feature testing

When reading Ashley tutorial about fullscreen and orientation lock in browsers:

https://www.scirra.com/tutorials/1282/f ... n-browsers

I was wondering if there was any reliable way to test if those features exists, or are supported by the browser the user is using so we do not for exemple, show a button if the related feature does not work.

Of course trying to detect the browser itself and do a manual change like "if on safari, do nothing, else if on chrome, do this, else do that" is not an option (the whole concept is to have one codebase, not one per browser).

Good point, I could add an option to check requesting fullscreen is supported. However does there really need to be a condition to check orientation lock is supported? You wouldn't typically have any in-game difference for that, right?

I was talking for fullscreen support, indeed fullscreen locking not being supported has already enough fallbacks (we know if it is portrait or landscape, largely enough to make the game respond correctly) and it is a non essential feature (a passive, if you will) so I do not ask for a check for it.