ios - Reduce 或 Flatmap json 对单个数组的响应

Question

我有一个 json 消息响应正文，如下所示。就我的 UI 而言，顶级消息只是列表中的第一条消息。

{
    "messageId": "1234-1234-1234",
    "jobId": "1234-1234-1234",
    "message": "This is the top level message",
    "createdDate": "2019-03-18T14:55:21.467",
    "user": {},
    "messages": [{
            "messageId": "1234-1234-1234",
            "jobId": "1234-1234-1234",
            "message": "This is the a child message",
            "createdDate": "2019-03-18T14:55:21.467",
            "user": {},
            "messages": [],
            "attachments": []
        },
        {
            "messageId": "1234-1234-1234",
            "jobId": "1234-1234-1234",
            "message": "This is the another child message",
            "createdDate": "2019-03-18T14:55:21.467",
            "user": {},
            "messages": [],
            "attachments": []
        },
        {
            "messageId": "1234-1234-1234",
            "jobId": "1234-1234-1234",
            "message": "This is the yet another child message",
            "createdDate": "2019-03-18T14:55:21.467",
            "user": {},
            "messages": [],
            "attachments": []
        }
    ],
    "attachments": []
}

服务器实体

struct MessageServer: Codable {
let messageId: String
let jobId: String
let message: String
let createdDate: Date
let user: User
let messages: [MessageServer]
let attachments: [FileServer]

init(messageId: String,
     jobId: String,
     message: String,
     createdDate: Date,
     user: User,
     messages: [MessageServer],
     attachments: [FileServer]
    ) {

    self.messageId = messageId
    self.jobId = jobId
    self.message = message
    self.createdDate = createdDate
    self.user = user
    self.messages = messages
    self.attachments = attachments
}

应用实体

struct Message: Codable {
let message: String
let createdDate: Date
let displayName: String
let isMine: Bool
let attachments: [File]

init(message: String, createdDate: Date, displayName: String, isMine: Bool, attachments: [File]) {
    self.message = message
    self.createdDate = createdDate
    self.displayName = displayName
    self.isMine = isMine
    self.attachments = attachments
}

在我的服务调用中，我只想返回一个 Observable 消息数组。

func getMessages(sectionID id: String) -> Observable<[Message]> {
    return messageServiceEndpoints
        .getMessages(for: id)
        .map({
            $0.map({
                Message( /* init message here */ )
             })
         })
}

有没有办法将其缩减或平面化为单个数组？

Answer 1

这不是真正的 RxSwift 问题...您只需要解析 JSON:

struct Message: Decodable {
    let messageId: String
    let message: String
    let createdDate: Date
    private (set) var messages: [Message]
    // and the rest...

    var droppedMessages: Message {
        var result = self
        result.messages = []
        return self
    }
}

func parseMessages(from data: Data) throws -> [Message] {
    let dateFormatter = DateFormatter()
    dateFormatter.dateFormat = "yyy-MM-dd'T'HH:mm:ss.SSS"
    let decoder = JSONDecoder()
    decoder.dateDecodingStrategy = .formatted(dateFormatter)
    let response = try decoder.decode(Message.self, from: data)
    return [response.droppedMessages] + response.messages
}