连续文本值)都会产生真值，这将允许我发送表单数据。我在完成表单提交后重置了文本字段的值。之后我向所有信号观察者发送假值。但是，当我开始填充文本字段时，它将获得先前的真实信号，并允许我在不应用任何验证规则的情况下发送数据。这意味着我无法重置信号值

任何帮助将不胜感激。

我的问题:

import UIKit
import ReactiveSwift
import Result

class ContactVC: BaseViewController {

    @IBOutlet weak var textFieldName: JVFloatLabeledTextField!
    @IBOutlet weak var textFieldPhoneOL: JVFloatLabeledTextField!
    @IBOutlet weak var textViewComent: UITextView!
    @IBOutlet weak var textFieldLocationOL: JVFloatLabeledTextField!
    @IBOutlet weak var textFieldEmailOL: JVFloatLabeledTextField!
    @IBOutlet weak var btnSubmitOL: PGSpringAnimation!

    var (nameValidationSignal, nameValidationObserver) = Signal<Bool, NoError>.pipe()
    var (phoneValidationSignal, phoneValidationObserver) = Signal<Bool, NoError>.pipe()
    var (emailValidationSignal, emailValidationObserver) = Signal<Bool, NoError>.pipe()
    var (locationValidationSignal, locationValidationObserver) = Signal<Bool, NoError>.pipe()
    var (commentValidationSignal, commentValidationObserver) = Signal<Bool, NoError>.pipe()


    override func viewDidLoad() {
        super.viewDidLoad()

    }


    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        self.formValidation()
    }

    // MARK: - submit button action
    @IBAction func btnSubmitAction(_ sender: Any) {

        let params  = ["name":textFieldName.text!,"email":textFieldEmailOL.text!,"location":textFieldLocationOL.text!,"message":textViewComent.text!,"phone":textFieldPhoneOL.text!]

        APIManager(urlString:enumUrl.ContactAdmin.mainURL(),parameters:params as [String : AnyObject]?,method: .post).handleResponse(viewController: self, progressMessage: "downloading", completionHandler:  { (response : AllResponse) in

            self.nameValidationObserver.send(value: false)
            self.emailValidationObserver.send(value: false)
            self.phoneValidationObserver.send(value: false)
            self.locationValidationObserver.send(value: false)
            self.commentValidationObserver.send(value: false)

            self.btnSubmitOL.backgroundColor = UIColor.gray
            self.btnSubmitOL.isUserInteractionEnabled = false

        })

    }
    // MARK: - validation textfield

    func formValidation(){

        self.btnSubmitOL.backgroundColor = UIColor.gray
        self.btnSubmitOL.isUserInteractionEnabled = false

        // Create signals

        // Signals for TextFields
        self.nameValidationSignal = self.textFieldName.reactive.continuousTextValues
            .map{ ($0?.characters.count ?? 0) >= 3 }
        self.phoneValidationSignal = self.textFieldPhoneOL.reactive.continuousTextValues
            .map{ ($0?.characters.count ?? 0 ) >= 8 }
        self.emailValidationSignal = self.textFieldEmailOL.reactive.continuousTextValues
            .map{ $0?.isEmail ??  false }
        self.locationValidationSignal = self.textFieldLocationOL.reactive.continuousTextValues
            .map{ ($0?.characters.count ?? 0) >= 3 }
        self.commentValidationSignal = self.textViewComent.reactive.continuousTextValues
            .map{ ($0?.characters.count ?? 0) >= 5 }

        // Observe TextFields Singals for Changing UI
        self.nameValidationSignal.observeValues { value in
            self.textFieldName.floatingLabelActiveTextColor = value ? UIColor.red : UIColor.black
            self.textFieldName.floatingLabel.text = value ? "name".localize : "Name must be greater than 4 characters".localize
        }

        self.phoneValidationSignal.observeValues { value in
            self.textFieldPhoneOL.floatingLabelActiveTextColor = value ? UIColor.red : UIColor.black
            self.textFieldPhoneOL.floatingLabel.text = value ? "phone".localize : "Phone must be greater than 7 characters".localize
        }

        self.emailValidationSignal.observeValues { value in
            self.textFieldEmailOL.floatingLabelActiveTextColor = value ? UIColor.red : UIColor.black
            self.textFieldEmailOL.floatingLabel.text = value ? "email".localize : "Email must be of type example@test.com".localize
        }

