iOS Dev. Lesson 6
Agenda
- Finish weather data fetching
- Expanding weather app with Tab Bar Controller
- Understanding and using Tab Bar Controller
- Combining Tab Bar with Navigation Controller
- Tab Bar x Navigation x Table View Controller
Weather Data Fetching So Far
Step 1: Creating the user interface
Step 2: Connect the IBOutlets
@IBOutlet weak var weatherIcon: UIImageView!
@IBOutlet weak var temperatureLabel: UILabel!
@IBOutlet weak var windLabel: UILabel!
@IBOutlet weak var dateLabel: UILabel!
@IBOutlet weak var todayLabel: UILabel!Step 3: Inspect the JSON structure
Step 4: Defining the Weather Decodable struct
struct Weather: Decodable {
var date = ""
var temperature = ""
var humidity = ""
var windSpeed = ""
var today = ""
var statusCode = ""
}Step 5: Defining the fetchWeather function
func fetchWeather() {
guard let url = URL(string: "https://dev.makzan.net/weather.json") else {
return
}
URLSession.shared.dataTask(with: url) { (data, response, error) in
if error != nil {
print("Fetch Error:")
print(error!)
return
}
guard let data = data, let response = response else {
return
}
print(response)
do {
let json = try JSONDecoder().decode(Weather.self, from: data)
// Store the data
self.weather = json
// Let’s check the weather
print(self.weather)
// Update the UI view
DispatchQueue.main.async {
self.updateView()
}
} catch let error {
print("JSON Decode Error:")
print(error)
}
}.resume()
}Step 6: Defining the updateView function
func updateView() {
temperatureLabel.text = "\(weather.temperature)℃"
windLabel.text = weather.windSpeed + "km/hr"
dateLabel.text = weather.date
todayLabel.text = weather.today
// Update weather icon based on status code
// Reference: https://xml.smg.gov.mo/#Status
switch weather.statusCode {
case "01":
weatherIcon.image = UIImage(systemName: "sun.max.fill")
case "02", "03":
weatherIcon.image = UIImage(systemName: "cloud.fill")
case "12":
weatherIcon.image = UIImage(systemName: "cloud.rain.fill")
case "13":
weatherIcon.image = UIImage(systemName: "cloud.heavyrain.fill")
default:
weatherIcon.image = UIImage(systemName: "sun.min.fill")
}
}Full Code
The ViewController.swift
we have so far:
- IBOutlets defined
- Weather structure defined
- fetchWeather function
- updateView function
class ViewController: UIViewController {
@IBOutlet weak var weatherIcon: UIImageView!
@IBOutlet weak var temperatureLabel: UILabel!
@IBOutlet weak var windLabel: UILabel!
@IBOutlet weak var dateLabel: UILabel!
@IBOutlet weak var todayLabel: UILabel!
var weather = Weather()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
fetchWeather()
}
func updateView() {
temperatureLabel.text = "\(weather.temperature)℃"
windLabel.text = weather.windSpeed + "km/hr"
dateLabel.text = weather.date
todayLabel.text = weather.today
// Update weather icon based on status code
// Reference: https://xml.smg.gov.mo/#Status
switch weather.statusCode {
case "01":
weatherIcon.image = UIImage(systemName: "sun.max.fill")
case "02", "03":
weatherIcon.image = UIImage(systemName: "cloud.fill")
case "12":
weatherIcon.image = UIImage(systemName: "cloud.rain.fill")
case "13":
weatherIcon.image = UIImage(systemName: "cloud.heavyrain.fill")
default:
weatherIcon.image = UIImage(systemName: "sun.min.fill")
}
}
func fetchWeather() {
guard let url = URL(string: "https://dev.makzan.net/weather.json") else {
return
}
URLSession.shared.dataTask(with: url) { (data, response, error) in
if error != nil {
print("Fetch Error:")
print(error!)
return
}
guard let data = data, let response = response else {
return
}
print(response)
do {
let json = try JSONDecoder().decode(Weather.self, from: data)
// Store the data
self.weather = json
// Let’s check the weather
print(self.weather)
// Update the UI view
DispatchQueue.main.async {
self.updateView()
}
} catch let error {
print("JSON Decode Error:")
print(error)
}
}.resume()
}
}
// Weather struct, we need date, temperature, humidity, windSpeed, today, statusCode
struct Weather: Decodable {
var date = ""
var temperature = ""
var humidity = ""
var windSpeed = ""
var today = ""
var statusCode = ""
}Video Demo
Tab Bar Controller
Tab Bar Controller Basic
iOS Dev. Lesson 6
By makzan
