Re: output-attributes in 2.20.0

[Richard Shann]

On Thu, 2020-08-06 at 11:31 +0200, Jean Abou Samra wrote:
>    > (*) The documentation says "SVG output can optionally contain
>    metadata for graphical objects (grobs) like note heads, rests,
> etc.
>    This metadata can be standard SVG attributes like id and class, or
>    non-standard custom attributes. Specify the attributes and their
> values
>    by overriding a grob’s output- attributes property with a Scheme
>    association list (alist). The values can be numbers, strings, or
>    symbols. For example: " I suggest "SVG output can optionally
> contain
>    metadata for graphical objects (grobs) like note heads, rests,
> etc.
>    This metadata can be standard SVG attributes like id and class, or
>    non-standard custom attributes. Specify the attributes and their
> values
>    by overriding a grob’s output- attributes property with a Scheme
>    association list (alist) or a procedure returning an alist. The
> values
>    can be numbers, strings, or symbols. For example:"
> 
>    This is not specific to output-attributes. Any grob property can
> be set
>    to a callback, that is, a (lambda (grob) ...). This is documented
> here:
>    [1]http://lilypond.org/doc/v2.20/Documentation/extending/callback-
> funct
>    ions

Ah, thank you for that. Does convert-ly normally warn if the
substitution it makes may be wrong? Changing

\override NoteHead.id = #note-id

to

 \override Score.NoteHead.output-attributes.id = #note-id

only works if note-id is *not* a callback as I understand it.

Richard Shann