Brew MVVM

brewMVVM.swift

class Brew {
    var temp: Float = 0.0
}

class BrewViewModel : NSObject {
    var brew = Brew()
    dynamic var temp: Float = 0.0 {
        didSet {
            self.brew.temp = temp
        }
    }
    
    override init() {
        super.init()
        self.connectToHost()
    }
    
    func connectToHost() {
        SIOSocket.socketWithHost("http://brewcore-demo.herokuapp.com", response: {socket in
            socket.on("temperature_changed", callback: {(AnyObject data) -> Void in
                self.temp = data[0] as Float
            })
        })
    }

}

class BrewViewController: UIViewController {
    @IBOutlet weak var tempLabel: UILabel!
    let brewViewModel = BrewViewModel()

    private var brewContext = 0
    
    required init(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        self.brewViewModel.addObserver(self, forKeyPath: "temp", options: .New, context: &brewContext)
    }

  override func observeValueForKeyPath(keyPath: String, ofObject object: AnyObject, change: [NSObject : AnyObject], context: UnsafeMutablePointer<Void>) {
        if context == &brewContext {
            dispatch_async(dispatch_get_main_queue(), {
                self.updateTempLabel((change[NSKeyValueChangeNewKey]) as Float)               
            })
        } else {
            super.observeValueForKeyPath(keyPath, ofObject: object, change: change, context: context)
        }
    }
    
    func updateTempLabel(temp: Float) {
       self.tempLabel.text = NSString(format:"%.2f ˚C", temp)
    }
    
}