How to determine if user is in lightning or classic

Salesforce has properties called UITheme and UIThemeDisplayed in the $User global variable for use in visual force pages. When I access skuid’s version of the $User global variable, I don’t see these properties. How can I know if a user is in lightning or classic from a skuid page?

In version 10 of Skuid, from JavaScript you can do the following check to determine whether you’re in Lightning Experience:

var inLEX = skuid.platform.get("SFUITheme")==="Theme4d";console.log("Are we in Lightning Experience? " + (inLEX ? "Yes" : "No"));