如何在Swift 4-5中使用Structs和Decodable从API中提取信息? [英] How to extract information from API using Structs and Decodable in Swift 4-5?
本文介绍了如何在Swift 4-5中使用Structs和Decodable从API中提取信息?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我需要使用openweather网站从json中提取信息.但是我在从天气"(以及任何其他)部分提取信息时遇到了问题(我需要主要"和描述").我到目前为止只能提取坐标(坐标").但是如上所述，我一直坚持要获取天气"部分.我还尝试获取"sys"部分来获取"sunrise"和"sunset"变量，但出现错误.
I need to extract information from the a json using the openweather website. But I have problems on extracting the information from the "weather" (and any other) part (I need "main" and "description"). I was able to extract (so far) only the coordinates ("coord"). But I'm stuck to get the "weather" section as I mentioned above. I also tried to get the "sys" part to get the "sunrise" and "sunset" variables but I get an error.
我已经可以使用警卫队让"方法来获取所有这些信息，但是现在我想使用可解码的结构"方法来获取它.使用结构可解码"方法，我只能从API中获取坐标，但是如果尝试在结构中添加任何其他元素，则表示类型'元素'不符合协议'可解码'" .我在这里被卡住了.如果在结构Elements:Decodable中删除//，则会收到上述错误.
I have been capable of getting all of this information using the "guard let" method but now I would like to get it using the "struct decodable" method. Using the "struct decodable" method, I am able to get only the coordinates from the API, but if I try to add any other element in the struct, it says that "Type 'Elements' does not conform to protocol 'Decodable'". It is here were I get stuck. If I remove the // in the struct Elements:Decodable I get the error mentioned above.
这是我目前的代码:
import UIKit
import CoreLocation
//MARK: - Structures to parse the JSON in the Openweather API.
struct Elements:Decodable {
let coord:[String:Double]
// let weather:[String:Any]
// let sys:[String:Any]
}
//MARK: Class ViewController
class ViewController: UIViewController {
//MARK: Method viewDidLoad()
override func viewDidLoad() {
super.viewDidLoad()
let jsonURL = "some URL that I can't provide you guys since it has a private key that I can't share, sorry :C "
guard let url = URL(string: jsonURL) else{return}
URLSession.shared.dataTask(with: url) { (data, response, err) in
guard let data = data else{return}
do{
let weather = try JSONDecoder().decode(Elements.self, from: data)
print("Coordinates: ", weather.coord)
print("Longitude: ", weather.coord["lon"]!)
print("Latitude: ", weather.coord["lat"]!)
print("Weather: ", weather.weather)
}catch let jsonErr{
print("Error serializing Json: ", jsonErr)
}
}.resume()
}
}
这是JSON:
{
"coord":
{"lon":-3.74,"lat":40.39},
"weather":
[
{
"id":800,
"main":"Clear",
"description":"clear sky",
"icon":"01d"
}
],
"base":"stations",
"main":
{
"temp":291.47,
"pressure":1027,
"humidity":42,
"temp_min":290.37,
"temp_max":293.15
},
"visibility":10000,
"wind":
{
"speed":1.5
},
"clouds":
{
"all":0
},
"dt":1556368766,
"sys":
{
"type":1,
"id":6443,
"message":0.0065,
"country":"ES",
"sunrise":1556342391,
"sunset":1556391910},
"id":6355233,
"name":"Provincia de Madrid",
"cod":200
}
我尝试打印结果，但得到类型'Elements'不符合协议'Decodable'".
I try to print the results but I get "Type 'Elements' does not conform to protocol 'Decodable'".
推荐答案
在这里，我分享3种可能的选择(使用"if let"，"guard let"和"Codable").
Here I share 3 possible options (using "if let", using "guard let" and using "Codable").
