iOS Dev. Lesson 10

Agenda

Put all weather data fetching into Weather.swift
Showing cities in Map View
Showing external website with SFSafariController

Weather.swift

struct WeatherService {
    // 3 functions here    
}

struct WeatherService {
    public func fetchCurrentWeather( completion: ((Weather) -> Void)? = nil) {
        guard let url = URL(string: "https://dev.makzan.net/weather.json") else { return }

        URLSession.shared.dataTask(with: url) { (data, response, error) in
            guard let data = data else { return }
            
            if error != nil {
                print(error!)
                return
            }
            
            do {
                let json = try JSONDecoder().decode(Weather.self, from: data)
                
                completion?(json)
                
            } catch let error{
                print("Fetch error.")
                print(error)
            }
        }.resume()
    }
    
    // 2 more functions here    
}

What is

completion function parameter?

struct WeatherService {
    public func fetchCurrentWeather( completion: ((Weather) -> Void)? = nil) {
        //...
                
		completion?(json)
        
        //...
    }
    
    // 2 more functions here    
}

public func hello( completion: ((String)->Void)?=nil) {
	completion?("Result Here")
}

struct WeatherService {
    public func fetchCurrentWeather( completion: ((Weather) -> Void)? = nil) {
        guard let url = URL(string: "https://dev.makzan.net/weather.json") else { return }

        URLSession.shared.dataTask(with: url) { (data, response, error) in
            guard let data = data else { return }
            
            if error != nil {
                print(error!)
                return
            }
            
            do {
                let json = try JSONDecoder().decode(Weather.self, from: data)
                
                completion?(json)
                
            } catch let error{
                print("Fetch error.")
                print(error)
            }
        }.resume()
    }
    
    public func fetchForecastWeather( completion: (([ForecastDay]) -> Void)? = nil) {
        guard let url = URL(string: "https://dev.makzan.net/weather.json") else { return }

        URLSession.shared.dataTask(with: url) { (data, response, error) in
            guard let data = data else { return }
            
            if error != nil {
                print(error!)
                return
            }
            
            do {
                let json = try JSONDecoder().decode(Forecast.self, from: data)
                
                completion?(json.forecasts)
                
            } catch let error{
                print("Fetch error.")
                print(error)
            }
        }.resume()
    }
    
    // 1 more function here    
}

struct WeatherService {
    public func fetchCurrentWeather( completion: ((Weather) -> Void)? = nil) {
        guard let url = URL(string: "https://dev.makzan.net/weather.json") else { return }

        URLSession.shared.dataTask(with: url) { (data, response, error) in
            guard let data = data else { return }
            
            if error != nil {
                print(error!)
                return
            }
            
            do {
                let json = try JSONDecoder().decode(Weather.self, from: data)
                
                completion?(json)
                
            } catch let error{
                print("Fetch error.")
                print(error)
            }
        }.resume()
    }
    
    public func fetchForecastWeather( completion: (([ForecastDay]) -> Void)? = nil) {
        guard let url = URL(string: "https://dev.makzan.net/weather.json") else { return }

        URLSession.shared.dataTask(with: url) { (data, response, error) in
            guard let data = data else { return }
            
            if error != nil {
                print(error!)
                return
            }
            
            do {
                let json = try JSONDecoder().decode(Forecast.self, from: data)
                
                completion?(json.forecasts)
                
            } catch let error{
                print("Fetch error.")
                print(error)
            }
        }.resume()
    }
    
    public func fetchCitiesWeather( completion: (([CityWeather]) -> Void)? = nil) {
        guard let url = URL(string: "https://dev.makzan.net/cities_weather.json") else { return }

        URLSession.shared.dataTask(with: url) { (data, response, error) in
            guard let data = data else { return }
            
            if error != nil {
                print(error!)
                return
            }
            
            do {
                let json = try JSONDecoder().decode(CitiesWeather.self, from: data)
                
                completion?(json.cities)
                
            } catch let error{
                print("Fetch error.")
                print(error)
            }
        }.resume()
    }
    
    // 1 more function here    
}

struct Weather:Decodable {
    var date: String = ""
    var temperature: String = ""
    var humidity: String = ""
    var windSpeed: String = ""
    var windDescription: String = ""
    var today:String = ""
    var statusCode:String = ""
    var todayDescription = ""
    var tomorrowDescription = ""
}

struct Forecast:Decodable {
    var forecasts: [ForecastDay] = []
}

struct ForecastDay:Decodable {
    var date:String = ""
    var statusCode:String = ""
    var temperatureLow:String = ""
    var temperatureHigh:String = ""
    var description:String = ""
}

struct CitiesWeather:Decodable {
    var cities: [CityWeather] = []
}
struct Coordinate:Decodable {
    var latitude: Double
    var longitude: Double
}
struct CityWeather:Decodable {
    var cityName:String = ""
    var date:String = ""
    var temperatureLow:String = ""
    var temperatureHigh:String = ""
    var description:String = ""
    var coordinate:Coordinate
}

struct StatusCode {

    // https://xml.smg.gov.mo/#Status
    static let statusCodes = [
        "01": "sun.max.fill",
        "a1": "moon.fill",
        "02": "cloud.sun.fill",
        "a2": "cloud.moon.fill",
        "03": "cloud.fill",
        "04": "cloud.fill",
        "12": "cloud.rain.fill",
        "13": "cloud.rain.fill",
        "16": "cloud.heavyrain.fill",
        "17": "cloud.heavyrain.fill",
        "18": "cloud.bolt.rain.fill",
        "25": "cloud.bolt.fill",
        "27": "cloud.rain.fill",
        "28": "cloud.rain.fill",
        "c8": "cloud.moon.rain.fill",
        "29": "cloud.rain.fill",
        "c9": "cloud.moon.rain.fill",
    ]

    static func symbolFor(statusCode:String) -> String {
        return statusCodes[statusCode] ?? "sun.fill"
    }
}

Map View

CitiesMapViewController

import MapKit

import UIKit
import MapKit

class CitiesMapViewController: UIViewController {

    @IBOutlet weak var mapView: MKMapView!
    
    var cities: [CityWeather] = []
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
        
        
        let coordinate = CLLocationCoordinate2D(latitude: 32.59037534587093, longitude: 114.95212987586083)
        
        // 5,000KM x 3,000KM
        let region = MKCoordinateRegion(center: coordinate, latitudinalMeters: 5000*1000, longitudinalMeters: 3000*1000)
        
        mapView.setRegion(region, animated: false)
        
        // fetch cities weather
        WeatherService().fetchCitiesWeather { (cities) in
            self.cities = cities
            DispatchQueue.main.async {
                self.renderCities()
            }
            
        }
    }

    func renderCities() {
        var annotations: [MKAnnotation] = []
        for city in cities {
            let annotation = MKPointAnnotation()
            annotation.coordinate = CLLocationCoordinate2D(latitude: city.coordinate.latitude, longitude: city.coordinate.longitude)
            annotation.title = city.cityName
            annotation.subtitle = "\(city.temperatureLow)—\(city.temperatureHigh) \(city.description)"
            annotations.append(annotation)
        }
        mapView.addAnnotations(annotations)
    }

}

SFSafariController

import SafariServices

@IBAction func tapDetails(_ sender: Any) {
    guard let url = URL(string: "https://www.smg.gov.mo/") else {
      return
    }
    let vc = SFSafariViewController(url: url)
    self.show(vc, sender: false)
}

deck

By makzan

iOS Dev. Lesson 10

iOS Dev. Lesson 10

Weather.swift

What is

completion function parameter?

Map View

CitiesMapViewController

SFSafariController

deck

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