% \iffalse meta-comment
%
% Copyright (C) 2020 by David Gustavsson
%
% This file may be distributed and/or modified under the
% conditions of the LaTeX Project Public License, either
% version 1.3 of this license or (at your option) any later
% version. The latest version of this license is in:
%
% http://www.latex-project.org/lppl.txt
%
% and version 1.3 or later is part of all distributions of
% LaTeX version 2005/12/01 or later.
%
% \fi
%
% \iffalse
%<package>\NeedsTeXFormat{LaTeX2e}[2020/02/02]
%<package>\ProvidesPackage{datax}
%<package>	[2020/11/17 v1.1 data import into LaTeX]
%<package>\RequirePackage{pgfkeys}
%<package>\RequirePackage{pgfopts}
%
%<*driver>
\begin{filecontents}{datax-example-data.tex}
	\pgfkeyssetvalue{/datax/s}{A literal string}
	\pgfkeyssetvalue{/datax/x}{\num{2.4}}
	\pgfkeyssetvalue{/datax/c}{\SI{3e8}{\meter\per\second}}
\end{filecontents}
\documentclass{ltxdoc}
\usepackage[dataxfile=datax-example-data.tex]{datax}
\usepackage{booktabs}
\usepackage{siunitx}
\usepackage[hidelinks]{hyperref}

\EnableCrossrefs
\CodelineIndex
\RecordChanges
\begin{document}
\DocInput{datax.dtx}
\end{document}
%</driver>
% \fi
%
%\CheckSum{19}
%
% \CharacterTable
%  {Upper-case    \A\B\C\D\E\F\G\H\I\J\K\L\M\N\O\P\Q\R\S\T\U\V\W\X\Y\Z
%   Lower-case    \a\b\c\d\e\f\g\h\i\j\k\l\m\n\o\p\q\r\s\t\u\v\w\x\y\z
%   Digits        \0\1\2\3\4\5\6\7\8\9
%   Exclamation   \!     Double quote  \"     Hash (number) \#
%   Dollar        \$     Percent       \%     Ampersand     \&
%   Acute accent  \'     Left paren    \(     Right paren   \)
%   Asterisk      \*     Plus          \+     Comma         \,
%   Minus         \-     Point         \.     Solidus       \/
%   Colon         \:     Semicolon     \;     Less than     \<
%   Equals        \=     Greater than  \>     Question mark \?
%   Commercial at \@     Left bracket  \[     Backslash     \\
%   Right bracket \]     Circumflex    \^     Underscore    \_
%   Grave accent  \`     Left brace    \{     Vertical bar  \|
%   Right brace   \}     Tilde         \~}
%
% \changes{v1.0}{2020/11/15}{Initial version}
%
% \GetFileInfo{datax.sty}
% \DoNotIndex{}
%
% \title{The \textsf{datax} package\thanks{This document 
%     corresponds to \textsf{datax}~\fileversion,
%     dated~\filedate.}}
% \author{David Gustavsson \texttt{david.e.gustavsson@gmail.com}}
%
% \maketitle
%
% \section{Motivation}
% \textsf{datax} allows you to export data from your scripts, and import them as \textsf{siunitx} commands.
% This is analogous to how the author uses \textsf{graphicx} to programmatically generate graphics and include
% in a document.
%
% \section{Installation}
% Place |datax.sty| in a place where \LaTeX{} can find it (often |~/texmf/tex/latex/datax/datax.sty|). Run |texhash| if needed. 
%
% \section{Usage}
% The package is loaded with |\usepackage[dataxfile=|\meta{data.tex}|]{datax}|, which reads the file specified as
% \meta{dataxfile}.
%
% \DescribeMacro{\datax}
% From then on data can be inserted as |\datax|\marg{tag}. If the file |data.tex| contains references
% to a string \(s\), a number \(x\) and a physical constant \(c\), then the macro produces this output:
%
% \begin{center}
%     \begin{tabular}{rl}\toprule
%         Input & Output \\\midrule
%         |\datax{s}| & \datax{s} \\
%         |\datax{x}| & \datax{x} \\
%         |\datax{c}| & \datax{c} \\
%         |\datax{undefined}| & \datax{undefined} \\
%         \bottomrule
%     \end{tabular}
% \end{center}
%
% \section{Interactions}
% Technically, \textsf{datax} only needs a data file consisting of a number of assignments:
% |\pgfkeyssetvalue{/datax/|\meta{tag}|}{|\meta{value}|}|
% but of course the entire point of the package is automation. For this, you need an interaction plugin for your script
% language. If your language is not listed below, you might need to write this plugin for yourself, or request it.
% \begin{center}
% \begin{tabular}{rlp{5cm}}\toprule
% Language & Plugin & Comments\\\midrule
% |julia| & \href{https://github.com/Datax-package/Datax.jl}{Datax.jl} & By the current author \\
% |Matlab| & \href{https://github.com/Datax-package/Datax.m}{Datax.m} & By the current author \\
% \bottomrule
% \end{tabular}
% \end{center}
%
% \StopEventually{\PrintIndex}
% \section{Implementation}
% 
%    \begin{macrocode}
\pgfkeys{ %
	/packageoptions/dataxfile/.initial=data.tex, %
}
\ProcessPgfPackageOptions{/packageoptions}

\pgfkeys{ %
	/datax/.is family, datax, %
	.unknown/.code={ %
		\pgfkeyssetvalue{ %
			\pgfkeyscurrentpath/\pgfkeyscurrentname %
			}{ %
			#1 %
		} %
	}, %
}

\def\dataxfile{./\pgfkeysvalueof{/packageoptions/dataxfile}}
\InputIfFileExists{%
	\dataxfile
	}{}{
	\PackageWarning{datax}{Cannot read file `\dataxfile'}
}
%    \end{macrocode}
% \begin{macro}{\datax}
% Include datum from the specified data file.
%    \begin{macrocode}
\newcommand{\datax}[1]{
	\pgfkeysifdefined{/datax/#1}{ %
		\pgfkeysvalueof{/datax/#1} %
		}{ %
		\PackageWarning{datax}{Data value `#1' undefined}\textbf{??} %
	} %
}
%    \end{macrocode}
% \end{macro}
% \Finale
\endinput