如果使用let方法:
class ViewController: UIViewController {
// MARK: - Variables and constants
var DNI = [Double](repeating: 0.0, count: 12)
var DHI = [Double](repeating: 0.0, count: 12)
var GHI = [Double](repeating: 0.0, count: 12)
// MARK: - Method viewDidLoad()
override func viewDidLoad() {
super.viewDidLoad()
// MARK: Open Weather API
if let urlJSONOpenWeather = URL(string: "http://api.openweathermap.org/data/2.5/weather?lat=51.9946&lon=4.378799&appid=get_api_id_for_openweather"){
let OpenWeatherTask = URLSession.shared.dataTask(with: urlJSONOpenWeather) { (data, response, error) in
if error == nil{
if let urlContent = data{
do {
let jsonResult = try JSONSerialization.jsonObject(with: urlContent, options: JSONSerialization.ReadingOptions.mutableContainers) as! [String:Any]
print("This is jsonResult: ", jsonResult)
print("---------------------")
if let coordinates = (jsonResult["coord"] as? NSDictionary), let longitude = coordinates["lon"] as? NSNumber, let latitude = coordinates["lat"] as? NSNumber{
print("Longitude: \(longitude)º")
print("Latitude: \(latitude)º")
print("---------------------")
}
if let weatherData = (jsonResult["weather"] as? Array<[String:Any]>){
print("Weather data array: \(weatherData)")
print("Weather id: ", weatherData[0]["id"]!)
print("Weather main: ", weatherData[0]["main"]!)
print("Weather description: ", weatherData[0]["description"]!)
print("Weather icon: ", weatherData[0]["icon"]!)
print("---------------------")
}
if let mainValues = (jsonResult["main"] as? NSDictionary), let temperatureK = mainValues["temp"] as? NSNumber, let pressure = mainValues["pressure"] as? NSNumber, let humidity = mainValues["humidity"] as? NSNumber{
print("Temperature in Kelvin: \(temperatureK) K")
let tempKString = (temperatureK as AnyObject).description
var tempCelsius = (tempKString! as NSString).floatValue
tempCelsius = tempCelsius - 273.15
print("Temperature in Celsius: \(String(format:"%.2f", tempCelsius))ºC")
print("Pressure: \(pressure) hPa")
print("Humidity: \(humidity)%")
print("---------------------")
}
if let wind = (jsonResult["wind"] as? NSDictionary)? ["speed"]{
print("Wind speed: \(wind) m/s")
print("---------------------")
}
if let sysData = (jsonResult["sys"] as? NSDictionary), let country = sysData["country"] as? NSString, let sunriseValue = sysData["sunrise"] as? NSNumber, let sunsetValue = sysData["sunset"] as? NSNumber{
print("Country code: \(country)")
//Give a format to the time
let formatter = DateFormatter()
formatter.dateStyle = .none
formatter.timeStyle = .medium
formatter.dateFormat = "HH:mm:ss"
//First we get the sunrise time.
let sunriseDate = Date(timeIntervalSince1970: sunriseValue.doubleValue)
print("Sunrise date: \(sunriseDate)")
let sunrise = formatter.string(from: sunriseDate)
print("Sunrise: \(sunrise)")
//First we get the sunrset time.
let sunsetDate = Date(timeIntervalSince1970: sunsetValue.doubleValue)
print("Sunrise date: \(sunsetDate)")
let sunset = formatter.string(from: sunsetDate)
print("Sunset: \(sunset)")
print("---------------------")
}
}catch{
print("JSON Processing failed.")
}
}
} else {
print("Error during JSON parsing: ", error!)
}
}
OpenWeatherTask.resume()
}
if let urlJSONNASA = URL(string: "https://power.larc.nasa.gov/cgi-bin/v1/DataAccess.py?request=execute&identifier=SinglePoint¶meters=DNR,DIFF,ALLSKY_SFC_SW_DWN&userCommunity=SSE&tempAverage=CLIMATOLOGY&outputList=JSON&lat=51.994693&lon=4.378553&user=anonymous"){
let NASATask = URLSession.shared.dataTask(with: urlJSONNASA) { (data, response, error) in
if error == nil{
if let urlContent = data {
do{
let jsonResult = try JSONSerialization.jsonObject(with: urlContent, options: JSONSerialization.ReadingOptions.mutableContainers) as! [String:Any]
if let features = (jsonResult["features"] as? Array<[String:Any]>){
print("Features: ", features)
print("---------------------")
if let singleFeature = features.first {
print("Single feature: ", singleFeature)
print("---------------------")
if let geometry = singleFeature["geometry"] as? [String:Any]{
let coordinates = geometry["coordinates"] as? Array<Double>
print("Coordinates: ", coordinates!)
