我有一个返回Bool Observable的函数,具体取决于它是否正常.
func test() -> Observable<Bool> {
if everythingIsOk {
return just(true)
}
return just(false) <- how can i here return a custom error to retrieve what failed?
}
我正在尝试将项目转换为使用RxSwift和MVVM.我有一个服务,在每个应用程序启动时同步来自Parse的数据列表,我基本上想确保我采取正确的方法.
我所做的是成为一个可变主题,然后允许我的模型听这个.ParseService:
let rx_parseMushrooms = Variable<[ParseMushroom]>([])
MushroomLibraryModel:
_ = parseService.rx_parseMushrooms
.asObservable()
.map { (parseMushrooms:[ParseMushroom]) -> [Mushroom] in
let mushrooms = parseMushrooms.map { (parseMushroom:ParseMushroom) -> Mushroom in
let mushroom = Mapper<Mushroom>().map(parseMushroom.dictionaryWithValuesForKeys(parseMushroom.allKeys()))
return mushroom!
}
return mushrooms
}
.subscribeNext({ (mushrooms:[Mushroom]) -> Void in
self.mushrooms = mushrooms
print(mushrooms)
})
我也是这样表达同步状态的.
ParseService:
struct SyncState {
enum State {
case Unsynced, ConnectingToServer, SyncingInfo, FetchingImageList, SyncingImages, SyncComplete, SyncCompleteWithError
}
var infoToSync = 0
var imagesToSync = 0
var imagesSynced = 0
var state = State.Unsynced
} …我在RxSwift的示例代码中读取了双向绑定运算符.
func <-> <T>(property: ControlProperty<T>, variable: Variable<T>) -> Disposable {
let bindToUIDisposable = variable.asObservable()
.bindTo(property)
let bindToVariable = property
.subscribe(onNext: { n in
variable.value = n
}, onCompleted: {
bindToUIDisposable.dispose()
})
return StableCompositeDisposable.create(bindToUIDisposable, bindToVariable)
}
当property改变,它会通知变量,并设置变量的值,而该变量的值时,它会通知物业.我认为这会导致无休止的循环......
我有2个UITextField属性和1个UIButton的授权控制器.我想将View绑定到ViewModel,但不知道如何操作.这是我的AuthorizatioVC.swift:
class AuthorizationViewController: UIViewController {
let disposeBag = DisposeBag()
@IBOutlet weak var passwordTxtField: UITextField!
@IBOutlet weak var loginTxtField: UITextField!
@IBOutlet weak var button: UIButton!
override func viewDidLoad() {
super.viewDidLoad()
addBindsToViewModel()
}
func addBindsToViewModel(){
let authModel = AuthorizationViewModel(authClient: AuthClient())
authModel.login.asObservable().bindTo(passwordTxtField.rx_text).addDisposableTo(self.disposeBag)
authModel.password.asObservable().bindTo(loginTxtField.rx_text).addDisposableTo(self.disposeBag)
//HOW TO BIND button.rx_tap here?
}
}
这是我的AuthorizationViewModel.swift:
final class AuthorizationViewModel{
private let disposeBag = DisposeBag()
//input
//HOW TO DEFINE THE PROPERTY WHICH WILL BE BINDED TO RX_TAP FROM THE BUTTON IN VIEW???
let authEvent = ???
let login = …我想取消订阅RxSwift中的Observable.为了做到这一点,我曾经将Disposable设置为nil.但在我看来,在更新到RxSwift 3.0.0-beta.2后,这个技巧不起作用,我无法取消订阅Observable:
//This is what I used to do when I wanted to unsubscribe
var cancellableDisposeBag: DisposeBag?
func setDisposable(){
cancellableDisposeBag = DisposeBag()
}
func cancelDisposable(){
cancellableDisposeBag = nil
}
那么可能有人可以帮我如何正确取消订阅Observable？
我的应用程序中有一个表格视图.我使用以下代码为此表生成了数据源
struct ContactNameNumberBlockStatus {
var contactThumbnail: Data?
var contactName : String
var contactNumber: String
var blockStatus : Bool
}
class BlockListTableViewCell: UITableViewCell {
@IBOutlet weak var contactImage: UIImageView!
@IBOutlet weak var contactName: UILabel!
@IBOutlet weak var contactNumber: UILabel!
@IBOutlet weak var blockButton: UIButton!
var eachCell : ContactNameNumberBlockStatus! {
didSet {
// setting ui
}
}
}
private func showTableContent(data : Observable<[ContactNameNumberBlockStatus]>) {
data.bindTo(tableView.rx.items(
cellIdentifier: "BlockListTableViewCell")) {
row, contributor, cell in
if let cell2 = cell as? BlockListTableViewCell {
cell2.eachCell = …如何通过编程更改UITextField文本属性获得信号？通过使用rx.text仅在用户通过键盘输入文本时报告信号.如果以编程方式设置textField.text,则不会触发信号.
这就是我使用rx.text的方式
(self.phoneNumberTextField.rx.text).orEmpty.subscribe(onNext: { [weak self] (phone) in
// do something
}).addDisposableTo(disposeBag)
self.phoneNumberTextField.text = "this is for test"
谢谢!
RX的实现提供BehaviorSubject<T>和Variable<T>作为随时间变化的建模特性机制(C#INotifyPropertyChanged的一种有用的替代品).
通常这些都是暴露的,Observable<T>但是将属性公开为更有用:
class ObservableValue<T> : Observable<T>{
var currentValue:T { get }
}
这可以在swift中沿着这些行创建:
class ObservableValue<Element> : ObservableType {
typealias E = Element
private let subject:BehaviorSubject<E>
var currentValue:E {
get {
return try! subject.value()
}
}
init(subject:BehaviorSubject<E>) {
self.subject = subject
}
func subscribe<O: ObserverType where O.E == E>(observer: O) -> Disposable {
return self.subject.subscribe(observer)
}
}
这已经存在了吗？如果不是因为它违背了Rx的目标？
围绕它的唯一方法是公开一个单独的currentValue或写消费者,假设暴露的Observable背后的具体实现是BehaviourSubject或链中的某个地方发生了重放(),例如以下代码片段并未明确表示当我订阅时,我会得到一个值:
class MyViewModel {
// 'I will notify you of changes perhaps including my current value'
myProperty:Observable<String> …我为1 UIButton订阅了2次:
码:
class ProductionSize {
var id : Int?
var size: Int = 0
var name: String = ""
}
class ProductionCell: UICollectionViewCell {
var rxBag = DisposeBag()
// this will be set in the (cellForItemAt indexPath: IndexPath) of collection view
var productionSize: ProductionSize? {
didSet {
showProductionSize()
prepareButton()
}
}
func showProductionSize() {
// ... code for showing ProductionSize in labels
}
func prepareButton() {
// This for subscribing for every click for displaying purpose
btn_increase.rx.tap …我是反应式编程的新手,这是我正在尝试的
.驾驶
searchController.rx.text
.asDriver()
.drive(onNext: { (element) in
print(element)
}).disposed(by: disposeBag)
.订阅
searchController.rx.text
.asObservable()
.subscribe(onNext: { (element) in
print(element)
}).disposed(by: disposeBag)
这两个区块的工作完全一样,什么是使用的目的.drive了.subscribe？在这情况下,我们应该使用.drive过.subscribe？
任何帮助将不胜感激