Lock or change orientation on Android using NativeScript

We need to lock or change the device orientation to see a video or play a game etc. You can do so in Android using NativeScript as follows:

function lockOrientation(orientation) {
    var activity = application.startActivity;
    switch (orientation) {
        case 'unlocked':
            activity.setRequestedOrientation(android.content.pm.ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED);
            break;

        case 'portrait-primary':
            activity.setRequestedOrientation(android.content.pm.ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
            break;

        case 'portrait-secondary':
            activity.setRequestedOrientation(android.content.pm.ActivityInfo.SCREEN_ORIENTATION_REVERSE_PORTRAIT);
            break;

        case 'landscape-primary':
            activity.setRequestedOrientation(android.content.pm.ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
            break;

        case 'landscape-secondary':
            activity.setRequestedOrientation(android.content.pm.ActivityInfo.SCREEN_ORIENTATION_REVERSE_LANDSCAPE);
            break;

        case 'portrait':
            activity.setRequestedOrientation(android.content.pm.ActivityInfo.SCREEN_ORIENTATION_SENSOR_PORTRAIT);
            break;

        case 'landscape':
            activity.setRequestedOrientation(android.content.pm.ActivityInfo.SCREEN_ORIENTATION_SENSOR_LANDSCAPE);
            break;

        default: activity.setRequestedOrientation(android.content.pm.ActivityInfo.SCREEN_ORIENTATION_SENSOR_PORTRAIT);
            break;
    }
}

When ever you need to set or remove the orientation call the function like this:

lockOrientation('unlocked');
or
lockOrientation('landscape');