let nasaLon = coordinates?[0]
let nasaLat = coordinates?[1]
print("NASA Latitude: \(String(describing: nasaLat!))º | NASA Longitude: \(String(describing: nasaLon!))º")
print("---------------------")
}
if let properties = singleFeature["properties"] as? [String:Any], let parameter = properties["parameter"] as? [String:Any]{
print("Properties: ", properties)
print("Parameter: ", parameter)
let ghi_raw = parameter["ALLSKY_SFC_SW_DWN"] as? [String:Double]
print("GHI raw: ", ghi_raw!)
let dhi_raw = parameter["DIFF"] as? [String:Double]
print("DHI raw: ", dhi_raw!)
let dni_raw = parameter["DNR"] as? [String:Double]
print("DNI raw: ", dni_raw!)
print("---------------------")
// Put an order on each irradiance
for index in 1...12{
self.DNI[index - 1] = (dni_raw?[String(index)])!
self.DHI[index - 1] = (dhi_raw?[String(index)])!
self.GHI[index - 1] = (ghi_raw?[String(index)])!
}
print("DNI ordered: ", self.DNI)
print("DHI ordered: ", self.DHI)
print("GHI ordered: ", self.GHI)
print("---------------------")
}
}
}
if let parameterInformation = jsonResult["parameterInformation"] as? [String:Any]{
if let ghiDwn = parameterInformation["ALLSKY_SFC_SW_DWN"] as? [String:Any]{
print("GHI Dwn: ", ghiDwn)
print(ghiDwn["units"]!)
print(ghiDwn["longname"]!)
}
if let diffDwn = parameterInformation["DIFF"] as? [String:Any]{
print("DHI Dwn: ", diffDwn)
print(diffDwn["units"]!)
print(diffDwn["longname"]!)
}
if let dniDwn = parameterInformation["DNR"] as? [String:Any]{
print("DNI Dwn: ", dniDwn)
print(dniDwn["units"]!)
print(dniDwn["longname"]!)
}
}
print("--------------------------")
}catch{
print("Error retrieving NASA's JSON: ", error)
}
}
} else{
print("Error by retrieving the NASA's JSON: ", error!)
}
}
NASATask.resume()
}
}
}
Guard let方法:
Guard let method:
override func viewDidLoad() {
super.viewDidLoad()
// MARK: Open Weather API
guard let urlJSONOpenWeather = URL(string: "http://api.openweathermap.org/data/2.5/weather?lat=51.9946&lon=4.378799&appid=get_api_id_for_openweather")
else {
print("There was an error on retrieving the Open Weather JSON url.")
return
}
let openWeatherTask = URLSession.shared.dataTask(with: urlJSONOpenWeather) { (data, response, error) in
if error == nil{
guard let urlOpenWeatherContent = data else{ return }
print("urlOpenWeatherContent: \(urlOpenWeatherContent)")
do {
let openWeatherJSONResult = try JSONSerialization.jsonObject(with: urlOpenWeatherContent, options: JSONSerialization.ReadingOptions.mutableContainers) as! [String:Any]
print("This is the openWeatherJSONResult:\n \(openWeatherJSONResult)")
print("-----------------")
// MARK: - Extract the coordinates (latitude and longitude) from the "coord" dictionary
guard let coordinates = openWeatherJSONResult["coord"] as? [String:Any] else{
print("There was an error in 'coordinates'.")
return
}
print("These are the coordinates: ", coordinates)
print("Latitude: \(coordinates["lat"]!)º")
print("Longitude: \(coordinates["lon"]!)º")
print("-----------------")
// MARK: - Extract the weather from the an array of dictionaries
guard let weatherArray = openWeatherJSONResult["weather"] as? Array<[String:Any]> else {
print("There was an error in 'weather'.")
return
}
print("This is the 'weather' array: ", weatherArray)
print("-----------------")
guard let weather = weatherArray.first else {
print("There was an error on retrieving the elements of the 'weather' array.")
