Question

我是Reactive Programming的新手，我有一个很大的问题，我不能单独解决......我需要上传几个视频资产并按顺序上传，但我不知道该怎么做它，我有一组PHAssets，我试图通过每个元素迭代并通过网络发送它这是我的代码到目前为止的评论：

for item in items {
                    let fileName = item.media.localIdentifier

                    //Observable to generate local url to be used to save the compressed video
                    let compressedVideoOutputUrl = videoHelper.getDocumentsURL().appendingPathComponent(fileName)

                    //Observable to generate a thumbnail image for the video
                    let thumbnailObservable =  videoHelper.getBase64Thumbnail(myItem: item)

                    //Observable to request the video from the iPhone library
                    let videoObservable = videoHelper.requestVideo(myItem: item)

                        //Compress the video and save it on the previously generated local url
                        .flatMap { videoHelper.compressVideo(inputURL: $0, outputURL: compressedVideoOutputUrl) }
                    //Generate the thumbnail and share the video to send over the network
                    let send = videoObservable.flatMap { _ in thumbnailObservable }
                        .flatMap { api.uploadSharedFiles(item, filename: fileName, base64String: $0) }

                    //subscribe the observable
                    send.subscribe(onNext: { data in
                        print("- Done chain sharing Video -")
                    },
                                   onError: { error in
                                    print("Error sharing Video-> \(error.localizedDescription)")
                    }).disposed(by: actionDisposeBag)

                }

Answer 1

如果要在flatMap中逐个上传项目，请使用枚举

编辑：枚举在您需要知道元素的索引时很有用，否则只有flatMap一个参数就可以了。

Observable.from(items)
    .enumerated()
    .flatMap() { index, item -> Observable<Item> in
        return uploadItem(item)
    }
    .subscribe(onNext: { print($0) })
    .disposed(by: disposeBag)

Answer 2

使用集合元素和 .flatMap（）对现有代码进行观察 -

const argv = require('minimist')(process.argv.slice(2));
const csv = argv.file;

循环使用RxSwift

2 个答案: