Changing the view color when comparing values - swift

Question

I created a view to use as background and I would like to change its color when label text is greater or less than variable number. The script is okay but the color is not changing.
Thanks in advance.
import UIKit
class ViewController: UIViewController, UITextFieldDelegate {
#IBOutlet weak var localName: UITextField!
#IBOutlet weak var localNameLabel: UILabel!
#IBOutlet weak var localTemp: UILabel!
#IBAction func getData(sender: AnyObject) {
getWeatherData("http://api.openweathermap.org/data/2.5/weather?q=" + localName.text! + "")
}
#IBOutlet weak var fundo: UIView!
override func viewDidLoad() {
super.viewDidLoad()
getWeatherData("http://api.openweathermap.org/data/2.5/weather?q=London")
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func getWeatherData(urlString: String){
let url = NSURL (string: urlString)
let task = NSURLSession.sharedSession().dataTaskWithURL(url!) { (data, response, error) in
dispatch_async(dispatch_get_main_queue(), {
self.setLabels(data!)
})
}
task.resume()
}
func setLabels(weatherData: NSData) {
do {
let json = try NSJSONSerialization.JSONObjectWithData(weatherData, options:NSJSONReadingOptions.MutableContainers) as! NSDictionary
print(json)
//localNameLabel.text = json[("name")] as? String
if let name = json[("name")] as? String {
localNameLabel.text = name
}
if let main = json[("main")] as? NSDictionary {
if let temp = main[("temp")] as? Double {
//convert kelvin to celsius
let ft = (temp - 273.15)
let myString = ft.description
localTemp.text = myString
self.changeColor()
}
}
} catch let error as NSError {
print(error)
}
var number : Float
func changeColor(){
number = 19.0
if(Float(localTemp.text!) < number){
fundo.backgroundColor = .blueColor()
}else{
fundo.backgroundColor = .orangeColor()
}
}
}
}
Edited to post the entire script

Answer 1

In your view controller you need to add UITextFieldDelegate which will allow you to access methods related to your text field. The top of your view controller should look like this:
class ViewController: UIViewController,UITextFieldDelegate //set delegate to class
You then need to set the delegate of your text field to self in viewDidLoad and add a target for when the text field changes:
override func viewDidLoad() {
super.viewDidLoad()
localTemp.delegate = self //set delegate to this vc
localTemp.addTarget(self, action: "textFieldDidChange:", forControlEvents: UIControlEvents.EditingChanged)
}
You can then implement this method which will run on every key press and you need to call your changeColor() method as above:
func textFieldDidChange(textField: UITextField) {
self.changeColor()
}