Behavior of pv_name property change

[georgweiss]

A user is pointing out that for the Array widget, changing the pv name property with a rule does not trigger the expected change, i.e. it does not connect to a different PV.

Investigating this I conclude that it looks like only three widgets support a change in the pv name property such that the widget connects to a different PV: text update, spinner and text input.

If this is truly the case, is this by design or simply not yet implemented in other PV-aware widgets?

[georgweiss]

Any thoughts here, @kasemir, @shroffk ?

[kasemir]

The need to change PV names used to simply not come up in EPICS display tools. You can use action buttons to open related displays, we have the navigation tabs to tab through different displays, but you generally can't change the names of PVs in a running display .. unless there's support for scripts that do it.
I'm not opposed to you implementing perfect runtime pv name change support.

[georgweiss]

Thanks @kasemir for your input.

but you generally can't change the names of PVs in a running display

My conclusion is that it is indeed supported for text update, spinner and text input.

Taking the user perspective, changing the PV name is offered in the rule editor, so quite naturally they get confused when it's not working the way the expect. As for the use case... I would agree that it may be a bad practice to let a UI element show a value from one PV only to later show a value from another PV. But I guess one would want to save space, or reduce visual clutter, by switching the PV.