Re: Make TOC entries available to LaTeX

[Urs Liska]

Hi Harm

Am 19.04.2018 um 23:23 schrieb Thomas Morley:

2018-04-19 16:19 GMT+02:00 Urs Liska <address@hidden>:

Hi all,

I'm preparing an automated edition process using LuaLaTeX, Pandoc and
LilyPond.

After some experimentation I have come to the conclusion that I'll have to
insert the multi-movement score as a single PDF created by LilyPond (but
through lyluatex to make use of caching and the layout mechanics).

I first had used lyluatex's facility to include the score's system by system
and print all the titles with LaTeX, but this didn't work out - for the
first time I realized that lilypond-book-preamble.ly makes the vertical
staff-staff spacing as tight as possible, which often makes the page layout
pretty bad. Creating the movements separately is not an option either
because not all movements will start on a new page.

So now I have included a multi-movement score in the LaTeX document and
don't know how to add TOC entries (in LaTeX) for the movements. I can see
two possible ways, but don't know if they are really possible and if so how
to approach them:

Is it possible to insert something in the PDF output that LaTeX can pick up
as TOC entries?
(actually I doubt this is possible, but since it would be the easiest way I
thought I'd ask anyway)
Can I reliably retrieve the current page number of a given score's title
block?
With that information I could write them to a log file and read that later
in LaTeX.

TIA
Urs

PS: I don't know if it matters but the file is produced using
ly:book-process etc.

Doesn't
http://lilypond.org/doc/v2.19/Documentation/usage-big-page#sharing-the-table-of-contents
do what you want?

Thank you, yes, this is what I needed, and finally I got the time to make it work.
I must admit I wouldn't have thought about looking in the *usage* manual for that information.

On closer inspection of the code I have some questions about it.

%%%
#(define (oly:create-toc-file layout pages)
  (let* ((label-table (ly:output-def-lookup layout 'label-page-table)))
    (if (not (null? label-table))
      (let* ((format-line (lambda (toc-item)
             (let* ((label (car toc-item))
                    (text  (caddr toc-item))
                    (label-page (and (list? label-table)
                                     (assoc label label-table)))
                    (page (and label-page (cdr label-page))))
               (format #f "~a, section, 1, {~a}, ~a" page text label))))
             (formatted-toc-items (map format-line (toc-items)))
             (whole-string (string-join formatted-toc-items ",\n"))
             (output-name (ly:parser-output-name))
             (outfilename (format "~a.toc" output-name))
             (outfile (open-output-file outfilename)))
        (if (output-port? outfile)
            (display whole-string outfile)
            (ly:warning (_ "Unable to open output file ~a for the TOC information") outfilename))
        (close-output-port outfile)))))

\paper {
  #(define (page-post-process layout pages) (oly:create-toc-file layout pages))
}
%%%

1)
If I see correctly the inner let* will only be evaluated if 'label-page-table has successfully been found and is not empty.
If this object is not found or if there are no TOC entries in the file label-table will be an empty list, right?
If that's true the (and (list? label-table) ... is redundant, isn't it?

2)
Assuming the TOC items are created using \tocItem then it should be guaranteed that there is the same label present as key in both label-table and one of the (toc-items) sublists. So (IISC) several further checks could be removed additionally (or am I missing something?):

             (let* ((label (car toc-item))
                    (text  (caddr toc-item))
                    (page (assoc-ref label-table label)))

should be sufficient? Therefore the whole function could be written as

#(define (oly:create-toc-file layout pages)
  (let* ((label-table (ly:output-def-lookup layout 'label-page-table)))
    (if (not (null? label-table))
      (let* ((format-line (lambda (toc-item)
             (let* ((label (car toc-item))
                    (text  (caddr toc-item))
                    (page (assoc-ref label-table label)))
               (format #f "~a, section, 1, {~a}, ~a" page text label))))
             (formatted-toc-items (map format-line (toc-items)))
             (whole-string (string-join formatted-toc-items ",\n"))
             (output-name (ly:parser-output-name))
             (outfilename (format "~a.toc" output-name))
             (outfile (open-output-file outfilename)))
        (if (output-port? outfile)
            (display whole-string outfile)
            (ly:warning (_ "Unable to open output file ~a for the TOC information") outfilename))
        (close-output-port outfile)))))

3)
I think the inclusion in the TeX TOC can (now?) be done in a simpler way using the catchfile package:

\documentclass{article}
\usepackage{pdfpages,catchfile}
\newcommand\includelilypond[1]{%
  \begingroup
    \CatchFileDef\currentlilypondtoc{#1.toc}{}
    \edef\x{\noexpand\includepdf[pages=-,addtotoc={\currentlilypondtoc}]{#1.pdf}}
  \expandafter\endgroup\x
}
\begin{document}
\tableofcontents
\includelilypond{test}
\end{document}

(Answer from https://tex.stackexchange.com/questions/428239/merge-in-manual-toc-entries-in-a-lualatex-document)

There's only one issue: The TOC will create wrong entries when LilyPond's first page number is not 1. So there should actually be an offset in place.
How can I read the value of the first-page-number variable to set up this offset?

Best
Urs

Cheers,
  Harm