Check if device supports ScreenOrientation.lock() – Uncaught Error screen.orientation.lock() is not available on this device

I’m following the documentation for ScreenOrientation.lock() but I can’t get it to work as I want.

https://developer.mozilla.org/en-US/docs/Web/API/ScreenOrientation/lock

When calling window.screen.orientation.lock("portrait"); on Chrome desktop I get the error screen.orientation.lock() is not available on this device. as a Uncaught Error. Is there anyway to check if a device supports locking?

I have already put "orientation":"portrait" into manifest.json but this is only default orientation and not a lock.

https://www.w3.org/TR/appmanifest/#orientation-member

Side notes:

I had some trouble understanding how to call the method. Example errors if anyone finds this thread:

ScreenOrientation.prototype.lock("portrait");

window.ScreenOrientation.prototype.lock("portrait");

Leads to this exception:

Unhandled Rejection (TypeError): Failed to execute ‘lock’ on ‘ScreenOrientation’: Illegal invocation

(ScreenOrientation as any).lock("portrait");

Leads to this exception:

TypeError: ScreenOrientation.lock is not a function

Answer

window.screen.orientation.lock() returns a Promise. A promise will call one of the functions that you provide to a chained then() method, depending on whether the promise was resolved (success) or rejected (failure).

You could make your call to window.screen.orientation.lock() like this:

window.screen.orientation
    .lock("portrait")
    .then(
        success => console.log(success),
        failure => console.log(failure)
    )

You will probably want to put something more useful in the resolve and reject methods, but this will at least catch the rejection and prevent an Unhandled Rejection error from being thrown.