return
}
print("These are the weatherArray elements: ", weather)
print("ID: \(weather["id"]!)")
print("Main: \(weather["main"]!)")
print("Description: \(weather["description"]!)")
print("Icon: \(weather["icon"]!)")
print("-----------------")
// MARK: - Extract the atmospheric characteristics from the "main" dictionary
guard let main = openWeatherJSONResult["main"] as? [String:Double] else {
print("There was an error in 'main'.")
return
}
print("Temperature in Kelvin: \(String(main["temp"]!)) K")
let tempInCelsius = main["temp"]! - 273.15
print("Temperature in Celsius: \(String(format:"%.2f", tempInCelsius))ºC")
print("Pressure in hPa: \(String(main["pressure"]!))")
print("Humidity: \(String(main["humidity"]!)) %")
print("-----------------")
// MARK: - Extract the wind speed
guard let wind = openWeatherJSONResult["wind"] as? [String:Double] else {
print("There was an error in 'wind'.")
return
}
print("Wind speed: \(String(wind["speed"]!)) m/s")
print("-----------------")
// MARK: - Extract country, sunrise and sunset
guard let sys = openWeatherJSONResult["sys"] as? [String:Any] else {
print("There was an error in 'sys' to extract country, sunrise and sunset.")
return
}
print("Country: \(sys["country"]!)")
// First, Create a format of time for sunrise and sunset.
let formatter = DateFormatter()
formatter.dateStyle = .none
formatter.timeStyle = .medium
formatter.dateFormat = "HH:mm:ss"
// Second, determine sunrise date and get sunrise time
let sunriseValue = sys["sunrise"]
print("Type of sunrise value: \(type(of: sunriseValue))")
let sunriseDate = Date(timeIntervalSince1970: sunriseValue as! TimeInterval)
print("Sunrise date: \(sunriseDate)")
let sunrise = formatter.string(from: sunriseDate)
print("Sunrise: \(sunrise)")
// Finally, determine sunset date and sunset time
let sunsetValue = sys["sunset"]
let sunsetDate = Date(timeIntervalSince1970: sunsetValue as! TimeInterval)
let sunset = formatter.string(from: sunsetDate)
print("Sunset: \(sunset)")
print("-----------------")
} catch {
print("Open Weather JSON Processing failed.")
}
} else {
print("There was an error inside openWeatherTask: ", error!)
}
}
openWeatherTask.resume()
// MARK: - NASA LARC API
guard let urlJSONNASA = URL(string: "https://power.larc.nasa.gov/cgi-bin/v1/DataAccess.py?request=execute&identifier=SinglePoint¶meters=DNR,DIFF,ALLSKY_SFC_SW_DWN&userCommunity=SSE&tempAverage=CLIMATOLOGY&outputList=JSON&lat=51.994693&lon=4.378553&user=anonymous") else {
print("Could not retrieve the URL of NASA")
return
}
print("NASA URL API: \(urlJSONNASA)")
let nasaTask = URLSession.shared.dataTask(with: urlJSONNASA) { (data, response, error) in
if error == nil {
guard let urlNASAContent = data else{ return }
do{
let nasaJSONResult = try JSONSerialization.jsonObject(with: urlNASAContent, options: JSONSerialization.ReadingOptions.mutableContainers) as! [String:Any]
print("-----------------")
guard let features = nasaJSONResult["features"] as? Array<[String:Any]> else {
print("Error retrieving 'features'.")
return
}
print("This is the 'features' array:", features)
print("-----------------")
guard let singleFeature = features.first else{
print("Error retrieving 'singleFeature'.")
return
}
guard let geometry = singleFeature["geometry"] as? [String:Any] else {
print("Error retrieving 'geometry'.")
return
}
print("Geometry: ", geometry)
let coordinates = geometry["coordinates"] as? Array<Double>
print("Coordinates: ", coordinates!)
let nasaLat = coordinates?[1]
let nasaLon = coordinates?[0]
print("NASA Latitude: \(String(describing: nasaLat!))º | NASA Longitude: \(String(describing: nasaLon!))º")
print("---------------------")
guard let properties = singleFeature["properties"] as? [String:Any] else{
print("Error retrieving 'properties'.")
