More complicated key definitions in loops/for each statements

Question

While writing a package with a key-value interface, I had a lot of repetitive key definitions. Naturally, one would like to express these definitions with a loop. When the definition contains something more complicated like \PassOptionsToPackage, things get messy. The degree of messiness depends on the package used for the loops. etoolbox complains a lot, forarray not so much. Minimal working example for forarray:

    \NeedsTeXFormat{LaTeX2e}[1994/12/01]
    \ProvidesPackage{package}
    [2012/09/18 Example]
    \RequirePackage{keyreader}
    \RequirePackage{forarray}
    \DeclareOptionX*{%
    \PackageWarningNoLine{}{Cant understand option(s): \CurrentOption}%
    }

    \CommandForEach{,}{%
    \krdDeclareOption{#1}{\PassOptionsToPackage{##1}{#1}}%
    }%
    {todonotes}

    \krdProcessOptions

This is the package, and the latex file is

    \documentclass{article}

    \usepackage[todonotes=shadow]{package}
    \usepackage{todonotes}

    \begin{document}
    \todo{2 do}
    \end{document}

This produces the warning

    ! LaTeX Error: Missing \begin{document}.

    See the LaTeX manual or LaTeX Companion for explanation.
    Type  H <return>  for immediate help.
     ...                                              

    l.13 {todonotes}

    ? 

No greater harm done, pressing return brings it to the end. Only the todonotes in the documents remains of the trouble, but the todo box has a nice shadow. What is wrong here?

Answer 1

Solution using \comma@parse of kvsetkeys:

\NeedsTeXFormat{LaTeX2e}[1994/12/01]
\ProvidesPackage{package}[2012/09/18 Example]
\RequirePackage{keyreader}
\RequirePackage{kvsetkeys}
\DeclareOptionX*{%
  \PackageWarningNoLine{}{Cant understand option(s): \CurrentOption}%
}
\def\TempDefOption#1{%
  \krdDeclareOption{#1}{\PassOptionsToPackage{##1}{#1}}%
}
\comma@parse{todonotes}\TempDefOption

\krdProcessOptions

Answer 2

Another (or, more precisely, the same) solution with etoolbox:

\NeedsTeXFormat{LaTeX2e}[1994/12/01]
\ProvidesPackage{package}
[2012/09/18 Example]
\RequirePackage{keyreader}
\RequirePackage{etoolbox}

\renewcommand*{\do}[1]{%
  \krdDeclareOption{#1}{\PassOptionsToPackage{##1}{#1}}%
}

\docsvlist{todonotes}

\krdProcessOptions

As I tested Heikos solution I realized that earlier with etoolbox, I just had forgotten a closing curly bracket while redefining \do. Sorry for the hassle, I still hope it was useful.

Answer 3

What you actually need is something like the following. You don't have to load etoolbox or any package for processing a list. The keyreader package has its own list processors.

\NeedsTeXFormat{LaTeX2e}[2011/06/27]
\ProvidesPackage{ulysis}[2012/09/18 Example package]
\RequirePackage{keyreader}
\krdDeclareOption*{%
  \PackageWarningNoLine{ulysis}{Unknown option `\CurrentOption' ignored}%
}
\newif\ifuly@verbose
\krdDeclareOption{verbose}[true]{\@nameuse{uly@verbose#1}}

% Declare options with default values that will be used when the options
% are called without user values:
\protected\def\DeclarePassedOptions#1{%
  \edef\uly@tempa{\unexpanded{#1}}%
  \krdkvnormalize\uly@tempa
  % The looping macro used here is \krdfor, but the list has to be first normalized.
  \def\do##1{%
    \def\@do####1=####2=####3\@nil{%
      \krdDeclareOption{####1}[####2]{%
        \PassOptionsToPackage{########1}{####1}%
      }%
      % To avoid passing options to eventually unloaded packages:
      \AtBeginDocument{%
        \ifuly@verbose
          \krdifcsndef{ver@####1.sty}{}{%
            \@latexerr{Package '####1' wasn't loaded}
              {There are specified but unloaded packages}%
          }%
        \fi
      }%
    }%
    \@do##1==\@nil
  }%
  \expandafter\krdfor\expandafter{\uly@tempa}%
}
\DeclarePassedOptions{%
  todonotes={backgroundcolor=gray!15},xcolor=svgnames
}
\krdProcessOptions*

\endinput

Test document:

\documentclass[12pt]{article}
\usepackage[
  verbose,
  todonotes={shadow,linecolor=red,backgroundcolor=white},
  xcolor=dvipsnames
]{ulysis}
\usepackage{todonotes}
\usepackage{xcolor}

\begin{document}
\textcolor{MidnightBlue}{%
  \todo{{\bf\large 1 do}}
}

\textcolor{ForestGreen}{%
  \todo{\bf\large 2 do}
}
\end{document}