Re: SVG export - how might you add classes for all graphical objects?

[Matt Hood]

That's quite handy to know, thanks for your response Carl.

Cheers,
Matt.

On Wed, Jun 30, 2021 at 2:35 AM Carl Sorensen <c_sorensen@byu.edu> wrote:
>
>
>
> On 6/29/21, 2:43 AM, "lilypond-user on behalf of Matt Hood" 
> <lilypond-user-bounces+carl.d.sorensen=gmail.com@gnu.org on behalf of 
> matthood0@gmail.com> wrote:
>
>     Hi everyone,
>
>     I'm working with lilypond output in the browser, using its SVG export
>     function. Lilypond permits attaching attributes to particular kinds of
>     grobs, e.g.:
>
>     {
>       \override NoteHead.output-attributes =
>       #'((class . "NoteHead"))
>       c
>     }
>
>     The above will cause all NoteHead objects to have the following SVG:
>
>     <g class="NoteHead">
>       ...NoteHead grob SVG elements...
>     </g>
>
>     My question is: how can I make it so that all graphical objects have
>     their name in the class attribute?
>
>     I've tried using the following scheme function:
>
>     #(define (add-class grob grob-origin context)
>              (let (name (cdr (assoc 'name
>                                     (ly:grob-property grob 'meta))))
>                 (set! (ly:grob-property grob 'output-attributes) '((class
>     . name)))))
>
>     This successfully (I believe) extracts the correct name, and assigns
>     it to the output-attributes field. As per the instructions in the
>     lilypond documentation, I then attempted to use \applyOutput Score
>     #add-class to apply this function to all graphical objects, but it
>     didn't supply all of the required objects. My attempted code is below:
>
>     \applyOutput Score #add-class
>     \score {
>         \new RhythmicStaff {
>           c'2 c'16 c' c' c' \tuplet 5/4 { c'16 c' c' c' c' }
>         }
>     }
>
>     If I add a print call to the add-class function, I can see that it was
>     called for the objects with the following names from which crucial
>     objects such as NoteHead are missing:
>
>     NonMusicalPaperColumn
>     PaperColumn
>     Clef
>     TimeSignature
>     LedgerLineSpanner
>     StaffSymbol
>     VerticalAxisGroup
>     SystemStartBar
>     SpacingSpanner
>     VerticalAlignment
>     StaffSpacing
>     BreakAlignment
>     LeftEdge
>     BreakAlignGroup
>     BreakAlignGroup
>     BreakAlignGroup
>
> Matt, I'm not an expert on \applyOutput, but it appears to me these are all 
> grobs created by engravers that live in the Score context by default.
>
> You may wish to try \applyOutput to Staff and Voice as well.
>
> Haven't tried it, and don't know if it will work, but it's an idea.
>
> HTH,
>
> Carl
>
>