基於Moya、RxSwift和ObjectMapper實現REST API請求
阿新 • • 發佈：2019-12-25
在Android開發中有非常強大的 Retrofit 請求，結合RxJava可以非常方便實現 RESTful API 網路請求。在 iOS開發中也有非常強大的網路請求庫 Moya ，Moya是一個基於 Alamofire 開發的,輕量級的Swift網路層。Moya的可擴充套件性非常強,可以方便和RXSwift、ObjectMapper結合。
測試 REST API 定義
我們先用服務端定義幾個REST API，開發者根據自己的條件來實現。
請求錯誤格式例項
{
"error": "密碼錯誤","error_code": "password_error"
}複製程式碼測試 API 列表
- http://127.0.0.1:8080/account/login，引數username、password，post請求，成功響應為User。
- http://127.0.0.1:8080/user/{userId}，get請求，成功響應為User。
- http://127.0.0.1:8080/user/query?q={keyword}，get請求，成功響應為User列表。
建立介面
// MyApiService.swift
import Moya
enum MyApiService {
case login(username:String,password:String)
case user(userId:String)
case 請求資料
let provider = MoyaProvider<MyApiService>()
// Moya 提供最原始的請求方式，響應的資料是二進位制
provider.request(.user(userId: "101")){ result in
// do something with the result
let text = String(bytes: result.value!.data,encoding: .utf8)
print("text1 = \(text)")
}
// 結合RxSwift，響應的資料是二進位制
provider.rx.request(.user(userId: "101")).subscribe({result in
// do something with the result
switch result {
case let .success(response):
let text = String(bytes: response.data,encoding: .utf8)
print("text2 = \(text)")
case let .error(error):
print(error)
}
})
// 通過mapJSON把資料轉換成json格式
provider.rx.request(.user(userId: "101")).mapJSON().subscribe({result in
// do something with the result
switch result {
case let .success(text):
print("text3 = \(text)")
case let .error(error):
print(error)
}
})
// 通過mapJSON把資料轉換成json格式，並轉換成最常見的Observable
provider.rx.request(.user(userId: "101")).mapJSON().asObservable().subscribe(onNext: { result in
// do something with the result
print("text4 = \(result)")
},onError:{ error in
// do something with the error
})複製程式碼請求資料：RxBlocking
RxBlocking使用教程 ，可以使用同步的方式請求網路
import RxBlocking
do{
let text = try provider.rx.request(.user(userId: "101")).mapJSON().toBlocking().first()
print("text5 = \(text)")
}catch{
print(error)
}複製程式碼結合 ObjectMapper
引入ObjectMapper
pod 'ObjectMapper','~> 3.4'複製程式碼編寫RxSwift拓展程式碼
// MoyaRxSwiftObjectMapperExtension.swift
import Foundation
import RxSwift
import Moya
import ObjectMapper
public extension PrimitiveSequence where TraitType == SingleTrait,ElementType == Response {
func mapObject<T: BaseMappable>(type: T.Type) -> Single<T> {
return self.map{ response in
return try response.mapObject(type: type)
}
}
func mapArray<T: BaseMappable>(type: T.Type) -> Single<[T]> {
return self.map{ response in
return try response.mapArray(type: type)
}
}
}
public extension ObservableType where E == Response {
func mapObject<T: BaseMappable>(type: T.Type) -> Observable<T> {
return self.map{ response in
return try response.mapObject(type: type)
}
}
func mapArray<T: BaseMappable>(type: T.Type) -> Observable<[T]> {
return self.map{ response in
return try response.mapArray(type: type)
}
}
}
public extension Response{
func mapObject<T: BaseMappable>(type: T.Type) throws -> T{
let text = String(bytes: self.data,encoding: .utf8)
if self.statusCode < 400 {
return Mapper<T>().map(JSONString: text!)!
}
do{
let serviceError = Mapper<ServiceError>().map(JSONString: text!)
throw serviceError!
}catch{
if error is ServiceError {
throw error
}
let serviceError = ServiceError()
serviceError.message = "伺服器開小差，請稍後重試"
serviceError.error_code = "parse_error"
throw serviceError
}
}
func mapArray<T: BaseMappable>(type: T.Type) throws -> [T]{
let text = String(bytes: self.data,encoding: .utf8)
if self.statusCode < 400 {
return Mapper<T>().mapArray(JSONString: text!)!
}
do{
let serviceError = Mapper<ServiceError>().map(JSONString: text!)
throw serviceError!
}catch{
if error is ServiceError {
throw error
}
let serviceError = ServiceError()
serviceError.message = "伺服器開小差，請稍後重試"
serviceError.error_code = "parse_error"
throw serviceError
}
}
}
class ServiceError:Error,Mappable{
var message:String = ""
var error_code:String = ""
required init?(map: Map) {}
init() {
}
func mapping(map: Map) {
error_code <- map["error_code"]
message <- map["error"]
}
var localizedDescription: String{
return message
}
}
複製程式碼建立 User 類
// User.swift
import ObjectMapper
class User: Mappable {
required init?(map: Map) {}
func mapping(map: Map) {
userId <- map["userId"]
name <- map["name"]
age <- map["age"]
}
var userId:Int = 0
var name:String = ""
var age:Int = 0
}複製程式碼測試
do{
let user = try provider.rx.request(.user(userId: "101")).mapObject(type: User.self).toBlocking().first()
print("user.name = \(user?.name)")
}catch{
print(error)
}
do{
let user = try provider.rx.request(.user(userId: "101")).asObservable().mapObject(type: User.self).toBlocking().first()
print("user.name = \(user?.name)")
}catch{
print(error)
}
do{
let users = try provider.rx.request(.userQuery(keyword: "Wiki")).mapArray(type: User.self).toBlocking().first()
print("test8 users.count = \(users?.count)")
}catch{
if error is ServiceError {
print((error as! ServiceError).message)
}
print(error)
}複製程式碼列印日誌
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.
}
}複製程式碼let provider = MoyaProvider<MyApiService>(plugins: [NetworkLoggerPlugin(verbose: true,responseDataFormatter: JSONResponseDataFormatter)])複製程式碼