Identify user web browser information on Shiny Server

Question

In Shiny Server, I can get client information using session$clientData . In my current project I use

 parseQueryString(session$clientData$url_search) 

Get parameters in URL. I also want to get information about the web browser (information that Google collects for analytics). Although I could probably figure out how to do this in ASP.NET or PHP, possibly JS, I don’t quite understand how to interweave in my own JS in a Shiny application and pass the received information to a variable.

How can I get browser information sent with a request to a web page?