Re: Scheme code for extracting LilyPond header properties?

[John Zaitseff]

Dear Nicolas / LilyPonders,

Nicolas Sceaux wrote:
>
> John Zaitseff writes:
> 
> > [...]  What I would like to do, however, is to replace the
> > "\fromproperty #'header:maintainer" with something like:
> >
> >     \with-url #"mailto:address@hidden";
> >         \fromproperty #'header:maintainer
> >
> > except that I would like to extract the actual e-mail address
> > from header:maintainerEmail: something like:
> >
> >     \with-url #(string-append "mailto:"; XXX)
> 
> Ok so basicaly you want a \email-property markup command that
> looks for a header property and outputs something equivalent to:
> 
>   \with-url #"mailto:..."; "..."
> 
> [ Actual detailed explanation follows... ]

Thank you very much for your help!  I actually wrote the function
to take the header:maintainer AND header:maintainerEmail properties
into account:

  % \email-property EMAIL ARG - add a mailto link based on property EMAIL
  #(define-markup-command (email-property layout props email arg)
                          (symbol? markup?)
      "Add a mailto link to property @var{email} around @var{arg}.
  This only works in the PDF backend."
      (let* ((address (chain-assoc-get email props)))
          (interpret-markup layout props
              (if (string? address)
                  (markup #:with-url (string-append "mailto:"; address) arg)
                  arg))))

For other people's edification :-), the following is my tagline:

  tagline = \markup {
      \fontsize #-3.5
      \override #'(word-space . 0)
      \line {
          "Typeset by "
          \email-property #'header:maintainerEmail
              \fromproperty #'header:maintainer
          " using "
          \with-url #"http://www.lilypond.org/";
              \line {
                  "LilyPond "
                  #(ly:export (string-append (lilypond-version) "."))
              }
          "  File version "
          \fromproperty #'header:version
          ", last modified "
          \parsed-date #'header:lastupdated
          "."
      }
  }

I store a field in the header, lastupdated, in the form "09-Oct-2007";
the \parsed-date function converts that to something like "9 October,
2007":

  % \parsed-date DATE - convert a DD-MMM-YYYY property to a fully printed date
  #(define-markup-command (parsed-date layout props date) (symbol?)
      "Convert the property @var{date} containing a date in the
  form DD-MMM-YYYY into a nicely formatted stencil output D MMMM,
  YYYY."
      (let* ((datestr (chain-assoc-get date props)))
          (interpret-markup layout props
              (if (string? datestr)
                  (markup #:simple
                      (strftime "%e %B, %Y" (car (strptime "%d-%b-%Y" 
datestr))))
                  datestr))))

(Of course, I should rewrite that to make it somewhat more robust.
It works for me, however).


Once again, thank you for your help.

Yours truly,

John Zaitseff

-- 
John Zaitseff                    ,--_|\    The ZAP Group
Phone:  +61 2 9643 7737         /      \   Sydney, Australia
E-mail: address@hidden   \_,--._*   http://www.zap.org.au/
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