Detect Facebook Mobile Browser

Question

Is it somehow possible to detect Facebook's mobiles apps' browser via PHP or JS? My apps all have problems inside their browser (in native browser not!) and I want to show a warning notice.

Alternatively, is there a possibility to directly open the website in a external browser?

Answer 1

This works fine for me in JavaScript:

if (navigator.userAgent.match(/(iPod|iPhone|iPad)/) && navigator.userAgent.match(/FBAV/i)) {
    //iOS Facebook App Browser detected
}

More information about the User Agent: Is this a Facebook for iOS WebView User Agent?

Afaik it´s not possible to force the website to open in any external browser, only the user can do that.