Bug in get_peer_name in Element?

[TeresiaOlsson]

In Element there is the following function:

    def get_peer_name(self) -> str:
        """
        Returns a string representation of peer simulator or control system
        """
        return "None" if self._peer is None else f"{self._peer.__class__.__name__}:{self._peer.name()}"

If I understand correctly peer is an ElementHolder but ElementHolder doesn't seem to have a function name or any other attributes/functions related to name. Is this a bug?

Also, is this function really needed since there is also a property for peer so if peer has an attribute name can't you just get it with peer.name without needing a dedicated function for it in the Element class?

[gubaidulinvadim]

I think it works correctly:

In [7]: bpm0.get_peer_name()
Out[7]: 'TangoControlSystem:live'

In [8]: bpm0d = sr.design.get_bpms('BPM')[0]

In [9]: bpm0d.get_peer_name()
Out[9]: 'Simulator:design'

And also explains why it's there. You can check where the object you work with belongs: in design or in live mode, or in some other mode.

[kparasch]

From what I understand, ElementHolder is only inherited in practice by the Simulator or ControlSystem. Simulator has name() implemented, while ControlSystem has it as an abstract method which must be implemented in the corresponding control system class.

[TeresiaOlsson]

Ah, it currently works because both ControlSystem and Simulator implements it despite it not being in the ElementHolder.

I think that means it is a bug and name should be added in ElementHolder or potential new classes that inherits from it will throw an error. Alternatively, it should be specified in Element that the type of peer is either ControlSystem or Simulator and not a generic ElementHolder.

[gubaidulinvadim]

It is generic in Element to account for future control modes. But it's true that there should be an abstract name().

[TeresiaOlsson]

I will make a PR for it but does it mean that ElementHolder should actually have a name attribute already in __init__? Or it should be allowed to create an ElementHolder without a name and only have subclasses enforcing it?