        self.locationValidationSignal.observeValues { value in
            self.textFieldLocationOL.floatingLabelActiveTextColor = value ? UIColor.red : UIColor.black
            self.textFieldLocationOL.floatingLabel.text = value ? "location".localize : "Loation must be greater than 4 characters".localize
        }

        self.commentValidationSignal.observeValues { value in
            self.textViewComent.textColor = value ? UIColor.red : UIColor.black
        }


        let formValidationSignal = nameValidationSignal.combineLatest(with: phoneValidationSignal).combineLatest(with: emailValidationSignal).combineLatest(with: locationValidationSignal).combineLatest(with: commentValidationSignal)
            .map {
                $0.0.0.0 && $0.0.0.1 &&  $0.0.1 && $0.1 && $1
        }


        formValidationSignal.observeValues {
                self.btnSubmitOL.isUserInteractionEnabled = $0
                self.btnSubmitOL.backgroundColor = $0 ? UIColor.appRedColor() : UIColor.gray
        }
    }

}

我已经解决了这个问题，但我认为这不是完美的方法，响应式(Reactive)也不是我解决的方法。 我正在等待完美或最被接受的解决方案。 非常感谢任何帮助或回答。

Answer 1

这是我对这个问题的一种更惯用的方法(为了示例简化为只有两个输入)。

首先，有一个 ViewModel，它具有 MutableProperty 来保存输入值。如果您想要输入的其他初始值，您可以将这些值初始化为 nil 以外的任何值。

ViewModel als 具有用于验证输入的属性。 Property.map 用于从输入推断有效值。顺便说一句，您可以使用 Signal.combineLatest(signal1, signal2, signal3, ...) 而不是 signal1.combineLatest(with: signal2).combineLatest(with: signal3)...

最后，有一个执行提交的Action。在 ViewController 中，我们可以将此 Action 绑定(bind)到按钮。 Action 每次执行时都会发送一个空字符串。操作的 .values 信号用于在执行操作后重置输入。 如果提交可能会产生错误，您应该相应地进行处理。

class ViewModel {
    let username = MutableProperty<String?>(nil)
    let address = MutableProperty<String?>(nil)
    let usernameValid: Property<Bool>
    let addressValid: Property<Bool>
    let valid: Property<Bool>
    let submit: Action<(String?, String?), String, NoError>

    init() {

        self.usernameValid = username.map {
            return ($0 ?? "").characters.count > 0
        }
        self.addressValid = address.map {
            return ($0 ?? "").characters.count > 0
        }

        self.valid = Property.combineLatest(self.usernameValid, self.addressValid).map { (usernameValid, addressValid) in
            return usernameValid && addressValid
        }
        self.submit = Action(enabledIf: self.valid) { input in
            print("Submit with username \(input.0) and address \(input.1)")
            return SignalProducer<String, NoError>(value: "")
        }

        self.username <~ self.submit.values
        self.address <~ self.submit.values
    }
}

然后是 ViewController 中的设置:

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
    self.username.reactive.text <~ self.viewModel.username
    self.address.reactive.text <~ self.viewModel.address

    self.viewModel.username <~ self.username.reactive.continuousTextValues
    self.viewModel.address <~ self.address.reactive.continuousTextValues

    self.submit.reactive.pressed = CocoaAction(self.viewModel.submit) { [weak self] (button) -> (String?, String?) in
        return (self?.username.text, self?.address.text)
    }
}

首先，ViewModel 的 MutableProperty 绑定(bind)到 UITextField。这样，文本字段不仅会初始化为 ViewModel 中属性的初始值，还会在 ViewModel 中的属性更新时更新它们 - 这样您就可以在执行提交操作时重置它们。

然后，UITextFields 的continuousTextValues 绑定(bind)到 ViewModel 的属性。由于 continuousTextValues 如果以编程方式设置文本，则不会触发，仅当它由用户设置时，这不会创建循环。

最后，CocoaAction 用于将submit Action 绑定(bind)到按钮的pressed Action 。 inputTransformer 函数用于在每次按下按钮时发送输入的当前值。

您还可以订阅 viewModel 的各个 usernameValid/addressValid 属性，以在此处为用户设置显示验证错误。