[NTG-context] Foonotes in Captions ... again

[denis.maier at unibe.ch]

Thanks, Max! That's very neat, and it indeed works in my use case.

Can anyone see any drawbacks here?

Best,
Denis

> -----Ursprüngliche Nachricht-----
> Von: Max Chernoff <mseven at telus.net>
> Gesendet: Donnerstag, 16. Juni 2022 01:32
> An: ntg-context at ntg.nl
> Cc: Maier, Denis Christian (UB) <denis.maier at unibe.ch>
> Betreff: Re: [NTG-context] Foonotes in Captions ... again
> 
> > What's the current state of affairs regarding footnotes in floats? Both
> version in the example below don't quite work...
> > (Ideally, the note should be on the page with the float and the
> > caption, but the numbering should also be adjusted.)
> 
> We can completely abuse a bunch of different ConTeXt features to ensure
> that the footnote numbers are always in the page order.
> 
>      % New Code
>      \unprotect
> 
>      \startluacode
>          userdata.visual_order = 0
>          userdata.input_order = 0
>          userdata.save_data = job.passes.define("saved_footnotes")
>          userdata.previous_data = job.passes.getcollected("saved_footnotes")
> 
>          interfaces.implement {
>              name = "set_footnote_number",
>              actions = function ()
>                  userdata.input_order = userdata.input_order + 1
> 
>                  local input_index = userdata.input_order
>                  local page_index = userdata.previous_data[input_index]
> 
>                  if page_index then
>                      structures.counters.set("footnote", 1, page_index - 1)
>                  end
>              end
>          }
>      \stopluacode
> 
>      \def\save_footnote_data#1{%
>          \latelua{
>              userdata.visual_order = userdata.visual_order + 1
>              userdata.save_data[#1] = userdata.visual_order
>          }%
>      }
> 
>      \let\old_footnote=\footnote
> 
>      \starttexdefinition protected footnote #1
>          \begingroup
>              \clf_set_footnote_number
> 
>              \def\insert##1\bgroup##2\egroup{
>                  \normalexpanded{
>                      \noexpand\save_footnote_data
>                      {\cldcontext{userdata.input_order}}
>                  }
>                  \normalinsert##1{##2}
>              }
> 
>              \old_footnote{#1}
>          \endgroup
>      \stoptexdefinition
> 
>      \protect
> 
>      % Original Example
> 
>      \starttext
> 
>      \footnote{asdf} \footnote{asdf} \footnote{asdf}
> 
>      \input ward
> 
>      \startplacefigure[title={asdfasdf\footnote{test 1}}]
>      \externalfigure[cow.pdf]
>      \stopplacefigure
> 
>      \footnote{asdf} \footnote{asdf} \footnote{asdf}
> 
>      \startplacefigure[title={asdfasdf\footnote{test 2}}]
>      \externalfigure[cow.pdf][height=10cm]
>      \stopplacefigure
> 
>      \footnote{asdf} \footnote{asdf} \footnote{asdf}
> 
> 
>      \page
>      \footnote{asdf} \footnote{asdf} \footnote{asdf}
> 
>      \input ward
> 
>      \startplacefigure[title={asdfasdf\footnote{test 1}}]
>      \externalfigure[cow.pdf]
>      \stopplacefigure
> 
>      \footnote{asdf} \footnote{asdf} \footnote{asdf}
> 
>      % (Can't use postponingnotes)
>      % \startpostponingnotes
>      \startplacefigure[title={asdfasdf\footnote{test 2}}]
>      \externalfigure[cow.pdf][height=10cm]
>      \stopplacefigure
>      % \stoppostponingnotes
> 
>      \footnote{asdf} \footnote{asdf} \footnote{asdf}
>      \stoptext
> 
> Here, we save a mapping between each footnote's index in the input and its
> index in the output to the .tuc file. The code is definitely not pretty, but
> works well enough for the sample file provided.
> 
> -- Max