Live Data in Practice

In this tutorial you will learn to work with Live Data / Real Time Data in MapsIndoors. It is recommended that you read the Live Data Introduction before continueing. It is also recommended that you read Getting Started to see how to setup a MapView and initialize MapsIndoors. To make this example work, you need a valid MapsPeople API key that allows access to live data. Also, don't forget to enable your accessible live data in the domainType variable in the toggleLiveData() function e.g.

1. MPLiveDomainType.availability

2. MPLiveDomainType.occupancy

3. MPLiveDomainType.co2

4. MPLiveDomainType.temperature

5. MPLiveDomainType.humidity

6. MPLiveDomainType.count

7. MPLiveDomainType.position

In this example we will use the occupancy and position live data.

Firstly, create a class LiveDataController that inherits from UIViewController.

class LiveDataController: UIViewController {

} 

Add buttons for toggling subscriptions, one button for Live Position Updates and one for Live Occupancy Updates.

let positionButton = UIButton.init()
let occupancyButton = UIButton.init()

Add a method setupLiveDataButtons() setting up buttons that enables/disables the subscriptions.

fileprivate func setupLiveDataButtons() {
    positionButton.setTitle("See Live Positions", for: .normal)
    positionButton.setTitle("Tracking Live Positions", for: .selected)
    positionButton.addTarget(self, action: #selector(togglePosition), for: .touchUpInside)
    positionButton.backgroundColor = UIColor.blue

    occupancyButton.setTitle("See Live Occupancy", for: .normal)
    occupancyButton.setTitle("Showing Live Occupancy", for: .selected)
    occupancyButton.addTarget(self, action: #selector(toggleOccupancy), for: .touchUpInside)
    occupancyButton.backgroundColor = UIColor.red
}

Add a method toggleLiveData() that does the actual toggling of Live Data for a button based on the buttons isSelected flag. Swap current selected state for button. If the flag is true and the button is selected, call the MPMapControl.enableLiveData() method with the given Domain Type. We will also call a startFlash()method that should make the button flash. More on this later. If the flag is false and the button is not selected, call the MPMapControl.disableLiveData() method with the given Domain Type. Similarly we will call a stopFlash()method that should stop the button flash. In this example, we choose to have a customized rendering of Live Data, so we provide a Handler instance that gets the updated Locations. We will get to that later.

fileprivate func toggleLiveData(_ button: UIButton, _ domainType: String) {
    button.isSelected = !button.isSelected
    if button.isSelected {
        mapControl?.enableLiveData(domain: domainType, listener: nil)
        button.startFlash()
    } else {
        mapControl?.disableLiveData(domain: domainType)
        button.stopFlash()
    }
}

Define an Objective-C method togglePosition() that will receive events from your positionButton. In this method create a position Topic Criteria and call togglePosition with the button and the Topic Criteria.

@objc func togglePosition(button:UIButton) {
    toggleLiveData(button, MPLiveDomainType.position)
}

Define an Objective-C method toggleOccupancy() that will receive events from your occupancyButton. In this method create a occupancy Topic Criteria and call togglePosition with the button and the Topic Criteria.

@objc func toggleOccupancy(button:UIButton) {
    toggleLiveData(button, MPLiveDomainType.occupancy)
}

Inside viewDidLoad(), also request a building and go to this building on the map.

 Task {
        let locations = await MPMapsIndoors.shared.locationsWith(query: nil, filter: nil)
        if let loc = locations.first {
            mapControl?.goTo(entity: loc)
        }
    }

As an example, you can set up your buttons in your viewDidLoad() method. You can also set if up elsaware if thats your wish.

Inside viewDidLoad() method, call setupLiveDataButtons() arrange the map view and the buttons in stackviews.

setupLiveDataButtons()
let buttonStackView = UIStackView.init(arrangedSubviews: [positionButton, occupancyButton])
buttonStackView.axis = .horizontal
buttonStackView.distribution = .fillEqually
let stackView = UIStackView.init(arrangedSubviews: [map!, buttonStackView])
stackView.axis = .vertical
view = stackView

Optionally, when you leave this controller, unsubscribe all Live Update Topics.

override func viewDidDisappear(_ animated: Bool) {
    mapControl?.disableLiveData(MPLiveDomainType.position)
    mapControl?.disableLiveData(MPLiveDomainType.occupancy)
}

Earlier we called some non-existing methods, startFlash() and stopFlash() on a UIButton. We will create these methods now. Create an extension for UIButton and add the methods startFlash() and stopFlash() that creates and adds an animation layer that manipulates with the opacity of the button over time.

extension UIButton {
    func startFlash() {
        let flash = CABasicAnimation(keyPath: "opacity")
        flash.duration = 0.5
        flash.fromValue = 1
        flash.toValue = 0.5
        flash.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseInEaseOut)
        flash.autoreverses = true
        flash.repeatCount = .greatestFiniteMagnitude
        layer.add(flash, forKey: "flash")
    }
    func stopFlash() {
        layer.removeAnimation(forKey: "flash")
    }
}

Expected Result​