Alamofire-Response

一、Response

1、Response: 信息保存者，面向对象

        SessionManager.default
            .request(urlString)
            .response { (response) in
                print("原始数据: \(response)")
        }

• 点击response

extension DataRequest {
    @discardableResult
    public func response(queue: DispatchQueue? = nil, completionHandler: @escaping (DefaultDataResponse) -> Void) -> Self {
        delegate.queue.addOperation {
            (queue ?? DispatchQueue.main).async {
                var dataResponse = DefaultDataResponse(
                    request: self.request,
                    response: self.response,
                    data: self.delegate.data,
                    error: self.delegate.error,
                    timeline: self.timeline
                )

                dataResponse.add(self.delegate.metrics)

                completionHandler(dataResponse)
            }
        }

        return self
    }
}

• 点击self.delegate.data

    override var data: Data? {
        if dataStream != nil {
            return nil
        } else {
            return mutableData
        }
    }

• mutableData.append(data) 代理回调回来往mutableData中添加数据

    func urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive data: Data) {
        if initialResponseTime == nil { initialResponseTime = CFAbsoluteTimeGetCurrent() }

        if let dataTaskDidReceiveData = dataTaskDidReceiveData {
            dataTaskDidReceiveData(session, dataTask, data)
        } else {
            if let dataStream = dataStream {
                dataStream(data)
            } else {
                mutableData.append(data)
            }

            let bytesReceived = Int64(data.count)
            totalBytesReceived += bytesReceived
            let totalBytesExpected = dataTask.response?.expectedContentLength ?? NSURLSessionTransferSizeUnknown

            progress.totalUnitCount = totalBytesExpected
            progress.completedUnitCount = totalBytesReceived

            if let progressHandler = progressHandler {
                progressHandler.queue.async { progressHandler.closure(self.progress) }
            }
        }
    }

2、DefaultDataResponse和DataResponse的区别
DataResponse再封装了一层，序列化层

二、序列化

1、自定义序列化

        let dyzResponseSerilizer = DataResponseSerializer<String>.init { (request, response, data, error) -> Result<String> in
            print("原始数据2: \(response!)")
            return .success("dyz_DataResponseSerializer_dyz")
        }

        SessionManager.default
            .request(urlString)
            .response { (response) in
                print("原始数据1: \(response)")
            }
            .response(responseSerializer: dyzResponseSerilizer) { (dyzDataResponse) in
                print("序列化之后：\(dyzDataResponse)")
        }

• 点击responseSerializer
• responseSerializer.serializeResponse( self.request, self.response, self.delegate.data, self.delegate.error )执行闭包，dyzResponseSerilizer初始化时候的闭包

extension DataRequest {
    @discardableResult
    public func response<T: DataResponseSerializerProtocol>(
        queue: DispatchQueue? = nil,
        responseSerializer: T,
        completionHandler: @escaping (DataResponse<T.SerializedObject>) -> Void)
        -> Self
    {
        delegate.queue.addOperation {
            let result = responseSerializer.serializeResponse(
                self.request,
                self.response,
                self.delegate.data,
                self.delegate.error
            )

            var dataResponse = DataResponse<T.SerializedObject>(
                request: self.request,
                response: self.response,
                data: self.delegate.data,
                result: result,
                timeline: self.timeline
            )

            dataResponse.add(self.delegate.metrics)

            (queue ?? DispatchQueue.main).async { completionHandler(dataResponse) }
        }

        return self
    }
}

2、Data、String、JSON、Property List

       SessionManager.default
            .request(urlString)
            .responseJSON { (response) in
                print(response)
        }

• 点击responseJSON

extension DataRequest {
    public static func jsonResponseSerializer(
        options: JSONSerialization.ReadingOptions = .allowFragments)
        -> DataResponseSerializer<Any>
    {
        return DataResponseSerializer { _, response, data, error in
            return Request.serializeResponseJSON(options: options, response: response, data: data, error: error)
        }
    }

    @discardableResult
    public func responseJSON(
        queue: DispatchQueue? = nil,
        options: JSONSerialization.ReadingOptions = .allowFragments,
        completionHandler: @escaping (DataResponse<Any>) -> Void)
        -> Self
    {
        return response(
            queue: queue,
            responseSerializer: DataRequest.jsonResponseSerializer(options: options),
            completionHandler: completionHandler
        )
    }
}

• 点击serializeResponseJSON

extension Request {
    public static func serializeResponseJSON(
        options: JSONSerialization.ReadingOptions,
        response: HTTPURLResponse?,
        data: Data?,
        error: Error?)
        -> Result<Any>
    {
        guard error == nil else { return .failure(error!) }

        if let response = response, emptyDataStatusCodes.contains(response.statusCode) { return .success(NSNull()) }

        guard let validData = data, validData.count > 0 else {
            return .failure(AFError.responseSerializationFailed(reason: .inputDataNilOrZeroLength))
        }

        do {
            let json = try JSONSerialization.jsonObject(with: validData, options: options)
            return .success(json)
        } catch {
            return .failure(AFError.responseSerializationFailed(reason: .jsonSerializationFailed(error: error)))
        }
    }
}