%D \module
%D   [       file=x-xfdf,
%D        version=2011.09.07,
%D          title=\CONTEXT\ XML Modules,
%D       subtitle=\XFDF,
%D         author=Hans Hagen,
%D           date=\currentdate,
%D      copyright={PRAGMA ADE \& \CONTEXT\ Development Team}]
%C
%C This module is part of the \CONTEXT\ macro||package and is
%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
%C details.

%D This is a revival of using \XFDF, but now in a more \MKIV-ish way. We
%D supported it long ago already in \MKII\ but never used it at a large
%D scale (not that much user interest anyway).

\startmodule[xfdf]

% see xfdf-001.xfdf and xfdf-001.tex

% %D Possible speedup but hardly worth the trouble.
%
% \startluacode
%
%     local hashes = { } table.setmetatableindex(hashes,function(t,k) local v = { } t[k] = v return v end)
%
%     function xml.functions.xfdf_collect_values(root)
%         local hash = hashes[root]
%         for c in xml.collected(root,"/xfdf/fields/field/value") do
%             hash[xml.parent(c).at.name] = c
%         end
%     end
%
%     function xml.functions.xfdf_get_values(root,name)
%         return hashes[root][name]
%     end
%
%     function lxml.xfdf_get_values(root,name)
%         xml.sprint(hashes[lxml.id(root)][name])
%     end
%
% \stopluacode
%
% \def\xfdfvalue#1#2%
%   {\ctxlua{lxml.xfdf_get_values("#1","#2")}}

\startxmlsetups xfdf:define
    \xmlsetsetup{#1}{*}{xfdf:*}
  % \xmlfilter  {#1}{./function(xfdf_collect_values)}
\stopxmlsetups

\xmlregisterns{xfdf}{http://ns.adobe.com/xfdf/}

\xmlregisterdocumentsetup{xfdf}{xfdf:define}

\startxmlsetups xfdf:value
    \xmlflush{#1}
\stopxmlsetups

\def\xfdfload #1#2{\xmlloadonly{#1}{#2}{xfdf}}
\def\xfdfvalue#1#2{\xmlfirst{#1}{/xfdf/fields/field[@name='#2']/value}}
\def\xfdftext #1#2{\xmlfirst{#1}{/xfdf/fields/field[@name='#2']/value/paragraphs()}}

% \startxmlsetups xfdf:b
%     \bold{\xmlflush{#1}}
% \stopxmlsetups

% \xfdfload {whatever}{xfdf-001.xfdf}
% \xfdfvalue{whatever}{somefield}

\stopmodule