Re: [Flightgear-devel] Listener not firing, 10Hz nasal loop harmful?

[James T. <ja...@fl...>]

> On 6 Jun 2023, at 08:34, Benedikt Hallinger <be...@ha...> wrote:
> 
> i stripped down the code to a basic example. and that seems to work.
> 

	That is slightly what I expected, and re-assuring (waring my core-maintainer hat)

> When i have a Prop node A, and it changes its value, do the aliased props also fire a listener?
> 
> A<-alias B     setlistener(B)
> When A changes, the new value can be read from B; but does an setlistener to B also fire when the underlaying prop A changes?

I thought this did work, but apparently it does not : aliases are bit liked tied properties in this regard.

We could fix this, it would require SGPropertyNode::alias to chain to its target’s listeners. (Target nodes don’t know they are aliased, so we can’t ‘forward fire’ the aliases)

I suspect people have mostly just worked around this (now I think, I have worked around it once myself) … but it breaks the useful-ness / abstraction of aliasing quite badly.

Kind regards,
James