优雅的网络请求Moya

最近在看swift，看到Moya在网络请求封装这一块儿做的非常好。
具体优点:
1.模块化封装，可以按具体的业务划分成模块，业务逻辑清晰，可维护性强；
2.统一配置，可以配置共同的参数值；
3.解耦，根据不同的请求枚举类型返回不同的请求参数.

下面看一下Moya给出的Demo, 这是一个GitHub Api的封装:

//JSON数据解析
private func JSONResponseDataFormatter(_ data: Data) -> Data {
    do {
        let dataAsJSON = try JSONSerialization.jsonObject(with: data)
        let prettyData =  try JSONSerialization.data(withJSONObject: dataAsJSON, options: .prettyPrinted)
        return prettyData
    } catch {
        return data // fallback to original data if it can't be serialized.
    }
}

//初始化请求类
let gitHubProvider = MoyaProvider<GitHub>(plugins: [NetworkLoggerPlugin(verbose: true, responseDataFormatter: JSONResponseDataFormatter)])

//String的拓展
private extension String {
    var urlEscaped: String {
        return self.addingPercentEncoding(withAllowedCharacters: .urlHostAllowed)!
    }
}

//按照业务声明接口枚举，非常清晰
public enum GitHub {
    case zen
    case userProfile(String)
    case userRepositories(String)
}

//网络请求配置
extension GitHub: TargetType {
    //baseUrl
    public var baseURL: URL { return URL(string: "https://api.github.com")! }
    //根据不同业务返回请求路由
    public var path: String {
        switch self {
        case .zen:
            return "/zen"
        case .userProfile(let name):
            return "/users/\(name.urlEscaped)"
        case .userRepositories(let name):
            return "/users/\(name.urlEscaped)/repos"
        }
    }
    
    //设置请求类型，可根据不同也去设置不同的类型
    public var method: Moya.Method {
        return .get
    }
    public var task: Task {
        switch self {
        case .userRepositories:
            return .requestParameters(parameters: ["sort": "pushed"], encoding: URLEncoding.default)
        default:
            return .requestPlain
        }
    }
    
    //验证类型
    public var validationType: ValidationType {
        switch self {
        case .zen:
            return .successCodes
        default:
            return .none
        }
    }
    
    //mock的数据
    public var sampleData: Data {
        switch self {
        case .zen:
            return "Half measures are as bad as nothing at all.".data(using: String.Encoding.utf8)!
        case .userProfile(let name):
            return "{\"login\": \"\(name)\", \"id\": 100}".data(using: String.Encoding.utf8)!
        case .userRepositories(let name):
            return "[{\"name\": \"\(name)\"}]".data(using: String.Encoding.utf8)!
        }
    }
    
    //请求头
    public var headers: [String: String]? {
        return nil
    }
}

//拼接成完整的请求URL
public func url(_ route: TargetType) -> String {
    return route.baseURL.appendingPathComponent(route.path).absoluteString
}

//返回值拓展
extension Moya.Response {
    func mapNSArray() throws -> NSArray {
        let any = try self.mapJSON()
        guard let array = any as? NSArray else {
            throw MoyaError.jsonMapping(self)
        }
        return array
    }
}

发起请求

        gitHubProvider.request(.userRepositories(username)) { result in
            do {
                let response = try result.dematerialize()
                let value = try response.mapNSArray()
            } catch {
                let printableError = error as CustomStringConvertible
            }
        }

返回结果

请求结果