barnumber | post-event in music function

[Urs Liska]

Hi Scheme wizards, can you help me?

I have two unrelated questions regarding the attached file.
It is a very much stripped down version of a function actually in use.

It takes an annotation from the input file, produces a clickable message on the console and colors the affected object. (In reality it does and will do more, but that's what's necessary for the example/question).

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The first question should be quite simple, but I don't seem to find a solution on my own: How can I make the function be able to affect only selected items, e.g. only one note of the chord in the example (or only a specific tie etc.)

When I change the \once \override clause to

\tweak color #magenta #item

it colors all subsequent items of the given type.

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The other issue is probably trickier. Is it possible (at all) to determine the current barnumber from within such a music function? I want to print that to the console along with the other arguments and particularly to annotation files.
Is there any hope in achieving that?

TIA
Urs

annotate.ly
Description: Text Data