Re: Function operating on header

[Francisco Vila]

This shows that header fields behave just like plain markups and can be 
used inside other markups:

\header {
  title="The title"
  composer=\markup{Composer of \italic\title }
}
  { b }


On 7/3/20 18:50, Timothy Lanfear wrote:
> On 07/03/2020 14:52, Noeck wrote:
> > > Thank you, Timothy,
> > >
> > > this is how far I got already. It is probably a step in the right
> > > direction. But there are two issues with it:
> > >
> > > 1) I would like to use some Scheme code on the fields (with if etc),
> > >     so I need the 'header:author as a string and #(markup->string …)
> > >     did not work.
> > > 2) Can this be put in a command which I can move to a separate file?
> > >     Like \evaluateHeaders
> > >
> > > Cheers,
> > > Joram
>
> Ok, so here is an example of a function to create a bookpart 
> consisting of a single blank page by clearing all the header 
> variables. It should give some clues about how to construct a header 
> in Scheme,
>
>
> \version "2.19.80"
>
> % Print a blank page
> blankpage = #(define-void-function () ()
>   (let ((bookpart #{ \bookpart { \paper { page-count = 1 
> print-page-number = ##f } \markup \null } #})
>         (header   (make-module))
>         (props    '(dedication title subtitle subsubtitle instrument
>                     poet composer meter arranger opus piece copyright)))
>     (for-each (lambda (prop) (module-define! header prop #f)) props)
>     (ly:book-set-header! bookpart header)
>     (ly:book-add-bookpart! $current-book bookpart)))
--
Francisco Vila, Ph.D. - Badajoz (Spain)
paconet.org , lilypond.es