在创建可观察对象数组后在 RxSwift 中使用 zip 运算符

Question

我有一个 newBid 对象，其中包含一些数据和图像数组。我想将所有图像和数据上传到服务器，然后 zip 那些上传可观察对象。如果我为 data、image1 和 image2 创建单独的 drivers，我就成功了。

但我真正想做的是不对图像进行硬编码，因为数组可能包含 0 到 10 张图像。我想以编程方式创建 observables 数组并 zip 它们。

let dataSaved = saveTaps.withLatestFrom(newBid)
    .flatMapLatest { bid in
        return CustomerManager.shared.bidCreate(bid: bid)
            .trackActivity(activityIndicator)
            .asDriver(onErrorJustReturn: false)
}

let photoSaved0 = saveTaps.withLatestFrom(newBid)
    .flatMapLatest { bid in
        return CustomerManager.shared.bidUploadFile(image: bid.images[0])
            .trackActivity(activityIndicator)
            .asDriver(onErrorJustReturn: false)
}

let photoSaved1 = saveTaps.withLatestFrom(newBid)
    .flatMapLatest { bid in
        return CustomerManager.shared.bidUploadFile(image: bid.images[1])
            .trackActivity(activityIndicator)
            .asDriver(onErrorJustReturn: false)
}

saveCompleted = Driver.zip(dataSaved, photoSaved0, photoSaved1){ return [=10=] &&  &&  }

/*
// 0. Getting array of images from newBid
let images = newBid.map { bid in
    return bid.images
}

// 1. Creating array of upload drivers from array of images
let imageUploads = images.map { (images: [UIImage]) -> [Driver<Bool>] in
    var temp = [Driver<Bool>]()
    return temp
}

// 2. Zipping array of upload drivers to photoSaved driver
photoSaved = Driver
    .zip(imageUploads) // wait for all image requests to finish
    .subscribe(onNext: { results in
        // here you have every single image in the 'images' array
        results.forEach { print([=10=]) }
    })
    .disposed(by: disposeBag)*/

在评论部分，如果我尝试 zip imageUploads，我会收到错误消息：

Argument type 'SharedSequence<DriverSharingStrategy, [SharedSequence<DriverSharingStrategy, Bool>]>' does not conform to expected type 'Collection'

Answer 1

最终解决方案

let bidID: Driver<Int> = saveTaps.withLatestFrom(newBid)
    .flatMapLatest { bid in
        return CustomerManager.shared.bidCreate(bid: bid)
            .trackActivity(activityIndicator)
            .asDriver(onErrorJustReturn: 0)
}

saveCompleted = Driver.combineLatest(bidID, newBid) { bidID, newBid in
    newBid.uploadedImages.map {
        CustomerManager.shared.bidUploadFile(image: [=10=], bidID: bidID).asDriver(onErrorJustReturn: false)
    }
    }.flatMap { imageUploads in
        return Driver.zip(imageUploads).trackActivity(activityIndicator).asDriver(onErrorJustReturn: [])
    }.map{ (results:[Bool]) -> Bool in
        return !results.contains(false)
}

它是这个的组合版本，等效于：

let imageUploads: Driver<[Driver<Bool>]> = Driver.combineLatest(bidID, newBid) { bidID, newBid in
    newBid.uploadedImages.map {
        CustomerManager.shared.bidUploadFile(image: [=11=], bidID: bidID).asDriver(onErrorJustReturn: false)
    }
}

let photosSaved: Driver<[Bool]> = imageUploads.flatMap { imageUploads in
    return Driver.zip(imageUploads).trackActivity(activityIndicator).asDriver(onErrorJustReturn: [])
}

saveCompleted = photosSaved.map{ (results:[Bool]) -> Bool in
    return !results.contains(false)
}

Answer 2

这样的怎么样？

let saves = saveTaps.withLatestFrom(newBid)
    .flatMapLatest { (bid: Bid) -> Observable<[Bool]> in
        let dataSaved = CustomerManager.shared.bidCreate(bid: bid)
            .catchErrorJustReturn(false)

        let photosSaved = bid.images.map {
            CustomerManager.shared.bidUploadFile(image: [=10=], bidID: bid.id)
                .catchErrorJustReturn(false)
        }

        return Observable.zip([dataSaved] + photosSaved)
            .trackActivity(activityIndicator)
    }
    .asDriver(onErrorJustReturn: []) // remove this line if you want an Observable<[Bool]>.

在创建可观察对象数组后在 RxSwift 中使用 zip 运算符

Using zip operator in RxSwift after creating an array of observables

ios

swift

rx-swift

rx-cocoa