I'm developing a web application that uses PhoneGap:Build for a mobile version and want to have a single codebase for the 'desktop' and mobile versions. I want to be able to detect if PhoneGap calls will work (ie, is the user on a mobile device that will support PhoneGap).

I've searched and cannot believe there is no simple way of doing this. Many people have offered suggestions;

• http://www.sencha.com/forum/showthread.php?144127-Checking-if-running-in-PhoneGap-or-Mobile-Web-Browser
• http://groups.google.com/group/phonegap/browse_thread/thread/322e80bd41bb1a54/a421300eb2a2029f?lnk=gst&q=detect+desktop#a421300eb2a2029f
• http://groups.google.com/group/phonegap/browse_thread/thread/8a95dfeb0f313792/3ff10d8f35211739?lnk=gst&q=detect+desktop+browser#3ff10d8f35211739

None of which work, unless you remove the PhoneGap Javascript file from the desktop version of the app, which defeats my goal of having one codebase.

So far the only solution I have come up with is browser / user agent sniffing, but this is not robust to say the least. Any better solutions welcome!

EDIT: A marginally better solution is to try calling a PhoneGap function after some small timeout - if it doesn't work, then assume the user is on a desktop web browser.