return
}
let parameter = properties["parameter"] as? [String:Any]
print("Parameters: ", parameter!)
let ghi_raw = parameter!["ALLSKY_SFC_SW_DWN"] as? [String:Double]
print("GHI raw: ", ghi_raw!)
let dhi_raw = parameter!["DIFF"] as? [String:Double]
print("DHI raw: ", dhi_raw!)
let dni_raw = parameter!["DNR"] as? [String:Double]
print("DNI raw: ", dni_raw!)
print("---------------------")
// Put an order on each irradiance
for index in 1...12{
self.DNI[index - 1] = (dni_raw?[String(index)])!
self.DHI[index - 1] = (dhi_raw?[String(index)])!
self.GHI[index - 1] = (ghi_raw?[String(index)])!
}
print("DNI ordered: ", self.DNI)
print("DHI ordered: ", self.DHI)
print("GHI ordered: ", self.GHI)
print("---------------------")
guard let parameterInformation = nasaJSONResult["parameterInformation"] as? [String:Any] else {
print("Error retrieving 'parameterInformation'.")
return
}
print("ParameterInformation: ", parameterInformation)
print("---------------------")
guard let ghi_paramInfo = parameterInformation["ALLSKY_SFC_SW_DWN"] as? [String:Any] else {
print("Error retriving the GHI inside the parameter information.")
return
}
print("GHI in parameter information: ", ghi_paramInfo)
print("Long name of GHI in parameter information: ", ghi_paramInfo["longname"]!)
print("Units of GHI in parameter information: ", ghi_paramInfo["units"]!)
print("---------------------")
guard let dhi_paramInfo = parameterInformation["DIFF"] as? [String:Any] else {
print("Error retrieving the DHI inside the parameter information.")
return
}
print("DHI in parameter information: ", dhi_paramInfo)
print("Long name of GHI in parameter information: ", dhi_paramInfo["longname"]!)
print("Units of GHI in parameter information: ", dhi_paramInfo["units"]!)
print("---------------------")
guard let dni_paramInfo = parameterInformation["DNR"] as? [String:Any] else{
print("Error retrieving the DHI inside the parameter information.")
return
}
print("DNI in parameter information: ", dni_paramInfo)
print("Long name of DNI in parameter information: ", dni_paramInfo["longname"]!)
print("Units of DNI in parameter information: ", dni_paramInfo["units"]!)
print("---------------------")
} catch {
print("NASA JSON processing failed.")
}
} else {
print("There was an error inside the nasaTask: ", error!)
}
}
nasaTask.resume()
}
}
可编码方法:
//MARK: - Structs to get the information from the openWeather API
struct OWElements:Codable {
var coord:CoordinatesDetails
var weather:[WeatherDetails]
var main:MainDetails
var wind:WindDetails
var sys:SysDetails
var name:String
}
struct CoordinatesDetails:Codable {
var lon:Float
var lat:Float
}
struct WeatherDetails:Codable {
var id:Int
var main:String
var description:String
var icon:String
}
struct MainDetails:Codable {
var temp:Float
var pressure:Float
var humidity:Float
var temp_min:Float
var temp_max:Float
}
struct WindDetails:Codable {
var speed:Float
var deg:Int
}
struct SysDetails:Codable {
var type:Int
var id:Int
var message:Float
var country:String
var sunrise:Int
var sunset:Int
}
//MARK: - Structs to get the information from the NASA API
struct NASAElements:Codable {
var features:[FeaturesDetails]
var parameterInformation:ParameterInformationDetails
}
struct FeaturesDetails:Codable {
var geometry:GeometryDetails
var properties:PropertiesDetails
}
struct GeometryDetails:Codable {
var coordinates:[Double]
}
struct PropertiesDetails:Codable {
var parameter:ParameterDetails
}
struct ParameterDetails:Codable {
var ALLSKY_SFC_SW_DWN:[String:Double]
var DIFF:[String:Double]
var DNR:[String:Double]
}
struct ParameterInformationDetails:Codable {
var ALLSKY_SFC_SW_DWN:ALLSKY_SFC_SW_DWNDetails
var DIFF:DIFFDetails
var DNR:DNRDetails
}
struct ALLSKY_SFC_SW_DWNDetails:Codable {
var longname:String
var units:String
}
struct DIFFDetails:Codable {
var longname:String
var units:String
}
struct DNRDetails:Codable {
var longname:String
var units:String
}
// MARK: - Class ViewController
class ViewController: UIViewController {
// MARK: - Variables and constants
var DNI = [Double](repeating: 0.0, count: 12)
var DHI = [Double](repeating: 0.0, count: 12)
var GHI = [Double](repeating: 0.0, count: 12)
// MARK: - Method viewDidLoad()
override func viewDidLoad() {
super.viewDidLoad()
// MARK: Open Weather API
guard let urlJSONOpenWeather = URL(string: "http://api.openweathermap.org/data/2.5/weather?lat=51.9946&lon=4.378799&appid=get_api_id_openweather") else {
print("There was an error on retrieving the Open Weather JSON url.")
