Is there a correct/recommended way of detecting my UWP app I'm running on a Phone?

Question

Trying out Windows Universal apps with JavaScript I noticed the WinJS.Utilities.isPhone property is no longer available, which makes sense since there would be no reason to ask for that at runtime.

I do want to know just for testing purposes if there is a proper way of detecting the device my app is running in.

EDIT: My question is NOT about detecting a mobile browser. I'm talking about about a brand new Universal Windows App for Window 10 that can run on phones, desktops, tablets, Xbox, HoloLEns, IoT devices et all. WinJS had a property that would tell me whether I was running on the phone or not. That property is now gone. Please don't close this question due to duplicate with "detecting mobile browser". That is NOT what I need.

Answer 1

Caveat: Any form of device detection is fragile due to the dynamic nature of hardware - a new device could come along tomorrow that breaks your app's logic. It is best to use these APIs only for telemetry / analytics rather than to trigger runtime behaviour.

More often than not, what you really want to know is some attribute of the device or the app that is not inherently tied to the device family (does this device support SystemTray API? Is there a keyboard attached? Is the window more than 500px wide? etc.).

That said, in Windows 10 you can query the DeviceFamily via AnalyticsInfo.VersionInfo.DeviceFamily and it will tell you things like "Mobile" or "Desktop" or "Xbox" etc. (where "Mobile" could be any class of device - phone, tablet, etc.). There is also a property DeviceForm that might be helpful, but again you can't really rely on it at runtime to deterministically say you're running on "a phone."

So basically the answer is "you can use these APIs for telemetry but don't hard-code any values into your app lest it break when a new device arrives on the market." At the very least, always make sure you handle the case where the returned value isn't one you know about a-priori.