UIDevice Extension to Determine Device

Autolayout is excellent for dynamically sizing your user-interface when developing for iOS or tvOS, but sometimes you need to know the specific device you're building for.

The following UIDevice extension allows you to do exactly that. The values for each iPhone type indicate the screen size in inches. For instance, .iPhone55 refers to an iPhone 6 Plus / 6S Plus.

Place this code in a file such as UIDeviceExtension.swift, or something similar.

import UIKit

extension UIDevice {  
    enum DeviceType {
        case iPhone35
        case iPhone40
        case iPhone47
        case iPhone55
        case iPad
        case TV

        var isPhone: Bool {
            return [ .iPhone35, .iPhone40, .iPhone47, .iPhone55 ].contains(self)
        }
    }

    var deviceType: DeviceType? {
        switch UIDevice.currentDevice().userInterfaceIdiom {
        case .TV:
            return .TV

        case .Pad:
            return .iPad

        case .Phone:
            let screenSize = UIScreen.mainScreen().bounds.size
            let height = max(screenSize.width, screenSize.height)

            switch height {
            case 480:
                return .iPhone35
            case 568:
                return .iPhone40
            case 667:
                return .iPhone47
            case 736:
                return .iPhone55
            default:
                return nil
            }

        case .Unspecified:
            return nil
        }
    }
}

You can use this code as follows:

guard let type = UIDevice.currentDevice().deviceType  
else {  
    // Unknown type
    return
}

if type == .TV {  
    // Code specific to Apple TV
}
else if type == .iPhone47 {  
    // Code specific to iPhone 6/6S
}
else if type.isPhone {  
    // Code specific to other iPhones
}