return
}
let openWeatherTask = URLSession.shared.dataTask(with: urlJSONOpenWeather) { (data, response, error) in
if error == nil{
guard let urlOpenWeatherData = data else{
print("Error in the guard let urlOpenWeatherData")
return
}
do {
let openWeatherElements = try JSONDecoder().decode(OWElements.self, from: urlOpenWeatherData)
print("This is the openWeather Elements:\n \(openWeatherElements)")
// MARK: - Getting the coordinates (latitude and longitude)
let openWeatherLatitude = openWeatherElements.coord.lat
let openWeatherLongitude = openWeatherElements.coord.lon
print("OpenWeather Latitude:\n \(openWeatherLatitude)º")
print("OpenWeather Longitude:\n \(openWeatherLongitude)º")
print("-----------------")
// MARK: - Getting the weather description from an array of dictionary.
let openWeatherWeatherArray = openWeatherElements.weather
print("OpenWeather Weather Array:\n \(openWeatherWeatherArray)")
guard let weather = openWeatherWeatherArray.first else {
print("There was an error on retrieving the elements of the 'weather' array.)")
return
}
print("These are the weatherArray elements: ", weather)
print("ID: \(weather.id)")
print("Main: \(weather.main)")
print("Description: \(weather.description)")
print("Icon: \(weather.icon)")
print("-----------------")
// MARK: - Getting the "main" elements
let main = openWeatherElements.main
print("This is main:\n \(main)")
print("Temperature in Kelvin: \(main.temp)K")
print("Pressure: \(main.pressure) hPa")
print("Humidity: \(main.humidity)")
let tempInCelsius = main.temp - 273.15
print("Temperature in Celsius: \(String(format:"%.2f", tempInCelsius))ºC")
let maxTempCelsius = main.temp_max - 273.15
print("Max temperature in Kelvin: \(main.temp_max)K")
print("Max temperature in Celsius: \(String(format:"%.2f", maxTempCelsius))ºC")
let minTempCelsius = main.temp_min - 273.15
print("Min temperature in Kelvin: \(main.temp_min)K")
print("Min temperature in Celsius: \(String(format:"%.2f", minTempCelsius))ºC")
print("-----------------")
let windDetails = openWeatherElements.wind
print("Wind speed: \(windDetails.speed)m/s")
print("Wind direction: \(windDetails.deg)º")
print("-----------------")
let sysDetails = openWeatherElements.sys
print("Type: \(sysDetails.type)")
print("ID: \(sysDetails.id)")
print("Message: \(sysDetails.message)")
print("Country: \(sysDetails.country)")
print("Sunrise: \(sysDetails.sunrise)")
print("Sunset: \(sysDetails.sunset)")
// First, we create a format of time for the sunrise and sunset
let formatter = DateFormatter()
formatter.dateStyle = .none
formatter.dateStyle = .medium
formatter.dateFormat = "HH:mm:ss"
// Second, determine sunrise date and get sunrise time
let sunriseValue = sysDetails.sunrise
print("Sunrise Value: \(sunriseValue)")
let sunriseDate = Date(timeIntervalSince1970: Double(sunriseValue))
print("Sunrise date: \(sunriseDate)")
let sunsetValue = sysDetails.sunset
let sunsetDate = Date(timeIntervalSince1970: Double(sunsetValue))
print("Sunset date: \(sunsetDate)")
// Finally, determine sunset date and sunset time
let sunrise = formatter.string(from: sunriseDate)
let sunset = formatter.string(from: sunsetDate)
print("Sunrise: \(sunrise)")
