Per instance attribute visibility

[spacecheese]

Is your feature request related to a problem? Please describe.
The _Property, _Signal and _Method "disabled" fields are not context aware and therefore a property, signal or method may only be hidden for all instances of a ServiceInterface. This is problematic when implementing interfaces with optional properties (for example org.bluez.LEAdvertisement) where ideally not all instances would include the same optional attributes.

Describe the solution you'd like
disabled could be provided by a Callable[[ServiceInterface], bool] callback. Alternatively the ServiceInterface could maintain a record of which attributes are disabled.

[dlech]

I would suggest to make a class factory function to use the existing functionality.

Totally untested, but it looks like something like this should work:

# In the library, move existing class definition inside of a factory function
# and add disabled=... to all optional properties.

def create_advertisement_interface(disabled_properties: list[str] = []):
    class Advertisement(ServiceInterface):
        ...
        @dbus_property(PropertyAccess.READ, disabled="Appearance" in disabled_properties)
        def Appearance(self) -> "q":  # type: ignore
            return self._appearance
        ...

# Default instance with all properties enabled for backwards compatibility.
Advertisement = create_advertisement_interface()

Then users that don't want all properties enabled can create their own class instead of using the default one.

MyAdvertisement = create_advertisement_interface(disabled_properties=["Appearance"])