I am using passport-facebook with expressjs and passportjs
I want to know how we can set the display parameter as touch so that when our android device gets the required url to login and allow apps, it will be displayed such that it can be rendered properly for mobiles.
That parameter isn't a standard OAuth 2.0 parameter, so there isn't support for it yet in the Facebook strategy. However, there are hooks for this, and if you file an issue, I'll add support for it.
If you want to take a crack at adding support yourself, see this line in the Google OAuth 2.0 strategy. It parses options passed to the authenticate call, and determines which should be added to as params to the authorization URL.
Once support is in place, you'll then be able to do something like:
passport.authenticate('facebook', { display: 'touch' })