print("Sunset: \(sunset)")
print("-----------------")
print("Region: \(openWeatherElements.name)")
print("-----------------")
}catch{
print("Open Weather JSON Processing failed: \(error.localizedDescription)")
}
}
}
openWeatherTask.resume()
//MARK: - NASA API
guard let urlJSONNASA = URL(string: "https://power.larc.nasa.gov/cgi-bin/v1/DataAccess.py?request=execute&identifier=SinglePoint¶meters=DNR,DIFF,ALLSKY_SFC_SW_DWN&userCommunity=SSE&tempAverage=CLIMATOLOGY&outputList=JSON&lat=51.994693&lon=4.378553&user=anonymous") else{
print("Could not retrieve the URL of NASA")
return
}
let nasaTask = URLSession.shared.dataTask(with: urlJSONNASA) { (data, response, error) in
if error == nil {
guard let nasaData = data else{
print("Error in the guard let nasaData")
return
}
do{
let nasaElements = try JSONDecoder().decode(NASAElements.self, from: nasaData)
print("These are the NASA elements:\n \(nasaElements)")
print("-----------------")
let featuresArray = nasaElements.features
print("Features as Array:\n \(featuresArray)")
guard let features = featuresArray.first else{
print("There was an error on retrieving the elements of the 'features' array in the NASA API.)")
return
}
print("Features: \(features)")
let geometry = features.geometry
print("Geometry: \(geometry)")
let NASALatitude = geometry.coordinates[1]
let NASALongitude = geometry.coordinates[0]
print("NASA Latitude: \(NASALatitude)º")
print("NASA Longitude: \(NASALongitude)º")
print("-----------------")
let properties = features.properties
print("Properties:\n \(properties)")
print("-----------------")
let parameter = properties.parameter
print("Parameters:\n \(parameter)")
print("-----------------")
let ghi_raw = parameter.ALLSKY_SFC_SW_DWN
let dni_raw = parameter.DNR
let dhi_raw = parameter.DIFF
print("GHI raw: \(dni_raw)")
print("DNI raw: \(dni_raw)")
print("DHI raw: \(dhi_raw)")
// Put an order on each irradiance
for index in 1...12{
self.DNI[index - 1] = (dni_raw[String(index)])!
self.DHI[index - 1] = (dhi_raw[String(index)])!
self.GHI[index - 1] = (ghi_raw[String(index)])!
}
print("GHI ordered: ", self.GHI)
print("DNI ordered: ", self.DNI)
print("DHI ordered: ", self.DHI)
print("---------------------")
let parameterInformation = nasaElements.parameterInformation
print("Parameter Information:\n \(parameterInformation)")
let ghiInfo = parameterInformation.ALLSKY_SFC_SW_DWN
let dniInfo = parameterInformation.DNR
let dhiInfo = parameterInformation.DIFF
print("GHI Info: \(ghiInfo)")
print("DNI Info: \(dniInfo)")
print("DHI Info: \(dhiInfo)\n")
print("GHI name: \(ghiInfo.longname)")
print("GHI units: \(ghiInfo.units)\n")
print("DNI name: \(dniInfo.longname)")
print("DNI units: \(dniInfo.units)\n")
print("DHI name: \(dhiInfo.longname)")
print("DHI units: \(dhiInfo.units)\n")
print("---------------------")
} catch {
print("NASA JSON Processing failed: \(error.localizedDescription)")
}
}
}
nasaTask.resume()
}
}
我希望这对将来的某人可能有所帮助.问候.
I hope this may be helpful for someone in the future. Greets.
这篇关于如何在Swift 4-5中使用Structs和Decodable从API中提取信息?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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