AlamofireObjectMapper
Alamofire 的一个扩展，它使用 ObjectMapper 自动将 JSON 响应数据转换为 Swift 对象。
用法
给定一个返回以下格式的天气数据的 URL
{
"location": "Toronto, Canada",
"three_day_forecast": [
{
"conditions": "Partly cloudy",
"day" : "Monday",
"temperature": 20
},
{
"conditions": "Showers",
"day" : "Tuesday",
"temperature": 22
},
{
"conditions": "Sunny",
"day" : "Wednesday",
"temperature": 28
}
]
}
您可以使用扩展如下使用
import AlamofireObjectMapper
let URL = "https://raw.githubusercontent.com/tristanhimmelman/AlamofireObjectMapper/d8bb95982be8a11a2308e779bb9a9707ebe42ede/sample_json"
Alamofire.request(URL).responseObject { (response: DataResponse<WeatherResponse>) in
let weatherResponse = response.result.value
print(weatherResponse?.location)
if let threeDayForecast = weatherResponse?.threeDayForecast {
for forecast in threeDayForecast {
print(forecast.day)
print(forecast.temperature)
}
}
}完战处理程序中的 WeatherResponse 对象是您定义的自定义对象。唯一的要求是对象必须遵守 ObjectMapper 的 Mappable 协议。在上面的例子中，WeatherResponse 对象看起来如下
import ObjectMapper
class WeatherResponse: Mappable {
var location: String?
var threeDayForecast: [Forecast]?
required init?(map: Map){
}
func mapping(map: Map) {
location <- map["location"]
threeDayForecast <- map["three_day_forecast"]
}
}
class Forecast: Mappable {
var day: String?
var temperature: Int?
var conditions: String?
required init?(map: Map){
}
func mapping(map: Map) {
day <- map["day"]
temperature <- map["temperature"]
conditions <- map["conditions"]
}
}此扩展使用泛型允许您创建自己的自定义响应对象。下面是 responseObject 函数定义。只需将 T 替换为您的自定义响应对象，并扩展处理其余部分
public func responseObject<T: BaseMappable>(queue: DispatchQueue? = nil, keyPath: String? = nil, mapToObject object: T? = nil, context: MapContext? = nil, completionHandler: @escaping (DataResponse<T>) -> Void) -> Self此 responseObject 函数有 4 个可选参数和一个必需的完战处理程序
queue：完战处理程序分发的队列。keyPath：对象映射应该执行的 JSON 的键路径。mapToObject：在它上面执行映射的对象。context：传递给映射函数的 上下文 对象。completionHandler：在请求完成并由 ObjectMapper 映射数据后执行的闭包。
嵌套对象的简单映射
AlamofireObjectMapper 支持在键中使用点符号来简化嵌套对象的映射。以下是一个 JSON 字符串示例
"distance" : {
"text" : "102 ft",
"value" : 31
}您可以按如下方式访问嵌套对象
func mapping(map: Map) {
distance <- map["distance.value"]
}键路径
keyPath 变量用于深入 JSON 响应，并只映射在此 keyPath 找到的数据。它支持像 data.weather 这样的嵌套值，以在 JSON 响应中深入多个级别。
let URL = "https://raw.githubusercontent.com/tristanhimmelman/AlamofireObjectMapper/2ee8f34d21e8febfdefb2b3a403f18a43818d70a/sample_keypath_json"
let expectation = expectationWithDescription("\(URL)")
Alamofire.request(URL).responseObject(keyPath: "data") { (response: DataResponse<WeatherResponse>) in
expectation.fulfill()
let weatherResponse = response.result.value
print(weatherResponse?.location)
if let threeDayForecast = weatherResponse?.threeDayForecast {
for forecast in threeDayForecast {
print(forecast.day)
print(forecast.temperature)
}
}
}数组响应
如果您有一个返回数据为 Array 格式的端点，您可以使用以下函数将其映射
public func responseArray<T: Mappable>(queue queue: dispatch_queue_t? = nil, keyPath: String? = nil, completionHandler: DataResponse<[T]> -> Void) -> Self例如，如果您的端点返回以下数据
[
{
"conditions": "Partly cloudy",
"day" : "Monday",
"temperature": 20
},
{
"conditions": "Showers",
"day" : "Tuesday",
"temperature": 22
},
{
"conditions": "Sunny",
"day" : "Wednesday",
"temperature": 28
}
]
您可以这样请求和映射它
let URL = "https://raw.githubusercontent.com/tristanhimmelman/AlamofireObjectMapper/f583be1121dbc5e9b0381b3017718a70c31054f7/sample_array_json"
Alamofire.request(URL).responseArray { (response: DataResponse<[Forecast]>) in
let forecastArray = response.result.value
if let forecastArray = forecastArray {
for forecast in forecastArray {
print(forecast.day)
print(forecast.temperature)
}
}
}
安装
您可以使用 CocoaPods 将 AlamofireObjectMapper 添加到项目中，方法是在您的 Podfile 中添加以下行
pod 'AlamofireObjectMapper', '~> 5.2'
如果您使用的是 Carthage，您可以通过将其添加到您的 Cartfile 来添加对 AlamofireObjectMapper 的依赖
github "tristanhimmelman/AlamofireObjectMapper" ~> 5.2